Category Archives: History of science

Renaissance Science – VIII

In the last two episodes we have looked at developments in printing and art that, as we will see later played an important role in the evolving Renaissance sciences. Today, we begin to look at another set of developments that were also important to various areas of the newly emerging practical sciences, those in mathematics. It is a standard cliché that mathematisation played a central roll in the scientific revolution but contrary to popular opinion the massive increase in the use of mathematics in the sciences didn’t begin in the seventeenth century and certainly not as the myth has it, with Galileo.

Medieval science was by no means completely devoid of mathematics despite the fact that it was predominantly Aristotelian, and Aristotle thought that mathematics was not scientia, that is, it did not deliver knowledge of the natural world. However, the mathematical sciences, most prominent astronomy and optics, had a fairly low status within medieval university culture.

One mathematical discipline that only really became re-established in Europe during the Renaissance was trigonometry. This might at first seem strange, as trigonometry had its birth in Greek spherical astronomy, a subject that was taught in the medieval university from the beginning as part of the quadrivium. However, the astronomy taught at the university was purely descriptive if not in fact even prescriptive. It consisted of very low-level descriptions of the geocentric cosmos based largely on John of Sacrobosco’s (c. 1195–c. 1256) Tractatus de Sphera (c. 1230). Sacrobosco taught at the university of Paris and also wrote a widely used Algorismus, De Arte Numerandi. Because Sacrobosco’s Sphera was very basic it was complimented with a Theorica planetarum, by an unknown medieval author, which dealt with elementary planetary theory and a basic introduction to the cosmos. Mathematical astronomy requiring trigonometry was not hardy taught and rarely practiced.

Both within and outside of the universities practical astronomy and astrology was largely conducted with the astrolabe, which is itself an analogue computing device and require no knowledge of trigonometry to operate.

Before we turn to the re-emergence of trigonometry in the medieval period and its re-establishment during the Renaissance, it pays to briefly retrace its path from its origins in ancient Greek astronomy to medieval Europe.

The earliest known use of trigonometry was in the astronomical work of Hipparchus, who reputedly had a table of chords in his astronomical work. This was spherical trigonometry, which uses the chords defining the arcs of circles to measure angles. Hipparchus’ work was lost and the earliest actual table of trigonometrical chords that we know of is in Ptolemaeus’ Mathēmatikē Syntaxis or Almagest, as it is usually called today.


The chord of an angle subtends the arc of the angle. Source: Wikimedia Commons

When Greek astronomy was appropriated in India, the Indian astronomers replaced Ptolemaeus’ chords with half chords thus creating the trigonometrical ratios now known to us, as the sine and the cosine.

It should be noted that the tangent and cotangent were also known in various ancient cultures. Because they were most often associated with the shadow cast by a gnomon (an upright pole or post used to track the course of the sun) they were most often known as the shadow functions but were not considered part of trigonometry, an astronomical discipline. So-called shadow boxes consisting of the tangent and cotangent used for determine heights and depths are often found on the backs of astrolabes.


Shadow box in the middle of a drawing of the reverse of Astrolabium Masha’Allah Public Library Bruges [nl] Ms. 522. Basically the tangent and cotangent functions when combined with the alidade

  Islamic astronomers inherited their astronomy from both ancient Greece and India and chose to use the Indian trigonometrical half chord ratios rather than the Ptolemaic full cords. Various mathematicians and astronomers made improvements in the discipline both in better ways of calculating trigonometrical tables and producing new trigonometrical theorems. An important development was the integration of the tangent, cotangent, secant and cosecant into a unified trigonometry. This was first achieved by al-Battãnī (c.858–929) in his Exhaustive Treatise on Shadows, which as its title implies was a book on gnonomics (sundials) and not astronomy. The first to do so for astronomy was Abū al-Wafā (940–998) in his Almagest.


Image of Abū al-Wafā Source: Wikimedia Commons

It was this improved, advanced Arabic trigonometry that began to seep slowly into medieval Europe in the twelfth century during the translation movement, mostly through Spain. It’s reception in Europe was very slow.

The first medieval astronomers to seriously tackle trigonometry were the French Jewish astronomer, Levi ben Gershon (1288–1344), the English Abbot of St Albans, Richard of Wallingford (1292–1336) and the French monk, John of Murs (c. 1290–c. 1355) and a few others.


Richard of Wallingford Source: Wikimedia Commons

However, although these works had some impact it was not particularly widespread or deep and it would have to wait for the Renaissance and the first Viennese School of mathematics, Johannes von Gmunden (c. 1380­–1442), Georg von Peuerbach (1423–1461) and, all of whom were Renaissance humanist scholars, for trigonometry to truly establish itself in medieval Europe and even then, with some delay.

Johannes von Gmunden was instrumental in establishing the study of mathematics and astronomy at the University of Vienna, including trigonometry. His work in trigonometry was not especially original but displayed a working knowledge of the work of Levi ben Gershon, Richard of Wallingford, John of Murs as well as John of Lignères (died c. 1350) and Campanus of Novara (c. 200–1296). His Tractatus de sinibus, chordis et arcubus is most important for its probable influence on his successor Georg von Peuerbach.

Peuerbach produced an abridgement of Gmunden’s Tractatus and he also calculated a new sine table. This was not yet comparable with the sine table produced by Ulugh Beg (1394–1449) in Samarkand around the same time but set new standards for Europe at the time. It was Peuerbach’s student Johannes Regiomontanus, who made the biggest breakthrough in trigonometry in Europe with his De triangulis omnimodis (On triangles of every kind) in 1464. However, both Peuerbach’s sine table and Regiomontanus’ De triangulis omnimodis would have to wait until the next century before they were published. Regiomontanus’ On triangles did not include tangents, but he rectified this omission in his Tabulae Directionum. This is a guide to calculating Directions, a form of astrological prediction, which he wrote at the request for his patron, Archbishop Vitéz. This still exist in many manuscript copies, indicating its popularity. It was published posthumously in 1490 by Erhard Ratdolt and went through numerous editions, the last of which appeared in the early seventeenth century.


A 1584 edition of Regiomontanus’Tabulae Directionum Source

Peuerbach and Regiomontanus also produced their abridgement of Ptolemaeus’ Almagest, the Epitoma in Almagestum Ptolemae, published in 1496 in Venice by Johannes Hamman. This was an updated, modernised version of Ptolemaeus’ magnum opus and they also replaced his chord tables with modern sine tables. A typical Renaissance humanist project, initialled by Cardinal Basilios Bessarion (1403–1472), who was a major driving force in the Humanist Renaissance, who we will meet again later. The Epitoma became a standard astronomy textbook for the next century and was used extensively by Copernicus amongst others.


Title page Epitoma in Almagestum Ptolemae Source: Wikimedia Commons

Regiomontanus’ De triangulis omnimodis was edited by Johannes Schöner and finally published in Nürnberg in 1533 by Johannes Petreius, together with Peuerbach’s sine table, becoming a standard reference work for much of the next century. This was the first work published, in the European context, that treated trigonometry as an independent mathematical discipline and not just an aide to astronomy.

Copernicus (1473–1543,) naturally included modern trigonometrical tables in his De revolutionibus. When Georg Joachim Rheticus (1514–1574) travelled to Frombork in 1539 to visit Copernicus, one of the books he took with him as a present for Copernicus was Petreius’ edition of De triangulis omnimodis. Together they used the Regiomontanus text to improve the tables in De revolutionibus. When Rheticus took Copernicus’ manuscript to Nürnberg to be published, he took the trigonometrical section to Wittenberg and published it separately as De lateribus et angulis triangulorum (On the Sides and Angles of Triangles) in 1542, a year before De revolutionibus was published.


Rheticus’ action was the start of a career in trigonometry. Nine years later he published his Canon doctrinae triangvlorvmin in Leipzig. This was the first European publication to include all of the six standard trigonometrical ratios six hundred years after Islamic mathematics reached the same stage of development. Rheticus now dedicated his life to producing what would become the definitive work on trigonometrical tables his Opus palatinum de triangulis, however he died before he could complete and publish this work. It was finally completed by his student Valentin Otto (c. 1548–1603) and published in Neustadt and der Haardt in 1596.


Source: Wikimedia Commons

In the meantime, Bartholomäus Piticus (1561–1613) had published his own extensive work on both spherical and plane trigonometry, which coined the term trigonometry, Trigonometria: sive de solution triangulorum tractatus brevis et perspicuous, one year earlier, in 1595.


Source:. Wikimedia Commons

This work was republished in expanded editions in 1600, 1608 and 1612. The tables contained in Pitiscus’ Trigonometria were calculated to five or six places, whereas those of Rheticus were calculated up to more than twenty places for large angles and fifteenth for small ones. In comparison Peuerbach’s sine tables from the middle of the fifteenth century were only accurate to three places of decimals. However, on inspection, despite the years of effort that Rheticus and Otho had invested in the work, some of the calculations were found to be defective. Pitiscus recalculated them and republished the work as Magnus canon doctrinae triangulorum in 1607.


He published a second further improved version under the title Thesaurus mathematicus in 1613. These tables remained the definitive trigonometrical tables for three centuries only being replaced by Henri Andoyer’s tables in 1915–18.

In the seventeenth century a major change in trigonometry took place. Whereas throughout the Renaissance it had been handled as a branch of practical mathematics, used to solve spherical and plane triangles in astronomy, cartography, surveying and navigation, the various trigonometrical ratios now became mathematical functions in their own right, a branch of purely theoretical mathematics. This transition mirroring the general development in the sciences that occurred between the Renaissance and the scientific revolution, from practical to theoretical science.

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Filed under History of Astronomy, History of Islamic Science, History of Mathematics, History of science, Renaissance Science

Renaissance Science – VII

In the last post we looked at the European re-invention of moveable-type and the advent of the printed book, which played a highly significant role in the history of science in general and in Renaissance science in particular. I also emphasised the various print technologies developed for reproducing images, because they played a very important role in various areas of the sciences during the Renaissance, as we shall see in later posts in this series. Parallel to these technological developments there were two major developments in the arts, which would have a very major impact on the illustration in Renaissance science publications, the (re?)-discovery of linear perspective and the development of naturalism.

Linear perspective is the geometrical method required to reproduce three-dimensional objects realistically on a two-dimensional surface; the discovery or invention of linear perspective is usually attributed to the Renaissance artist-engineer and architect, Filippo Brunelleschi (1377–1446), about whom more below, but already in the Renaissance it was often referred to as a re-discovery. This Renaissance re-discovery trope was very much in line with the general Renaissance concept of a rebirth of classical knowledge. Here the belief that linear perspective was a re-discovery is based on the concept of skenographia in ancient Greek theatre, which consists of using painted flat panels on a stage to give the illusion of depth. This is mentioned in Aristotle’s Poetics (c. 335 BCE) a general work on drama. More importantly, from a Renaissance perspective, it is briefly described in Vitruvius’ De Architectura libri dicem (Ten Books on Architecture) from the first century BCE. Once again, as we shall see later, Vitruvius’ De Architectura played a central role in Renaissance thought. In his Book 7 On Finishing, Vitruvius wrote in the preface:

In Athens, when Aechylus was producing tragedies, Agathachus was the first to work for the theatre and wrote a treatise about it. Learning from this, Democritus and Anaxagoras wrote on the same subject, namely how the extension of rays from a certain established centre point ought to correspond in a natural ration to the eyes’ line of sight, so that they could represent the appearance of buildings in scene painting, no longer by some uncertain method, but precisely, both the surfaces that were depicted frontally, and those that seemed either to be receding or projecting[1].

Of course, ancient Greek theatre flats no longer exist, but some Greek and many more Roman wall paintings have survived, which very obviously display some degree of perspective. However, closer analysis of these paintings has shown that while they are in fact constructed on some sort of perspective scheme it is not the linear perspective that was developed in the Renaissance.


Villa of P. Fannius Synistor Cubiculum M alcove Panel with temple at east end of the alcove, the north end of the east wall Middle of the first century B.C. Boscoreale (Pompeii), Italy Source:

Although linear perspective was not strictly a re-discovery, it also didn’t emerge at the beginning of the fifteenth century out of thin air. Already, more than a century earlier the so-called proto-Renaissance artists, in particular Giotto (1267–1337), were producing paintings that displayed depth based on a mathematical model, when not quite that of linear perspective and not consistent.


‘Jesus Before the Caïf’, by Giotto (1305). The ceiling rafters show the Giotto’s introduction of convergent perspective. B. Detailed analysis, however, reveals that the ceiling has an inconsistent vanishing point and that the Caïf’s dais is in parallel perspective, with no vanishing point. Source

At the beginning of the fifteenth century, the Renaissance sculptor Lorenzo Ghiberti (1378–1455) used linear perspective in the panels of the second set of bronze doors he was commissioned to produce for the Florence Baptistry, dubbed the Gates of Paradise by Michelangelo.


A panel of Adam and Eve in Ghiberti’s “Gate’s of Paradise”. Photo by Thermos.Source: Wikimedia Commons

As already stated, Brunelleschi is credited with having invented linear perspective according to his biographer Antonio di Tuccio Manetti (1423–1497), he compared the reality of his painting using linear perspective of the Florence Baptistery with the building itself using mirrors.


Filippo Brunelleschi in an anonymous portrait of the 2nd half of the 15th century (Louvre, Paris) via Wikimedia Commons

According to Manetti, he used a grid or set of crosshairs to copy the exact scene square by square and produced a reverse image. The results were compositions with accurate perspective, as seen through a mirror. To compare the accuracy of his image with the real object, he made a small hole in his painting, and had an observer look through the back of his painting to observe the scene. A mirror was then raised, reflecting Brunelleschi’s composition, and the observer saw the striking similarity between the reality and painting. Both panels have since been lost. (Wikipedia)


Brunelleschi left no written account of how he constructed his painting and the first written account we have of the geometry of linear perspective is from another Renaissance humanist artist and architect, Leon Battista Alberti (1404–1472) in his book On painting, published in Tuscan dialect as Della Pittura in 1436/6 and in Latin as De pictura first in 1450, although the Latin edition was also written in 1435. The book contains a comparatively simple account of the geometrical rudiments of linear perspective.


Presumed self-portrait of Leon Battista Alberti Source: Wikimedia Commons


Figure from the 1804 edition of Della pittura showing the vanishing point Source: Wikimedia Commons

A much fuller written account of the mathematics of linear perspective was produced in manuscript by the painter Piero della Francesca (c. 1415–1492), De Prospectiva pingendi (On the Perspective of painting), around 1470-80.


An icosahedron in perspective from De Prospectiva pingendi Source: Wikimedia Commons

He never published this work, but his ideas on perspective were incorporated in his book Divina proportione by the mathematician Luca Pacioli (c. 1447–1517), written around 1498 but first published in 1509. Pacioli’s book also plagiarised another manuscript of della Francesca’s on perspective, his De quinque corporibus regularibus (The Five Regular Solids).


Piero della Francesca by Giorgio Vasari Source: Wikimedia Commons

Mathematicians and artists continued over the centuries to write books describing and investigating the geometrical principles of linear perspective the most notable of, which during the Renaissance was Albrecht Dürer’s Underweysung der Messung mit dem Zirckel und Richtscheyt (Instructions for Measuring with Compass and Ruler) published in 1525, which contains the first account of two point perspective. Dürer is credited with introducing linear perspective into the Northern Renaissance.


Dürer, draughtsman Making a Perspective Drawing of a Reclining Woman

Naturalism is, as its name would suggest, the development in art to depict things naturally i.e., as we see them with our own eyes. Linear perspective is actually one aspect of naturalism. In her The Body of the Artisan, Pamala H. Smith writes the following:

It is difficult to know where to begin a discussion of naturalism (which can encompass the striving for “verisimilitude,” “illusionism,” “realism,” and the “imitation of nature”) in the early modern period, for the secondary literature in art history alone is vast. David Summers has defined naturalism as the attempt to make the elements of the artwork (in his account primarily painting) coincide with the elements of the optical experience[2]. (Her endnote: Summers, The Judgement of Sense, p. 3)

Smith also quotes in this context Alberti, “[He] put it in about 1435, making a picture that was an “open window” through which the world was seen.[3]” There is no neat timeline of events for Naturalism, as I have recreated above for linear perspective. Smith gives as her first historical example of Naturalism the so-called Carrara Herbal produced in Padua around 1400, with till then unknown, for this type of literature, unprecedented naturalism in its illustrations.[4]


Violet plant – Carrara Herbal (c.1400), f.94 – BL Egerton MS 2020.jpg Source: Wikimedia Commons

As we will see in a later blog post it was in natural history, in particular in botany, that naturalism made a major impact in printed scientific illustrations.

Although, they still hadn’t really adopted the techniques of linear perspective it was the artists of the Northern Renaissance, rather than their Southern brethren, who first extensively adopted Naturalism, most notably Jan van Eyck (before 1390 – 1441). An attribute of the Naturalism of these painters was the use of mirrors in their paintings to symbolise the reflection of nature or reality.


Jan van Eyck Detail with mirror and signature; Arnolfini Portrait, 1434 Source: Wikimedia Commons

Once again, we meet here Albrecht Dürer, who is justifiably renowned for his lifelike reproduction of various aspects of nature in his artwork.


Albrecht Dürer Young Hare, (1502), Source: Wikimedia Commons


Albrecht Dürer Great Piece of Turf, 1503 Source: Wikimedia commons

It is important to note here that although this picture looks very realistic, when first viewed, it is actually an example of illusion or hyperrealism. There are none of the old or withered plants that such a scene in nature would inevitably have. Also none of the plants obscure other plants with their shadows, as they would in reality. What Dürer delivers up here is an idealised naturalism, almost a contradiction in terms. This conflict between real naturalism and the demands of clear to interpret illustrations would play a significant role in the illustrations of Renaissance books on natural history.

However, as we shall see in later posts both linear perspective and Naturalism made a massive impact on the scientific and technological book illustrations that were produced during the Renaissance.

[1] Vitruvius, Ten Books on Architecture, Eds. Ingrid D. Rowland & Thomas Noble Howe, CUP, 1999 p. 86

[2] Pamala H. Smith, The Body of the Artisan: Art and Experience in the Scientific Revolution, University of Chicago Press, 2004 p. 9

[3] Smith, p. 33

[4] Smith p. 33

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Filed under Book History, History of science, Renaissance Science

Tracking the alchemical gospel through Medieval and Early Modern England

This is going to be yet another of those book reviews where I start by explaining how much the history of science has changed since I first became engaged in it, in my youth. Back in the not so good old days, the so-called occult sciences we not really considered part of the history of science by the mainstream of the discipline. In fact, they were often viewed as somehow dirty and degrading. When it first began to be suggested that Isaac Newton was an alchemist, Rupert Hall, then a leading historian of science, insisted that Newton’s activities had actually been chemistry, motivated by his work as boss of the Royal Mint and definitely not alchemy. I of course, not knowing better, stuck to the mainstream and avoided the occult sciences. Something, I now regard as rather strange given my very active advocacy for the history of astrology if one wishes to understand the history of astronomy.

As far as the history of alchemy is concerned, my eyes were opened by Betty Jo Teeter Dobbs’ The Foundations of Newtons Alchemy, or the Hunting of the Green Lyon (CUP; 1976), which I read with growing amazement and enthusiasm, sometime in the early 1980s. My memory tells me that the book caused a minor sensation in the history of science world, revealing as it did, for the first time with academic rigour, the extent of Newton’s involvement with this distinctly non-scientific discipline. The effect was even greater when Richard Westfall, Newton’s greatest biographer, gave more than tacit support to Dobbs’ views on Newton’s alchemical activities. Alchemy was now a serious subject for historians of science to pursue.

Over the succeeding decades the history of alchemy became an accepted part of the history of science with excellent publications from first class historians such as Bruce Moran, Tara Nummedal, Pamala H. Smith, as well as William R. R. Newman and Lawrence Principe both together and separately. For somebody new to the discipline I can recommend Lawrence Principe’s Secrets of Alchemy (University of Chicago Press, 2013), as an excellent general introduction. William Newman’s newest book is Newton the Alchemist: Science, Enigma, and the Quest for Nature’s Secret Fire (Princeton University Press, 2018). One of the stars of the new generation of historians of alchemy is Jennifer M. Rampling, whose latest book, The Experimental Fire: Inventing English Alchemy 1300–1700[1] is the subject of this book review.


Rampling’s book delivers exactly what the title promises. She takes her reader along the winding path that the study and practice of alchemy took in England from its early establishment during the reign of Edward III (1312–1377) up to end of the seventeenth century, when those stalwart founders of modern science, Robert Boyle and Isaac Newton were practicing alchemists.

Before she takes the reader through four hundred years of English alchemy history, Rampling prefaces the journey with a discussion of the multiple meanings, conflicting and oft contradictory meanings, shifting meanings and evolving meanings of various central alchemical terms, most notably mercury and the stone, as in the philosophers stone. Her careful analysis demonstrates the problems involved in trying to understand alchemical writings, not only for the modern reader or historian but also for the alchemical practitioners throughout history. This chapter also serves as an introduction to the central aspect of the book, what the author calls, ‘practical exegesis’. This is the process by which the practicing alchemists reads, interprets and attempts to convert into practice, the authoritative texts that allude and hint rather than instruct openly and clearly. Throughout her narrative Rampling shows how each generation of English alchemists made great efforts to produce a consistent, at least internally rational reading of the texts and authorities that they are working with.

Rampling distinguishes two main types of practicing alchemists. On the one hand we have the philosophical alchemist, who presents long complex interpretations of the authoritative texts to demonstrate his mastery of the secrets that they contain. Such alchemists oft preferred to avoid the term alchemist referring to themselves as philosophers, or natural philosophers, who rise above the mundane production of gold, although willing, when suitably induced, to do just that. On the other hand, there are the purely practical alchemists, who head straight for the laboratory with a recipe in hand and have little time for the high-flown philosophical speculations of their colleagues. Rampling deals predominantly with those of a philosophical cast.

Readers of this blog will know that I place a lot of emphasis in the history of science on a contextual narrative i.e., under which circumstances did the science in question take place, what were the external forces driving the science and how were the practitioners embedded in their cultural milieu. In this sense Rampling’s in exemplary. Her alchemists do not speculate in thin air devoid of any contact to society in general but are firmly embedded in the cultures of their times.

Rampling’s alchemists are real people, where the sources make this possible and unfortunately the sources are often meagre, she describes their life circumstances, their professions, their non-alchemical activities and their alchemical motivations. Financing was always important for alchemists and Rampling gives in depth analysis of the texts they wrote to attract wealthy, aristocratic and particularly royal sponsors for their alchemical endeavours. How these are formulated is particularly revealing, because for much of the period under discussion alchemy, or at least multiplication i.e., the alchemical production of gold or silver bullion was forbidden by law. On the other had the Crown was perpetually destitute and more than a bit interested in alchemists’ claims to able to covert base metals into gold and silver.

The English alchemy that Rampling traces down the centuries has its roots in the alchemical texts attributed to the Majorcan mathematician, philosopher and logician Ramon Llull (c. 1232–c. 1315). Attributed is here the correct term because none of texts were actually written by the Spanish polymath, which illustrates the common practice of attributing alchemical texts to eminent authors to increase their status. However, the medieval English alchemists believed the fake attribution and worked on understanding and interpreting the pseudo-Lllullian texts.

Having laid the foundations Rampling moves on to George Ripley (c. 1415–1490), who takes up a central position in the book. Ripley is the most important English medieval alchemist and Rampling takes the reader carefully through his main writings, explaining how he interpreted and balanced out the obscurities and contradictions he found in reading the pseudo-Llullian and other writings that informed his practice.


Have laid the basics, Rampling takes us down the years to 1700, showing how successive generations reworked the pseudo-Llullian and Ripleyian texts, creating new contributions to the alchemical canon, often reassigning known texts to new authors to give them more authority.  We learn how Henry VIII’s dissolution of the monasteries led to the loss of large quantities of manuscripts relevant to the study of alchemy making life difficult for the historian. However, Rampling shows how to reconstruct the alchemy of the period using literary archaeology on those texts that are still available.

Moving into the Elizabethan period we meet two new phenomena in the world of alchemy.  The English alchemist produced English translations of Latin texts making them available to a wider audience and at the same time creating a truly English school of alchemy. At the same time the English alchemists had to cope with foreign alchemists coming to their island and competing for the limited sources of sponsorship needed to set up alchemical laboratories and purchase the necessary starting materials.

Although it deals primarily with English alchemy, throughout the book the reader learns quite a lot about the continental developments, as there was, during the whole period, active exchange between the island and the mainland. Ripley is, for example, said to have travelled and studied on the continent the supposed source of much of his alchemical wisdom. The Elizabethan continental alchemists refreshed the English tradition with new continental developments in the discipline.

This exchange reached a high point in the life and work of Edward Kelley (1555–1597/8), who, better known as the scryer who mediated John Dee’s conversations with angels, was in his later life an acclaimed alchemist on the European mainland. Kelley originally travelled to Prague with Dee to try and find favour with the Holy Roman Emperor, Rudolf II, who was the biggest supporter and sponsor of the occult sciences in the whole of Europe. Dee failed to find favour on the continent and returned disappointed to England whereas Kelley remained and established himself as a leading alchemical authority. Rampling takes us skilfully through the twists and turns, and ups and downs of Kelley’s late career and yet another reworking of the pseudo-Llullian-Ripleyian canon, which found favour amongst continental practitioners


As is now well known to Newton scholars, alchemy didn’t disappear with the advent of the so-called scientific revolution but was still strong in England in the seventeenth century, with Newton, Boyle and Locke all practitioners. Here Rampling takes us through the work of figures such as Elias Ashmole (1617–1692), who created large collections of alchemical manuscripts and books in the final phase of English alchemy.

Rampling’s extensive survey of English alchemy is a masterclass in history of science research and serves as a model for anyone who wishes to undertake such a project. Although it meets the highest standards of academic research, she writes with a light touch and an accomplished literary style making a complex and technical topic accessible to the not necessarily specialist reader. The book is illustrated with grey in grey prints and, hallelujah, it has very extensive, high informative footnotes (not endnotes!). There is a wide-ranging bibliography of both primary and secondary sources and a comprehensive index.

The Experimental Fire is probably not recommended as an introductory text for somebody completely new to the history of alchemy, they should perhaps read Principe’s Secrets of Alchemy before attempting to tackle Rampling’s more advanced text. However, anybody with some basic knowledge of the history of alchemy, and an interest in developing that knowledge, could and should read her book. For those with a serious interest in the topic The Experimental Fire is an obligatory read and must already be considered a standard work in the genre.

[1] Jennifer M. Rampling, The Experimental Fire: Inventing English Alchemy 1300–1700, University of Chicago Press, Chicago and London, 2020.


Filed under History of Alchemy, History of science

Renaissance Science – V

According to the title, this series is supposed to be about Renaissance science but as we saw in the last episode the Renaissance started off as anything but scientific, so what exactly is Renaissance science, does it even exist, and does it actually have anything to do with the language and linguistics movement that kicked of the period that is now known as the Renaissance? I will start with the second of these questions and return later to the other two.

The history of science in its present form is actually a very young discipline, which really only came to fruition in the twentieth century. There are of course early elements of the discipline scattered around the past but the structured academic discipline as we know it only really began in the decades between the two world wars and came to maturity following the second world war. The early discipline was of course very euro-centric, and a major element was the so-called scientific revolution, which was initially seen as a single historical block. Maria Boas Hall (1919–2009) was, as far as I know, the first to divide that block into two parts, a sort of proto scientific revolution, her The Scientific Renaissance 1450–1630 (published, 1962), followed by the full scientific revolution. She was followed in this bifurcation by Peter Dear in his book Revolutionizing the Sciences: European Knowledge in Transition 1500–1700 (originally 2001, 3rd ed. 2019), who sees two phases, 1500-1600 and 1600-1700. These two books established, I think correctly, the idea of a separate Scientific Renaissance, which preceded the Scientific Revolution.

So, what is the nature of this Renaissance science, how did it differ from the existing medieval science and what changed and when going forward into the so-called scientific revolution? There is quite a lot to unpack here and the first thing we need to do is to stop talking about science and instead talk about knowledge, the more correct translation of the Latin term, scientia used in this period. Also, within the scope of scientia, what we might regard as the areas of hard science, which Aristotle called physics, meaning the study of nature, should more appropriately be referred to as natural philosophy. However, medieval natural philosophy was a very restricted area, it included cosmology but did not for example include astronomy, which was a mathematical discipline. Aristotle rejected mathematics as scientia, because its objects were not real. The mathematical disciplines, such as astronomy and optics, were not regarded as belonging to natural philosophy but were given a sort of halfway status. Natural philosophy also didn’t include any of what we would now call the life sciences.

Knowledge in the European medieval context was divided into two completely distinct areas, which didn’t intersect in anyway. On the one side there was the knowledge propagated by the medieval universities, which, as I explained in an earlier post, was almost totally theoretical book knowledge, with almost no practical aspects to it at all. This knowledge was not static, as it is often falsely presented, but evolved over time. However, this evolution was also a theoretical process. The knowledge progressed through debate and the application of argumentation and logic, not through the acquisition of new empirical facts.

The other area of knowledge was artisanal knowledge, that is the knowledge of the maker, the craftsman. This knowledge was empirical and practical, consisting of directions or instruction on how to complete a given task, how to achieve a given aim or fulfil a given assignment. It might, for example, be how to make bricks out of clay, or how to build a stone arch that would be stable and not collapse under load. This knowledge covered a vast range of activities and had been accumulated from a very wide range of sources over virtually the whole of human existence. This knowledge was, traditional, rarely written down but was usually passed on by word of mouth and direct training from master to apprentice, often from father to son over many generations. This knowledge was in general not viewed as knowledge by scholars within the university system.

Starting around fourteen hundred a process of what we would today call crossover began between these two previously distinct and separate areas of knowledge. Scholars began to write learned works about specific areas of artisanal knowledge, a classic example being Georgius Agricola’s De re metallica, published posthumously in 1556, and craftsmen began to write books explaining and elucidating their forms of knowledge, for example the goldsmith Lorenzo Ghiberti’s I commentarii, which remained unfinished in manuscript and unpublished at the time of his death in 1455. It should be noted that before the Renaissance the people we now call artists were regarded as craftsmen. Crossover is here perhaps the wrong term, as people didn’t just cross the boundary in both directions but the boundary itself began to dissolve producing a meld between the two types of knowledge that would over the next two and a half centuries lead to the modern concept of knowledge or science.

What provoked this move towards practical, empirical knowledge during the Renaissance? There are two major areas of development driving this shift in emphasis, as to what constitutes knowledge. The first is general social, political, economical and cultural developments. The rapid increase in long distant trade produced a demand for new methods of navigation and cartography. Changes in concepts of land ownership also drove developments in cartography and the closely associated surveying. Developments in warfare again drove developments in cartography but also in gunnery, a new discipline, and military tactics in general. The invention of gunpowder and with-it military gunnery drove developments in metallurgy, as did other areas where the use of metals increased, for example in the wider use of metal coinage. The greater demand for metals in turn drove the development of mining. Greater wealth in society in general and the perceived need for rulers to display their power through ostentatious display increased the demand for architecture and fine art. The introduction of gunpowder and gunnery also drove the development of architecture because of the need for better defences. These are just some examples of the growing demand for artisanal knowledge within an increasingly urban culture financed by long distance trade.

But what of the movement that gave the Renaissance its name, which we saw was initially language and linguistic based movement, how did this play a role in this move towards the elevation of the status of empirical and practical knowledge if at all? This is in fact our second area of development. Those early Renaissance scholars, who searched for Latin literature texts and orations in the monastic libraries also unearthed Greek and Latin texts on science, technology, mathematics and medicine and in the general renewal of the culture of antiquity also translated and made these texts available, often arguing for their purity in comparison to the texts from the same authors that had come into Europe through the filter of translation into Arabic and then back into Latin. Example of texts that became available for the first time are Vitruvius’ work on architecture De architectura and Ptolemaeus’ Geographia. The latter had been known to the Islamic cartographers but had not been translated into Latin from Arabic during the twelfth century translation movement. As well as bringing new original Greek and Latin manuscripts into circulation the Renaissance scholars introduced a strong empirical element through their philological work. This work was based on an empirical analysis of various copies of a given work as well as an investigation of the plausibility of a given word, phrase or sentence, which didn’t appear to make sense. Beyond this in some areas the Renaissance scholars, as we shall see in more detail later, began to try and understand what the scholars were referring to in specific instances. For example, which plants was Dioscorides referring to in his De meteria medica? The answer to such questions required real empirical research.

The Renaissance opened up a whole new world of practical, empirical knowledge alongside the theoretical book knowledge of the medieval university. The last question is how did this differ from the knowledge of the following period and when did this transition take place?

The emphasis on this Renaissance empirical knowledge was very much on the practical. How can we use it, where and how can it be applied? During the seventeenth century the emphasis changed to one of devising theoretical explanations for all of the freshly won empirical knowledge from the previous two hundred years. The transition is from how do we use or apply it, to how do we explain it. It is impossible to set a firm date for this transition as it was by its very nature a gradual one, so both Boas Hall and Dear are in a certain sense correct with their respective 1630 and 1600. The transition had definitely already begun by 1600 and probably wasn’t finished, yet by 1630. In my case I follow Francis Yates in choosing the end of the Thirty Year’s War in 1648, as I think the transition had been completed by then at the latest.


Filed under History of Cartography, History of Navigation, History of science, Renaissance Science

A flawed survey of science and the occult in the Early Modern Period

There is no shortage of good literature on the relationships between science and magic, or science and astrology, or science and alchemy during the Early Modern Period so what is new in Mark A. Waddell’s Magic, Science, and Religion in Early Modern Europe[1]? Nothing, because it is not Waddell’s aim to bring something new to this material but rather to present an introductory textbook on the theme aimed at university students. He sets out to demonstrate to the uninitiated how the seemingly contradictory regions of science, religion and magic existed in the Early Modern Period not just parallel to but interwoven and integrated with each other.  Waddell’s conception is a worthy one and would make for a positive addition to the literature, his book is however flawed in its execution.


Image with thanks from Brian Clegg

The book actually starts well, and our author sets out his planned journey in a lengthy but clear and informative introduction. The book itself is divided into clear sections each dealing with a different aspect of the central theme. The first section deals with the Renaissance discoveries of hermeticism and the cabala and the concept of natural magic, as a force to manipulate nature, as opposed to demonic magic. Although limited by its brevity, it provides a reasonable introduction to the topics dealt with. My only criticisms concerns, the usual presentation of John Dee as a magus, whilst downplaying his role as a mathematician, although this does get mentioned in passing. However, Waddell can’t resist suggesting that Dee was the role model for Marlowe’s Faustus, whereas Faustus is almost certainly modelled on Historia von D. Johann Faustus, a German book containing legends about the real Johann Georg Faust (c. 1480–c. 1541) a German itinerant alchemist, astrologer, and magician of the German Renaissance. A note for authors, not just for Waddell, Dee in by no means the only Renaissance magus and is not the role model for all the literary ones.

Waddell’s second section deals with demonic magic, that is magic thought to draw its power from communion with the Devil and other lesser demons. As far as I can tell this was the section that most interested our author whilst writing his book. He manages to present a clear and informative picture of the period of the European witch craze and the associated witch hunts. He deals really well with the interrelationship between the belief in demonic witchcraft and the Church and formal religion. How the Church created, propagated and increasingly expanded the belief in demonic magic and witches and how this became centred on the concept of heresy. Communion with the devil, which became the central theme of the witch hunts being in and of itself heretical.

Following this excellent ´section the book starts to go downhill. The third section of the book deals with magic, medicine and the microcosm. Compared with the good presentation of the previous section I can only call this one a mishmash. We get a standard brief introduction to medieval academic medicine, which Waddell labels premodern, with Hippocrates, Galen and a nod to Islamic medical writes, but with only Ibn Sīnā mentioned by name. This is followed by a brief description of the principles of humoral medicine. Waddell correctly points out the academic or learned doctors only represent one group offering medical assistance during this period and gives a couple of lines to the barber-surgeons. It is now that the quality of Waddell’s presentation takes a steep nosedive.

Having correctly pointed out that medieval academic medicine was largely theoretical he then, unfortunately, follows the myth of “and then came Andy”! That is, we jump straight into Andreas Vesalius and his De fabrica, as I quote, “the beginnings of what we would understand as a rigorous and empirical approach to the study of anatomy.” Strange, only two weeks ago I wrote a post pointing out that Vesalius didn’t emerge out of the blue with scalpel raised high but was one step, albeit a very major one, in a two-hundred-year evolution in the study of anatomy. Of course, Waddell dishes up the usual myth about how seldom dissection was before Vesalius and corpses to dissect were rare etc, etc. Whereas, in fact, dissection had become a regular feature of medical teaching at the European universities over that, previously mentioned two-hundred-year period. Waddell closes his Vesalius hagiography with the comment that Vesalius’ De fabrica “was a crucial step in the more widespread reform of medical theory and practice that took place over the next 150 years” and although his book goes up to the middle of the eighteenth century, we don’t get any more information on those reforms. One of his final comments on Vesalius perpetuates another hoary old myth. He writes, “Vesalius made it permissible to question the legacy of antiquity and, in some cases, to overturn ideas that had persisted for many hundred years.” Contrary to the image created here, people had been challenging the legacy of antiquity and overturning ideas since antiquity, as Edward Grant put it so wonderfully, medieval Aristotelian philosophy was not Aristotle’s philosophy. The same applies to all branches of knowledge inherited form antiquity.

Having dealt with Vesalius, Waddell moves on to the philosophy of microcosm-macrocosm and astro-medicine or as it was called iatromathematics, that is the application of astrology to medicine. His basic introduction to the microcosm-macrocosm theory is quite reasonable and he then moves onto astrology. He insists on explaining that, in his opinion, astrology is not a science but a system of non-scientific rules. This is all well and good but for the people he is dealing with in the Early Modern Period astrology was a science. We then get a guide to astrology for beginners which manages right from the start to make some elementary mistakes. He writes, “You might know what your “sign” is, based on when you were born […]. These refer to the twelve (or according to some, thirteen) signs of the Western zodiac, which is the band of constellations through which the Sun appears to move over the course of a year.” The bullshit with thirteen constellations was something dreamed up by some modern astronomers, who obviously know nothing about astrology, its history or the history of their own discipline for that matter, in order to discredit astrology and astrologers. The only people they discredited were themselves. The zodiac as originally conceived by the Babylonians a couple of millennia BCE, mapped the ecliptic, the apparent annual path of the Sun around the Earth, using seventeen constellations. These were gradually pared down over the centuries until the Western zodiac became defined around the fifth century BCE as twelve equal division of the ecliptic, that is each of thirty degrees, starting at the vernal or spring equinox and preceding clockwise around the ecliptic. The most important point is that these divisions, the “signs”, are not constellations. There are, perhaps unfortunately, named after the constellations that occupied those positions on the ecliptic a couple of millennia in the past but no longer do so because of the precession of the equinoxes.

Although, Waddell gives a reasonable account of the basics of astro-medicine and also how it was integrated with humoral medicine but then fails again when describing its actual application. A couple of examples:

There were cases of surgeons refusing to operate on a specific part of the body unless the heavens were aligned with the corresponding zodiac sign, and it was not uncommon for learned physicians to cast their patient’s horoscope as part of their diagnosis.


Though the use of astrology in premodern medicine was common, it is less clear how often physicians would have turned to astrological magic in order to treat patients. Some would have regarded it with suspicion and relied instead on genitures alone to dictate their treatment, using a patient’s horoscope as a kind of diagnostic tool that provided useful information about that person’s temperament and other influences on their health. Astrological magic was a different thing altogether, requiring the practitioner to harness the unseen forces and emanations of the planets to heal their patient rather than relying solely on a standard regimen of care.

This is a book about the interrelationships between magic, religion and science during the Early Modern period, but Waddell’s lukewarm statements here, “there were cases of surgeons refusing to operate…, not uncommon for learned physicians…” fail totally to capture the extent of astro-medicine and its almost total dominance of academic medicine during the Renaissance. Beginning in the early fifteenth century European universities established the first dedicated chairs for mathematics, with the specific assignment to teach astrology to medical students.

During the main period of astrological medicine, the most commonly produced printed products were wall and pocket calendars, in fact, Gutenberg printed a wall calendar long before his more famous Bible. These calendars were astronomical, astrological, medical calendars, which contained the astronomical-astrological data that enabled physicians and barber-surgeons to know when they should or should not apply a particular treatment. These calendars were universal, and towns, cities and districts appointed official calendar makers to produce new calendars, every year. Almost no physician or barber-surgeon would consider applying a treatment at an inappropriate time, not as Waddell says, “cases of surgeons refusing to operate.” Also, no learned physicians in this time would begin an examination without casting the patient’s horoscope, to determine the cause, course and cure for the existing affliction. The use of what Waddell calls astrological magic, by which he means astrological talismans, by learned physicians was almost non-existent. This is aa completely different area of both astrology and of medicine.

Within the context of the book, it is obvious that we now turn to Paracelsus. Here Waddell repeats the myth about the name Paracelsus, “The name by which he is best known, Paracelsus, is something of a mystery, but historians believe that it was inspired by the classical Roman medical writer Celsus (c. 25 BCE–c. 50 CE). The prefix “para-“ that he added to that ancient name has multiple meanings in Latin, including “beyond,” leading some to speculate that this was a not-so-modest attempt to claim a knowledge of medicine greater than that of Celsus.” This is once again almost certainly a myth. Nowhere in his voluminous writings does Paracelsus mention Celsus and there is no evidence that he even knew of his existence. Paracelsus is almost certainly a toponym for Hohenheim meaning ‘up high’, Hohenheim being German for high home. By the way, he only initially adopted Paracelsus for his alchemical writings. The rest of his account of Paracelsus is OK but fails to really come to grips with Paracelsus’ alchemy.

To close out his section on medicine, Waddell now brings a long digression on the history of the believe in weapon salve, a substance that supposedly cured wounds when smeared on the weapon that caused them, an interesting example of the intersection between magic and medicine. However, he misses the wonderful case of a crossover into science when Kenhelm Digby suggested that weapon salve could be used to determine longitude.


The next section A New Cosmos: Copernicus, Galileo, and the Motion of the Earth, takes us into, from my point of view, a true disaster area:

In this chapter, we explore how the European understanding of the cosmos changed in the sixteenth and seventeenth centuries. It was on the single greatest intellectual disruptions in European history, and in some ways we are still feeling its effects now, more than 450 years later. The claim that our universe was fundamentally different from what people had known for thousands of years led to a serious conflict between different sources of knowledge and forms of authority, and forced premodern Europe to grapple with a crucial question: Who has the right to define the nature of reality?

This particular conflict is often framed by historians and other commentators as a battle between science and religion in which the brave and progressive pioneers of the heliocentric cosmos were attacked unjustly by a tyrannical and old-fashioned Church. This is an exaggeration, but not by much. [my emphasis]

Waddell starts with a standard account of Aristotelian philosophy and cosmology, in which he like most other people exaggerates the continuity of Aristotle’s influence. This is followed by the usual astronomers only saved the phenomena story and an introduction to Ptolemy. Again, the continuity of his model is, as usual, exaggerated. Waddell briefly introduces the Aristotelian theory of the crystalline spheres and claims that it contradicted Ptolemy’s epicycle and deferent model, which is simply not true as Ptolemy combined them in his Planetary Hypothesis. The contradiction between the two models is between Aristotle’s astronomical mathematical homocentric spheres used to explain the moments of the planets (which Waddell doesn’t mention), which were imbedded in the crystalline spheres, and the epicycle-deferent model. Waddell then hypothesises a conflict between the Aristotelian and Ptolemaic system, which simply didn’t exist for the majority, people accepting a melange of Aristotle’s cosmology and Ptolemy’s astronomy. There were however over the centuries local revivals of Aristotle’s homocentric theory.

Now Copernicus enters stage right:

Copernicus had strong ties to the Catholic Church; he was a canon, which meant he was responsible for maintaining a cathedral (the seat of a bishop or archbishop), and some historians believe he was ordained as a priest as well.

If a student writes “some historians” in a paper they normally get their head torn off by their teachers. Which historians? Name them! In fact, I think Waddell would have a difficult time naming his “some historians”, as all the historians of astronomy that I know of, who have studied the question, say quite categorically that there is no evidence that Copernicus was ever ordained. Waddell delivers up next:

Most probably it [De revolutionibus] was completed by the mid-1530s, but Copernicus was reluctant to publish it right away because his work called into question some of the most fundamental assumptions about the universe held at the time.

It is now generally accepted that Copernicus didn’t published because he couldn’t provide any proofs for his heliocentric hypothesis. Waddell:

He did decide to circulate his ideas quietly among astronomers, however, and after seeing his calculations were not rejected outright Copernicus finally had his work printed in Nuremberg shortly before his death.

Here Waddell is obviously confusing Copernicus’ Commentariolus, circulated around 1510 and  Rheticus’ Narratio prima, published in two editions in Danzig and Basel, which I wouldn’t describe as circulated quietly. Also, neither book contained  calculations. Waddell now tries to push the gospel that nobody really read the cosmological part of De revolutionibus and were only interested in the mathematics. Whilst it is true that more astronomers were interested in the mathematical model, there was a complex and intensive discussion of the cosmology throughout the second half of the sixteenth century. Waddell also wants his reader to believe that Copernicus didn’t regard his model as a real model of the cosmos, sorry this is simply false. Copernicus very definitely believed his model was a real model.

 Moving on to Tycho Brahe and the geo-heliocentric system Waddell tells us that, “[Tycho] could not embrace a cosmology that so obviously conflicted with the Bible. It is not surprising, then, that the Tychonic system was adopted in the years following Brahe’s death in 1601”

At no point does Waddell acknowledge the historical fact that also the majority of astronomers in the early decades of the seventeenth century accepted a Tychonic system because it was the one that best fit the known empirical facts. This doesn’t fit his hagiographical account of Galileo vs the Church, which is still to come.

Next up Waddell presents Kepler and his Mysterium Cosmographicum and seems to think that Kepler’s importance lies in the fact that he was ac deeply religious and pious person embraced a heliocentric cosmos. We then get an absolute humdinger of a statement:

There is more that could be said about Kepler, including the fact that he improved upon the work of Copernicus by proposing three laws of planetary motion that are still taught in schools today. For the purpose of this chapter, however, Kepler is significant as someone who embraced heliocentricity and [emphasis in the original] faith.

With this statement Waddell disqualifies himself on the subject of the seventeenth century transition from a geocentric cosmos to a heliocentric one. Kepler didn’t propose his three laws he derived them empirically from Tycho’s observational data and they represent the single most important step in that transition.

We now have another Waddell and then came moment, this time with Galileo. We get a gabled version of Galileo’s vita with many minor inaccuracies, which I won’t deal with here because there is much worse to come. After a standard story of the introduction of the telescope and of Galileo’s improved model we get the following:

[Galileo] presented his device to the Doge (the highest official in Venice) and secured a truly impressive salary for life from the Venetian state. Mere weeks later he received word from the court of the Medici in Galileo’s home in Tuscany, that they wanted a telescope of their own. The Venetian leaders, however had ordered Galileo to keep his improved telescope a secret, to be manufactured only for Venetian use, and Galileo obliged, at least temporarily.

When they bought Galileo’s telescope they thought, erroneously, that they were getting exclusive use of a spectacular new instrument. However, it soon became very clear that telescopes were not particularly difficult to make and were freely available in almost all major European towns. They were more than slightly pissed off at the good Galileo but did not renege on their deal. The Medici court did not request a telescope of their own, but Galileo in his campaign to gain favour by the Medici, presented them with one and actually travelled to Florence to demonstrate it for them. We now move on to the telescopic discoveries in which Waddell exaggerates the discovery of the Jupiter moons. We skip over the Sidereus Nuncius and Galileo’s appointment as court philosophicus and mathematicus in Florence, which Waddell retells fairly accurately. Waddell now delivers up what he sees as the great coup:

The problem was that the moons of Jupiter, while important, did not prove the existence of a heliocentric cosmos. Galileo kept searching until he found something that did: the phases of Venus.

The discovery of the phases of Venus do indeed sound the death nell for a pure geocentric system à la Ptolemy but not for a Capellan geo-heliocentric system, popular throughout the Middle Ages, where Mercury and Venus orbit the Sun, which orbits the Earth, or a full Tychonic system with all five planets orbiting the Sun, which together with the Moon orbits the Earth. Neither here nor anywhere else does Waddell handle the Tychonic system, which on scientific, empirical grounds became the most favoured system in the early decades of the seventeenth century.

We then get Castelli getting into deep water with the Grand Duchess Christina and, according to Waddell, Galileo’s Letter to the Grand Duchess Christina. He never mentions the Letter to Castelli, of which the Letter to the Grand Duchess Christina was a later extended and improved version, although it was the Letter to Castelli, which got passed on to the Inquisition and caused Galileo’s problems in 1615. Waddell tells us:

In 1616 the Inquisition declared that heliocentrism was a formal heresy.

In fact, the eleven Qualifiers appointed by the Pope to investigate the status of the heliocentric theory delivered the following verdict:

( i ) The sun is the centre of the universe (“mundi”) and absolutely immobile in local motion.

( ii ) The earth is not the centre of the universe (“mundi”); it is not immobile but turns on itself with a diurnal movement.

All unanimously censure the first proposition as “foolish, absurd in philosophy [i.e. scientifically untenable] and formally heretical on the grounds of expressly contradicting the statements of Holy Scripture in many places according to the proper meaning of the words, the common exposition and the understanding of the Holy Fathers and learned theologians”; the second proposition they unanimously censured as likewise “absurd in philosophy” and theologically “at least erroneous in faith”.

However, the Qualifiers verdict was only advisory and the Pope alone can official name something a heresy and no Pope ever did.

Waddell gives a fairly standard account of Galileo’s meeting with Cardinal Roberto Bellarmino in 1616 and moves fairly rapidly to the Dialogo and Galileo’s trial by the Inquisition in 1633. However, on the judgement of that trial he delivers up this gem:

Ultimately, Galileo was found “vehemently suspect of heresy,” which marked his crime as far more serious than typical, run-of-the-mill heresy.

One really should take time to savour this inanity. The first time I read it, I went back and read it again, because I didn’t think anybody could write anything that stupid. and that I must have somehow misread it. But no, the sentence on page 131 of the book reads exactly as I have reproduced it here. Maybe I’m ignorant, but I never knew that to be suspected of a crime was actually “far more serious” than actually being found guilty of the same crime. One of my acquaintances, an excellent medieval historian and an expert for medieval astronomy asked, “WTF is run-of-the-mill heresy?” I’m afraid I can’t answer her excellent question, as I am as perplexed by the expression, as she obviously is.

Enough of the sarcasm, the complete sentence is, of course, total bollocks from beginning to end. Being found guilty of suspicion of heresy, vehement or not, is a much milder judgement than being found guilty of heresy. If Galileo had been found guilty of heresy, there is a very good chance he would have been sentenced to death. The expression “run-of-the-mill heresy” is quite simple total balderdash and should never, ever appear in any academic work.

Waddell now draws his conclusions for this section, and they are totally skewed because he has simple ignored, or better said deliberately supressed a large and significant part of the story. In the final part of this section, “Science versus Religion?”, he argues that the Church was defending its right to traditional truth against Galileo’s scientific truth. He writes:

This was not a fight between winners and losers, or between “right” and “wrong.” Instead, this is a story about power, tradition, and authority, about who gets to decide what is true and on what grounds.


Organised religion, exemplified here by the Catholic Church, had an interest in preserving the status quo [emphasis in original] for many reasons, some of which were undeniably self-serving.


The ideas of Aristotle and Ptolemy were still taught in virtually every European university well into the seventeenth century, making the Church’s allegiance to these ideas understandable. At the same time, the Church also recognised another source of authority, the Christian scriptures, which stated clearly that the Earth did not move. On both philosophical and theological grounds, then, the Church’s position on the immobility of the Earth was reasonable by the standards of the time.  

The above quotes have more relationship to a fairy tale than to the actual historical situation. Due to the astronomical discoveries made since about 1570, by1630 the Catholic Church had abandoned most of the Aristotelian cosmology and never adopted  Aristotelian astronomy. They fully accepted that the phases of Venus, almost certainly observed by the Jesuit astronomers of the Collegio Romano before Galileo did, refuted the Ptolemaic geocentric astronomy. Instead by 1620 the Church had officially adopted the Tychonic geo-heliocentric astronomy, not, as Waddell claims, on religious grounds but because it best fit the known empirical facts. Despite efforts since 1543, when Copernicus published De revolutionibus, nobody, not even Galileo, who had tried really hard, had succeeded in finding any empirical evidence to show that the Earth moves. Waddell’s attempt to portrait the Church as at best non-scientific or even anti.scientific completely ignores the fact that Jesuit and Jesuit educated mathematicians and astronomer were amongst the best throughout the seventeenth century. They made significant contributions to the development of modern astronomy before the invention of the telescope, during Galileo’s active period, in fact it was the Jesuits who provided the necessary scientific confirmation of Galileo’s telescopic discoveries, and all the way up to Newton’s Principia. Their record can hardly be described as anti-scientific.

The Church’s real position is best summed up by Roberto Bellarmino in his 1615 letter to Foscarini, which is also addressed to Galileo:

Third, I say that if there were a true demonstration that the sun is at the centre of the world and the earth in the third heaven, and that the sun does not circle the earth but the earth circles the sun, then one would have to proceed with great care in explaining the Scriptures that appear contrary; and say rather that we do not understand them than that what is demonstrated is false. But I will not believe that there is such a demonstration, until it is shown me. 

Put simple prove your theory and we the Church will then reinterpret the Bible as necessary, which they in fact did in the eighteenth century following Bradley’s first proof that the Earth does actually move.

Waddell then goes off on a long presentist defence of Galileo’s wish to separate natural philosophy and theology, which is all well and good but has very little relevance for the actual historical situation. But as already stated, Waddell is wrong to claim that the phases of Venus prove heliocentrism. Worse than this Galileo’s Dialogo is a con. In the 1630s the two chief world systems were not Ptolemy and Copernicus, the first refuted and the second with its epicycle-deferent models, which Galileo continues to propagate, abandoned, but the Tychonic system and Kepler’s ecliptical astronomy, which Waddell like Galileo simply chose to ignore.

One last comment before I move on. Somewhere Waddell claims that Galileo was the first to claim that the Copernicus’ heliocentric model represented reality rather than simply saving the phenomena. This is historically not correct, Copernicus, Tycho and Kepler all believed that their models represented reality and by 1615, when Galileo first came into confrontation with the Church it had become the norm under astronomers that they were trying to find a real model and not saving the phenomena.

Waddell’s account of the early period of the emergence of modern astronomy sails majestically past the current historical stand of our knowledge of this phase of astronomical history and could have been written some time in the first half of the twentieth century but should not be in a textbook for students in the year 2021.

With the next section we return to some semblance of serious state-of-the-art history. Waddell presents and contrasts the mechanical philosophies of Pierre Gassendi and René Descartes and their differing strategies to include their God within those philosophies. All pretty standard stuff reasonably well presented. The section closes with a brief, maybe too brief, discourse on Joseph Glanvill’s attempts to keep awareness of the supernatural alive against the rationalism of the emerging modern science.

The penultimate section deals with the transition from the Aristotelian concept of an experience-based explanation of the world to one based on experiments and the problems involved in conforming the truth of experimental results. In my opinion he, like most people, gives far too much attention/credit to Francis Bacon but that is mainstream opinion so I can’t really fault him for doing so. I can, however, fault him for presenting Bacon’s approach as something new and original, whereas Bacon was merely collating what had been widespread scientific practice for about two centuries before he wrote his main treatises. Specialist historians have been making this public for quite some time now and textbooks, like the one Waddell has written, should reflect these advances in our historical awareness.

Waddell moves on to alchemy as another source of experimentation that influenced the move to an experiment-based science in the seventeenth century. To be honest I found his brief account of alchemy as somewhat garbled and meandering, basically in need of a good editor. He makes one error, which I found illuminating, he writes:

Aristotle in particular had taught that all metals were composed of two principles: Mercury and Sulphur

Aristotle thought that metals were composed of two exhalations, one is dry and smoky, the other wet and steamy. These first became widely labeled as Mercury and Sulphur in the ninth century writings of the Arabic alchemist Jābir ibn-Hayyān, who took it from the mid-ninth century work, the Book of the Secrets of Creation by Balīnūs. I find this illuminating because I don’t know things like this off by heart, I just knew that Mercury-Sulphur was not from Aristotle, and so have to look them up. To do so I turned to Principe’s The Secrets of Alchemy. Now, according to Waddell’s bibliographical essays at the end of the book, Principe is his main source for the history of alchemy, which means he read the same paragraph as I did and decided to shorten it thus producing a fake historical statement. When writing history facts and details matter!

Having introduced alchemy we now, of course, get Isaac Newton. Waddell points out that Newton is hailed as the epitome of the modern scientist, whereas in fact he was a passionate exponent of alchemy and devoted vast amounts of time and effort to his heterodox religious studies. The only thing that I have to criticise here is that Waddell allocates Newton and his Principia to the mechanical philosophy, whereas his strongest critics pointed out that gravity is an occult force and is anything but conform with the mechanical philosophy. Waddell makes no mention of this here but strangely, as we will see does so indirectly later.

The final section of the book is a discussion of the enlightenment, which I found quite good.  Waddell points out that many assessments of the enlightenment and what supposedly took place are contradicted by the historical facts of what actually happened in the eighteenth century.

Waddell draws to a close with a five-page conclusion that rather strangely suddenly introduces new material that is not in the main text of the book, such as Leibniz’s criticism that Newton’s theory of gravity is not mechanical. It is in fact more a collection of after thoughts than a conclusion.

The book ends with a brief but quite extensive bibliographical essay for each section of the book, and it was here that I think I found the reason for the very poor quality of the A New Cosmos section, he writes at the very beginning:

Two important studies on premodern astronomy and the changes it experienced in early modern Europe are Arthur Koestler’s The Sleepwalkers: A History of Man’s Changing Vision of the Universe (Penguin Books, 1990) and Thomas Kuhn’s The Copernican Revolution: Planetary Astronomy in the Development of Western Thought (Harvard University Press, 1992)

The Sleepwalkers was originally published in 1959 and The Copernican Revolution in 1957, both are horribly outdated and historically wildly inaccurate and should never be recommended to students in this day and age.

All together Waddell’s tome  has the makings of a good and potentially useful textbook for students on an important set of themes but it is in my opinion it is spoilt by some sloppy errors and a truly bad section on the history of astronomy in the early modern period and the conflict between Galileo and the Catholic Church.

[1] Mark A. Waddell, Magic, Science, and Religion in Early Modern Europe, Cambridge University Press, Cambridge & London, 2021


Filed under Book Reviews, History of Alchemy, History of Astrology, History of Astronomy, History of medicine, History of science, Renaissance Science

To simplify is to falsify; falsification is used to simplify

The past is not neat and orderly, divided up into handy segments that the historian can parcel up and deliver to his expectant readers. The past is a horribly complex, tangled up mess. If the past were string, it would not be a neatly rolled up ball but a labyrinthine, knotted heap with multiple ends sticking out all over the place, some seeming to promise a swift unravelling, others apparently leading nowhere. It is the task of the historian to attempt to unravel than unruly heap of twine and try to reconstruct a picture of an episode, a period, or a process that took place at a particular point or during a passage of time in the past. Some of those lose ends represent fragments of the past that have got lost, as we never have anything like a complete record of the past. Unfortunately, teachers, popularisers, journalists and even some historians simply take a pair of scissors and cut out a segment from the heap, simply ignoring any connections that they thus destroy, trim off any lose ends than don’t fit the picture that they want to present, and then serve this up as history. What they end up with is a nice simple, dare I say clean cut, historical picture which they have falsified through their actions. They are not doing history but rather creating myths. I will try to illustrate this procedure by sketching couple of examples.

It will surprise nobody, who follows this blog that my first example is the conflict between Galileo Galilei and the Catholic Church. In the popular version this is inevitably presented as a conflict between science and religion. Galileo championed heliocentricity a valid scientific theory, which however, was in conflict to Holy Scripture and so the Church punished him, at the same time banning the heliocentric theory. You can find versions of this all over the place but almost all of the details are actually false.


Galileo Galilei, portrait by Domenico Tintoretto Source: Wikimedia Commons

Galileo did, indeed, champion heliocentricity, but, at the time he did so, it was merely an unconfirmed hypothesis and not a validated scientific theory. At that time, around 1615 when the conflict started, the empirical evidence tended to support a competing Tychonic geo-heliocentric model, which either gets simply ignored in the simplified version of the story or dismissed out of hand, because! He came into conflict with the Church not because of his support of heliocentricity, but because in his Letter to Castelli he, a mere mathematicus, had the audacity to tell the theologians how to interpret Holy Scripture. To exacerbate the situation the Carmelite theologian Paolo Antonio Foscarini (c. 1565–1616) did the same thing at the same time. This almost never gets mentioned in the popular version and if mentioned only to say have clever his criticism was. What definitely never gets mentioned is that this was in the middle of the Reformation/Counter Reformation, a major religious dispute over, who has the right to interpret Holy Scripture. Galileo couldn’t have picked a worse time to stick his oar in. What we have here at the core is a religious dispute that only indirectly has to do with science.

 Just in this brief sketch we can see that the popular simplified version sails majestically past the historical truth. The final point that gets completely ignored in the popular versions, in fact the propagators almost always claim the opposite, is that the Church did not ban heliocentricity. It said it was fine to discuss heliocentricity as a hypothesis but not as a validated scientific theory, which was its actual scientific status at the time. Despite the fact that it is almost completely false the simplified version gets trotted out by somebody almost daily.

For our second example we take a look at the world of Early Modern medicine and the work of Andries van Wezel (1514–1564) better known as Andreas Vesalius, with a glance to the side in passing at the anatomical studies of Leonardo da Vinci. Vesalius gets trotted out a lot in popular versions of the history of science because, by coincidence, his anatomy book, De humani corporis fabrica libri septem, was published in 1543, the same year as Copernicus’ De revolutionibus, providing a good excuse to call 1543 the beginning of the scientific revolution.


Vesalius Fabrica fronticepiece Source: Wikimedia Commons

Very often Vesalius get presented as the first physician to dissect corpses since antiquity. The claim of being first is also attributed to Leonardo. It is in both cases completely false, as is also the claim that the Church forbid dissection of human corpses and Leonardo or Vesalius were forced to do this secretly, also often stated in both cases. I will briefly deal with Leonardo, before returning to Vesalius. The practice of artists studying corpses, in order to better understand the structure of the body was well established by the time Leonardo began his apprenticeship under Andrea del Verrocchio (c. 1435 – 1488), in fact Verrocchio insisted on his apprentices making detailed studies of the human body with its muscles, sinews etc. Leonardo simply took these studies further that his artist colleagues. He carried out his dissections, without any subterfuge, together with the physician and professor of anatomy Marcantonio della Torre (1481–1511).


Leonard anatomical study of the arm (c. 1510) Source: Wikimedia Commons

Vesalius is, as already stated, often credited with being the first to practice human dissection since antiquity but as you can see Torre, who died three years before Vesalius was born, was practicing dissection with Leonardo, so Vesalius definitely not the first. In fact, Vesalius was a high point, but by no means the end point in a development that had been going on for at least one and a half centuries. The earliest recorded dissection took place in Padua in 1341 but the Anatomia of Mondino de’ Liuzzi (c. 1270–1326) dates from 1316, indicating an earlier well-established practice. In the late fifteenth century universities began to erect temporary dissection theatres in winter for the anatomy professors to carry out public dissections for their students. These would later be replaced with permanent anatomical theatres, with the first being built in Padua in 1595.


The Padua anatomy theatre designed by Hieronymous Fabricius , 1595. In Giacomo Filippo Tomasini, Gymnasum Patavinum (udine: Nicolaus Schirattus, 1654) Houghton Library via Wikimedia Commons

Vesalius worked in such structures well before he published his De fabrica. With his book Vesalius did set new standards, but these were rapidly developed further by his contemporaries and successors. The standard popular story surrounding Vesalius is, in the sense of my title, very much a simplified falsification.

My third example is one on the most well-known figures in the popular history of science, Francis Bacon (1561–1626). Bacon is credited, with his Of Proficience and Advancement of Learning Divine and Human published in 1605 and his New Atlantis published posthumously in 1626, “with presenting a universal reform of knowledge into scientific methodology and the improvement of mankind’s state using the scientific method”, to quote Wikipedia.


Title page of New Atlantis in the second edition of Francis Bacon’s Sylva sylvarvm: or A naturall historie. In ten centvries. London. Printed by J.H. for William Lee at the Turkes Head in Fleet-street, next to the Miter, 1628 Source: Wikimedia Commons

The only problem with this presentation of Bacon, as the creator of a vision for the future of science is that all the ideas and concepts that he presents had been developed and practiced by natural philosophers over the previous two centuries. Bacon was not presenting a vision for the future but rather a codification and idealisation of what had been evolving in science in the past. Bacon was a recorder of other peoples’ advances and developments and not the visionary prophet, as which he is presented.


In the three examples that I have sketched it should be clear that what popularisers attempt to do with their simplifications and falsifications is to create hero stories, myths, rather than confront the complex, tangled up mess that is the real history of science. Or as Will Thomas, Renaissance Mathematicus friend put it in a recent tweet , “Totally different from standing before the vast, unknowable chaos of the historical record.”






Filed under History of science, Myths of Science

The man who printed the world of plants

Abraham Ortelius (1527–1598) is justifiably famous for having produced the world’s first modern atlas, that is a bound, printed, uniform collection of maps, his Theatrum Orbis Terrarum. Ortelius was a wealthy businessman and paid for the publication of his Theatrum out of his own pocket, but he was not a printer and had to employ others to print it for him.


Abraham Ortelius by Peter Paul Rubens , Museum Plantin-Moretus via Wikimedia Commons

A man who printed, not the first 1570 editions, but the important expanded 1579 Latin edition, with its bibliography (Catalogus Auctorum), index (Index Tabularum), the maps with text on the back, followed by a register of place names in ancient times (Nomenclator), and who also played a major role in marketing the book, was Ortelius’ friend and colleague the Antwerp publisher, printer and bookseller Christophe Plantin (c. 1520–1589).


Plantin also published Ortelius’ Synonymia geographica (1578), his critical treatment of ancient geography, later republished in expanded form as Thesaurus geographicus (1587) and expanded once again in 1596, in which Ortelius first present his theory of continental drift.


Plantin’s was the leading publishing house in Europe in the second half of the sixteenth century, which over a period of 34 years issued 2,450 titles. Although much of Plantin’s work was of religious nature, as indeed most European publishers of the period, he also published many important academic works.

Before we look in more detail at Plantin’s life and work, we need to look at an aspect of his relationship with Ortelius, something which played an important role in both his private and business life. Both Christophe Plantin and Abraham Ortelius were members of a relatively small religious cult or sect the Famillia Caritatis (English: Family of Love), Dutch Huis der Leifde (English: House of Love), whose members were also known as Familists.

This secret sect was similar in many aspects to the Anabaptists and was founded and led by the prosperous merchant from Münster, Hendrik Niclaes (c. 1501–c. 1580). Niclaes was charged with heresy and imprisoned at the age of twenty-seven. About 1530 he moved to Amsterdam where his was once again imprisoned, this time on a charge of complicity in the Münster Rebellion of 1534–35. Around 1539 he felt himself called to found his Famillia Caritatis and in 1540 he moved to Emden, where he lived for the next twenty years and prospered as a businessman. He travelled much throughout the Netherlands, England and other countries combining his commercial and missionary activities. He is thought to have died around 1580 in Cologne where he was living at the time.


Niclaes wrote vast numbers of pamphlets and books outlining his religious views and I will only give a very brief outline of the main points here. Familists were basically quietists like the Quakers, who reject force and the carrying of weapons. Their ideal was a quite life of study, spiritualist piety, contemplation, withdrawn from the turmoil of the world around them. The sect was apocalyptic and believed in a rapidly approaching end of the world. Hendrik Niclaes saw his mission in instructing mankind in the principal dogma of love and charity. He believed he had been sent by God and signed all his published writings H. N. a Hillige Nature (Holy Creature). The apocalyptic element of their belief meant that adherents could live the life of honest, law abiding citizens even as members of religious communities because all religions and authorities would be irrelevant come the end of times. Niclaes managed to convert a surprisingly large group of successful and wealthy merchants and seems to have appealed to an intellectual cliental as well. Apart from Ortelius and Plantin, the great Dutch philologist, humanist and philosopher Justus Lipsius (1574–1606) was a member, as was Charles de l’Escluse (1526–1609), better known as Carolus Clusius, physician and the leading botanist in Europe in the second half of the sixteenth century. The humanist Andreas Masius (1514–1573) an early syriacist (one who studies Syriac, an Aramaic language) was a member, as was Benito Arias Monato (1527–1598) a Spanish orientalist. Emanuel van Meteren (1535–1612) a Flemish historian and nephew of Ortelius was probably also Familist. The noted Flemish miniature painter and illustrator, Joris Hoefnagel (1542–1601), was a member as was his father a successful diamond dealer. Last but by no means least Pieter Bruegel the Elder (c. 1525– 1569) was also a Familist. As we shall see the Family of Love and its members played a significant role in Plantin’s life and work.


Christophe Plantin by Peter Paul Rubens Museum Platin-Moretus  via Wikimedia Commons Antwerp in the time of Plantin was a major centre for artists and engravers and Peter Paul Rubins was the Plantin house portrait painter.

Christophe Plantin was born in Saint-Avertin near Tours in France around 1520. He was apprenticed to Robert II Macé in Caen, Normandy from whom he learnt bookbinding and printing. In Caen he met and married Jeanne Rivière (c. 1521–1596) in around 1545.


Jeanne Rivière School of Rubens Museum Plantin-Moretus via Wikimedia Commons

They had five daughters, who survived Plantin and a son who died in infancy. Initially, they set up business in Paris but shortly before 1550 they moved to the city of Antwerp in the Spanish Netherlands, then one of Europe’s most important commercial centres. Plantin became a burgher of the city and a member of the Guild of St Luke, the guild of painter, sculptors, engravers and printers. He initially set up as a bookbinder and leather worker but in 1555 he set up his printing office, which was most probably initially financed by the Family of Love. There is some disagreement amongst the historians of the Family as to how much of Niclaes output of illegal religious writings Plantin printed. But there is agreement that he probably printed Niclaes’ major work, De Spiegel der Gerechtigheid (Mirror of Justice, around 1556). If not the house printer for the Family of Love, Plantin was certainly one of their printers.

The earliest book known to have been printed by Plantin was La Institutione di una fanciulla nata nobilmente, by Giovanni Michele Bruto, with a French translation in 1555, By 1570 the publishing house had grown to become the largest in Europe, printing and publishing a wide range of books, noted for their quality and in particular the high quality of their engravings. Ironically, in 1562 his presses and goods were impounded because his workmen had printed a heretical, not Familist, pamphlet. At the time Plantin was away on a business trip in Paris and he remained there for eighteen months until his name was cleared. When he returned to Antwerp local rich, Calvinist merchants helped him to re-establish his printing office. In 1567, he moved his business into a house in Hoogstraat, which he named De Gulden Passer (The Golden Compasses). He adopted a printer’s mark, which appeared on the title page of all his future publications, a pair of compasses encircled by his moto, Labore et Constantia (By Labour and Constancy).


Christophe Plantin’s printers mark, Source: Wikimedia Commons


Engraving of Plantin with his printing mark after Goltzius Source: Wikimedia Commons

Encouraged by King Philip II of Spain, Plantin produced his most famous publication the Biblia Polyglotta (The Polyglot Bible), for which Benito Arias Monato (1527–1598) came to Antwerp from Spain, as one of the editors. With parallel texts in Latin, Greek, Syriac, Aramaic and Hebrew the production took four years (1568–1572). The French type designer Claude Garamond (c. 1510–1561) cut the punches for the different type faces required for each of the languages. The project was incredibly expensive and Plantin had to mortgage his business to cover the production costs. The Bible was not a financial success, but it brought it desired reward when Philip appointed Plantin Architypographus Regii, with the exclusive privilege to print all Roman Catholic liturgical books for Philip’s empire.



In 1576, the Spanish troops burned and plundered Antwerp and Plantin was forced to pay a large bribe to protect his business. In the same year he established a branch of his printing office in Paris, which was managed by his daughter Magdalena (1557–1599) and her husband Gilles Beys (1540–1595). In 1578, Plantin was appointed official printer to the States General of the Netherlands. 1583, Antwerp now in decline, Plantin went to Leiden to establish a new branch of his business, leaving the house of The Golden Compasses under the management of his son-in-law, Jan Moretus (1543–1610), who had married his daughter Martine (1550–16126). Plantin was house publisher to Justus Lipsius, the most important Dutch humanist after Erasmus nearly all of whose books he printed and published. Lipsius even had his own office in the printing works, where he could work and also correct the proofs of his books. In Leiden when the university was looking for a printer Lipsius recommended Plantin, who was duly appointed official university printer. In 1585, he returned to Antwerp, leaving his business in Leiden in the hands of another son-in-law, Franciscus Raphelengius (1539–1597), who had married Margaretha Plantin (1547–1594). Plantin continued to work in Antwerp until his death in 1589.


Source: Museum Plantin-Moretus

After this very long introduction to the life and work of Christophe Plantin, we want to take a look at his activities as a printer/publisher of science. As we saw in the introduction he was closely associated with Abraham Ortelius, in fact their relationship began before Ortelius wrote his Theatrum. One of Ortelius’ business activities was that he worked as a map colourer, printed maps were still coloured by hand, and Plantin was one of the printers that he worked for. In cartography Plantin also published Lodovico Guicciardini’s (1521–1589) Descrittione di Lodovico Guicciardini patritio fiorentino di tutti i Paesi Bassi altrimenti detti Germania inferiore (Description of the Low Countries) (1567),


Source: Wikimedia Commons

which included maps of the various Netherlands’ cities.


Engraved and colored map of the city of Antwerp Source: Wikimedia Commons

Plantin contributed, however, to the printing and publication of books in other branches of the sciences.

Plantin’s biggest contribution to the history of science was in botany.  A combination of the invention of printing with movable type, the development of both printing with woodcut and engraving, as well as the invention of linear perspective and the development of naturalism in art led to production spectacular plant books and herbals in the Early Modern Period. By the second half of the sixteenth century the Netherlands had become a major centre for such publications. The big three botanical authors in the Netherlands were Carolus Clusius (1526–1609), Rembert Dodoens (1517–1585) and Matthaeus Loblius (1538–1616), who were all at one time clients of Plantin.

Matthaeus Loblius was a physician and botanist, who worked extensively in both England and the Netherlands.

NPG D25673,Matthias de Lobel (Lobelius),by Francis Delaram

Matthias de Lobel (Lobelius),by Francis Delaramprint, 1615 Source: Wikimedia Commons

His Stirpium aduersaria noua… (A new notebook of plants) was originally published in London in 1571, but a much-extended edition, Plantarum seu stirpium historia…, with 1, 486 engravings in two volumes was printed and published by Plantin in 1576. In 1581 Plantin also published his Dutch herbal, Kruydtboek oft beschrÿuinghe van allerleye ghewassen….


Source: Wikimedia Commons

There is also an anonymous Stirpium seu Plantarum Icones (images of plants) published by Plantin in 1581, with a second edition in 1591, that has been attributed to Loblius but is now thought to have been together by Plantin himself from his extensive stock of plant engravings.

Carolus Clusius also a physician and botanist was the leading scientific horticulturist of the period, who stood in contact with other botanist literally all over the worlds, exchanging information, seeds, dried plants and even living ones.


Portrait of Carolus Clusius painted in 1585 Attributed to Jacob de Monte – Hoogleraren Universiteit Leiden via Wikimedia Commons

His first publication, not however by Plantin, was a translation into French of Dodoens’ herbal of which more in a minute. This was followed by a Latin translation from the Portuguese of Garcia de Orta’s Colóquios dos simples e Drogas da India, Aromatum et simplicium aliquot medicamentorum apud Indios nascentium historia (1567) and a Latin translation from Spanish of Nicolás Monardes’  Historia medicinal delas cosas que se traen de nuestras Indias Occidentales que sirven al uso de la medicina, , De simplicibus medicamentis ex occidentali India delatis quorum in medicina usus est (1574), with a second edition (1579), both published by Plantin.His own  Rariorum alioquot stirpium per Hispanias observatarum historia: libris duobus expressas (1576) and Rariorum aliquot stirpium, per Pannoniam, Austriam, & vicinas quasdam provincias observatarum historia, quatuor libris expressa … (1583) followed from Plantin’s presses. His Rariorum plantarum historia: quae accesserint, proxima pagina docebit (1601) was published by Plantin’s son-in-law Jan Moretus, who inherited the Antwerp printing house.


Our third physician-botanist, Rembert Dodoens, his first publication with Plantin was his Historia frumentorum, leguminum, palustrium et aquatilium herbarum acceorum, quae eo pertinent (1566) followed by the second Latin edition of his  Purgantium aliarumque eo facientium, tam et radicum, convolvulorum ac deletariarum herbarum historiae libri IIII…. Accessit appendix variarum et quidem rarissimarum nonnullarum stirpium, ac florum quorumdam peregrinorum elegantissimorumque icones omnino novas nec antea editas, singulorumque breves descriptiones continens… (1576) as well as other medical books.


Rembert Dodoens Theodor de Bry – University of Mannheim via Wikimedia Commons

His most well known and important work was his herbal originally published in Dutch, his Cruydeboeck, translated into French by Clusius as already stated above.


Title page of Cruydt-Boeck,1618 edition Source: Wikimedia Commons

Plantin published an extensively revised Latin edition Stirpium historiae pemptades sex sive libri XXXs in 1593.


This was largely plagiarised together with work from Loblius and Clusius by John Gerrard (c. 1545–1612)


John Gerard Source: Wikimedia Commons

in his English herbal, Great Herball Or Generall Historie of Plantes (1597), which despite being full of errors became a standard reference work in English.

The Herball, or, Generall historie of plantes / by John Gerarde

Platin also published a successful edition of Juan Valverde de Amusco’s Historia de la composicion del cuerpo humano (1568), which had been first published in Rome in 1556. This was to a large extent a plagiarism of Vesalius’ De humani corporis fabrica (1543).


Another area where Platin made a publishing impact was with the works of the highly influential Dutch engineer, mathematician and physicist Simon Stevin (1548-1620). The Plantin printing office published almost 90% of Stevin’s work, eleven books altogether, including his introduction into Europe of decimal fractions De Thiende (1585),


Source: Wikimedia Commons

his important physics book De Beghinselen der Weeghconst (The Principles of Statics, lit. The Principles of the Art of Weighing) (1586),


Source: Wikimedia Commons

his Beghinselen des Waterwichts (Principles of hydrodynamics) (1586) and his book on navigation De Havenvinding (1599).

Following his death, the families of his sons-in-law continued the work of his various printing offices, Christophe Beys (1575–1647), the son of Magdalena and Gilles, continued the Paris branch of the business until he lost his status as a sworn printer in 1601. The family of Franciscus Raphelengius continued printing in Leiden for another two generations, until 1619. When Lipsius retired from the University of Leiden in 1590, Joseph Justus Scaliger (1540-1609) was invited to follow him at the university. He initially declined the offer but, in the end, when offered a position without obligations he accepted and moved to Leiden in 1593. It appears that the quality of the publications of the Plantin publishing office in Leiden helped him to make his decision.  In 1685, a great-granddaughter of the last printer in the Raphelengius family married Jordaen Luchtmans (1652 –1708), who had founded the Brill publishing company in 1683.

The original publishing house in Antwerp survived the longest. Beginning with Jan it passed through the hands of twelve generations of the Moretus family down to Eduardus Josephus Hyacinthus Moretus (1804–1880), who printed the last book in 1866 before he sold the printing office to the City of Antwerp in 1876. Today the building with all of the companies records and equipment is the Museum Plantin-Moretus, the world’s most spectacular museum of printing.


2-021 Museum Plantin Moretus

There is one last fascinating fact thrown up by this monument to printing history. Lodewijk Elzevir (c. 1540–1617), who founded the House of Elzevir in Leiden in 1583, which published both Galileo’s Discorsi e dimostrazioni matematiche intorno a due nuove scienze in 1638 and Descartes’ Discours de la Méthode Pour bien conduire sa raison, et chercher la vérité dans les sciences in 1637, worked for Plantin as a bookbinder in the 1560s.


Nikolaes Heinsius the Elder, Poemata (Elzevier 1653), Druckermarke Source: Wikimedia Commons

The House of Elzevir ceased publishing in 1712 and is not connected to Elsevier the modern publishing company, which was founded in 1880 and merely borrowed the name of their famous predecessor.

The Platntin-Moretus publishing house played a significant role in the intellectual history of Europe over many decades.




Filed under Book History, History of Mathematics, History of medicine, History of Physics, History of science, Renaissance Science

Renaissance Science – I

To paraphrase what is possibly the most infamous opening sentence in a history of science book[1], there was no such thing as Renaissance science, and this is the is the start of a blog post series about it. Put another way there are all sorts of problems with the term or concept Renaissance Science, several of which should entail abandoning the use of the term and in a later post I will attempt to sketch the problems that exist with the term Renaissance itself and whether there is such a thing as Renaissance science? Nevertheless, I intend to write a blog post series about Renaissance science starting today.

We could and should of course start with the question, which Renaissance? When they hear the term Renaissance, most non-historians tend to think of what is often referred to as the Humanist Renaissance, but historians now use the term for a whole series of period in European history or even for historical periods in other cultures outside of Europe.

Renaissance means rebirth and is generally used to refer to the rediscovery or re-emergence of the predominantly Greek, intellectual culture of antiquity following a period when it didn’t entirely disappear in Europe but was definitely on the backburner for several centuries following the decline and collapse of the Western Roman Empire. The first point to note is that this predominantly Greek, intellectual culture didn’t disappear in the Eastern Roman Empire centred round its capitol Constantinople. An empire that later became known as the Byzantine Empire. The standard myth is that the Humanist Renaissance began with the fall of Byzantium to the Muslims in 1453 but it is just that, a myth.


Raphael’s ‘School of Athens’ (1509–1511) symbolises the recovery of Greek knowledge in the Renaissance Source: Wikimedia Commons

As soon as one mentions the Muslims, one is confronted with a much earlier rebirth of predominantly Greek, intellectual culture, when the, then comparatively young, Islamic Empire began to revive and adopt it in the eight century CE through a massive translation movement of original Greek works covering almost every subject. Writing in Arabic, Arab, Persian, Jewish and other scholars, actively translated the complete spectrum of Greek science into Arabic, analysed it, commented on it, and expanded and developed it, over a period of at least eight centuries.  It is also important to note that the Islamic scholars also collected and translated works from China and India, passing much of the last on to Europe together with the Greek works later during the European renaissances.


The city of Baghdad 150–300 AH (767 and 912 CE) centre of the Islamic recovery and revival of Greek scientific culture Source: Wikimedia Commons

Note the plural at the end of the sentence. Many historians recognise three renaissances during the European Middle Ages. The first of these is the Carolingian Renaissance, which dates to the eighth and ninth century CE and the reigns of Karl der Große (742–814) (known as Charlemagne in English) and Louis the Pious (778–840).


Charlemagne (left) and Pepin the Hunchback (10th-century copy of 9th-century original) Source: Wikimedia Commons

This largely consisted of the setting up of an education system for the clergy throughout Europe and increasing the spread of Latin as the language of learning. Basically, not scientific it had, however, an element of the mathematical sciences, some mathematics, computus (calendrical calculations to determine the date of Easter), astrology and simple astronomy due to the presence of Alcuin of York (c. 735–804) as the leading scholar at Karl’s court in Aachen.


Rabanus Maurus Magnentius (left) another important teacher in the Carolignian Renaissance with Alcuin (middle) presenting his work to Otgar Archbishop of Mainz a supporter of Louis the Pious Source: Wikimedia Commons

Through Alcuin the mathematical work of the Venerable Bede (c. 673–735), (who wrote extensively on mathematical topics and who was also the teacher of Alcuin’s teacher, Ecgbert, Archbishop of York) flowed onto the European continent and became widely disseminated.


The Venerable Bede writing the Ecclesiastical History of the English People, from a codex at Engelberg Abbey in Switzerland. Source: Wikimedia Commons

Karl’s Court had trade and diplomatic relations with the Islamic Empire and there was almost certainly some mathematical influence there in the astrology and astronomy practiced in the Carolingian Empire. It should also be noted that Alcuin and associates didn’t start from scratch as some knowledge of the scholars from late antiquity, such as Boethius (477–524), Macrobius (fl. c. 400), Martianus Capella (fl. c. 410–420) and Isidore of Seville (c. 560–636) had survived. For example, Bede quotes from Isidore’s encyclopaedia the Etymologiae.

The second medieval renaissance was the Ottonian Renaissance in the eleventh century CE during the reigns of Otto I (912–973), Otto II (955–983), and Otto III (980–1002). The start of the Ottonian Renaissance is usually dated to Otto I’s second marriage to Adelheid of Burgundy (931–999), the widowed Queen of Italy in 951, uniting the thrones of Germany (East Francia) and Italy, which led to Otto being crowned Holy Roman Emperor by the Pope in 962.


Statues of Otto I, right, and Adelaide in Meissen Cathedral. Otto and Adelaide were married after his annexation of Italy. Source: Wikimedia Commons

This renaissance was largely confined to the Imperial court and monasteries and cathedral schools. The major influences came from closer contacts with Byzantium with an emphasis on art and architecture.

There was, however, a strong mathematical influence brought about through Otto’s patronage of Gerbert of Aurillac (c. 946–1003). A patronage that would eventually lead to Gerbert becoming Pope Sylvester II.


Sylvester, in blue, as depicted in the Evangelistary of Otto III Source: Wikimedia Commons

A monk in the Monastery of St. Gerald of Aurillac, Gerbert was taken by Count Borrell II of Barcelona to Spain, where he came into direct contact with Islamic culture and studied and learnt some astronomy and mathematics from the available Arabic sources. In 969, Borrell II took Gerbert with him to Rome, where he met both Otto I and Pope John XIII, the latter persuaded Otto to employ Gerbert as tutor for his son the future Otto II. Later Gerbert would exercise the same function for Otto II’s son the future Otto III. The close connection with the Imperial family promoted Gerbert’s ecclesiastical career and led to him eventually being appointed pope but more importantly in our context it promoted his career as an educator.

Gerbert taught the whole of the seven liberal arts, as handed down by Boethius but placed special emphasis on teaching the quadrivium–arithmetic, geometry, music and astronomy–bringing in the knowledge that he had acquired from Arabic sources during his years in Spain. He was responsible for reintroducing the armillary sphere and the abacus into Europe and was one of the first to use Hindu-Arabic numerals, although his usage of them had little effect. He is also reported to have used sighting tubes to aid naked-eye astronomical observations.

Gerbert was not a practicing scientist but rather a teacher who wrote a series of textbook on the then mathematical sciences: Libellus de numerorum divisione, De geometria, Regula de abaco computi, Liber abaci, and Libellus de rationali et ratione uti.


12th century copy of De geometria Source: Wikimedia Commons

His own influence through his manuscripts and his letters was fairly substantial and this was extended by various of his colleagues and students. Abbo of Fleury (c. 945–1004), a colleague, wrote extensively on computus and astronomy, Fulbert of Chartres (c. 960–1028), a direct student, also introduced the use of the Hindu-Arabic numerals. Hermann of Reichenau (1013–1054 continued the tradition writing on the astrolabe, mathematics and astronomy.

Gerbert and his low level, partial reintroduction into Europe of the mathematical science from out of the Islamic cultural sphere can be viewed as a precursor to the third medieval renaissance the so-called Scientific Renaissance with began a century later at the beginning of the twelfth century. This was the mass translation of scientific works, across a wide spectrum, from Arabic into Latin by European scholars, who had become aware of their own relative ignorance compared to their Islamic neighbours and travelled to the border areas between Europe and the Islamic cultural sphere of influence in Southern Italy and Spain. Some of them even travelling in Islamic lands. This Scientific Renaissance took place over a couple of centuries and was concurrent with the founding of the European universities and played a major role in the later Humanist Renaissance to which it was viewed by the humanists as a counterpart. We shall look at it in some detail in the next post.

[1] For any readers, who might not already know, the original quote is, “There was no such thing as the Scientific Revolution, and this is a book about it”, which is the opening sentence of Stevin Shapin’s The Scientific Revolution, The University of Chicago Press, Chicago and London, 1996


Filed under History of science, Mediaeval Science, Renaissance Science, Uncategorized

The emergence of modern astronomy – a complex mosaic: Part LII

This is a concluding summary to my The emergence of modern astronomy – a complex mosaic blog post series. It is an attempt to produce an outline sketch of the path that we have followed over the last two years. There are, at the appropriate points, links to the original posts for those, who wish to examine a given point in more detail. I thank all the readers, who have made the journey with me and in particular all those who have posted helpful comments and corrections. Constructive comments and especially corrections are always very welcome. For those who have developed a taste for a continuous history of science narrative served up in easily digestible slices at regular intervals, a new series will start today in two weeks if all goes according to plan!

There is a sort of standard popular description of the so-called astronomical revolution that took place in the Early Modern period that goes something liker this. The Ptolemaic geocentric model of the cosmos ruled unchallenged for 1400 years until Nicolas Copernicus published his trailblazing De revolutionibus in 1453, introducing the concept of the heliocentric cosmos. Following some initial resistance, Kepler with his three laws of planetary motion and Galileo with his revelatory telescopic discoveries proved the existence of heliocentricity. Isaac Newton with his law of gravity in his Principia in 1687 provided the physical mechanism for a heliocentric cosmos and astronomy became modern. What I have tried to do in this series is to show that this version of the story is almost totally mythical and that in fact the transition from a geocentric to a heliocentric model of the cosmos was a long drawn out, complex process that took many stages and involved many people and their ideas, some right, some only half right and some even totally false, but all of which contributed in some way to that transition.

The whole process started at least one hundred and fifty years before Copernicus published his magnum opus, when at the beginning of the fifteenth century it was generally acknowledged that astronomy needed to be improved, renewed and reformed. Copernicus’ heliocentric hypothesis was just one contribution, albeit a highly significant one, to that reform process. This reform process was largely triggered by the reintroduction of mathematical cartography into Europe with the translation into Latin of Ptolemaeus’ Geōgraphikḕ Hyphḗgēsis by Jacopo d’Angelo (c. 1360 – 1411) in 1406. A reliable and accurate astronomy was needed to determine longitude and latitude. Other driving forces behind the need for renewal and reform were astrology, principally in the form of astro-medicine, a widened interest in surveying driven by changes in land ownership and navigation as the Europeans began to widen and expand their trading routes and to explore the world outside of Europe.


The Ptolemaic Cosmos: Andreas Cellarius, Harmonia Macrocosmica 1660 Source: Wikimedia Commons

At the beginning of the fifteenth century the predominant system was an uneasy marriage of Aristotelian cosmology and Ptolemaic astronomy, uneasy because they contradicted each other to a large extent. Given the need for renewal and reform there were lively debates about almost all aspects of the cosmology and astronomy throughout the fifteenth and sixteenth centuries, many aspects of the discussions had their roots deep in the European and Islamic Middle Ages, which shows that the 1400 years of unchallenged Ptolemaic geocentricity is a myth, although an underlying general acceptance of geocentricity was the norm.

A major influence on this programme of renewal was the invention of moving type book printing in the middle of the fifteenth century, which made important texts in accurate editions more readily available to interested scholars. The programme for renewal also drove a change in the teaching of mathematics and astronomy on the fifteenth century European universities. 

One debate that was new was on the nature and status of comets, a debate that starts with Toscanelli in the early fifteenth century, was taken up by Peuerbach and Regiomontanus in the middle of the century, was revived in the early sixteenth century in a Europe wide debate between Apian, Schöner, Fine, Cardano, Fracastoro and Copernicus, leading to the decisive claims in the 1570s by Tycho Brahe, Michael Mästlin, and Thaddaeus Hagecius ab Hayek that comets were celestial object above the Moon’s orbit and thus Aristotle’s claim that they were a sub-lunar meteorological phenomenon was false. Supralunar comets also demolished the Aristotelian celestial, crystalline spheres. These claims were acknowledged and accepted by the leading European Ptolemaic astronomer, Christoph Clavius, as were the claims that the 1572 nova was supralunar. Both occurrences shredded the Aristotelian cosmological concept that the heaven were immutable and unchanging.

The comet debate continued with significant impact in 1618, the 1660s, the 1680s and especially in the combined efforts of Isaac Newton and Edmund Halley, reaching a culmination in the latter’s correct prediction that the comet of 1682 would return in 1758. A major confirmation of the law of gravity.

During those early debates it was not just single objects, such as comets, that were discussed but whole astronomical systems were touted as alternatives to the Ptolemaic model. There was an active revival of the Eudoxian-Aristotelian homocentric astronomy, already proposed in the Middle Ages, because the Ptolemaic system, of deferents, epicycles and equant points, was seen to violate the so-called Platonic axioms of circular orbits and uniform circular motion. Another much discussed proposal was the possibility of diurnal rotation, a discussion that had its roots in antiquity. Also, on the table as a possibility was the Capellan system with Mercury and Venus orbiting the Sun in a geocentric system rather than the Earth.


The Copernican Cosmos: Andreas Cellarius, Harmonia Macrocosmica 1660 Source: Wikimedia Commons

Early in the sixteenth century, Copernicus entered these debates, as one who questioned the Ptolemaic system because of its breaches of the Platonic axioms, in particular the equant point, which he wished to ban. Quite how he arrived at his radical solution, replace geocentricity with heliocentricity we don’t know but it certainly stirred up those debates, without actually dominating them. The reception of Copernicus’ heliocentric hypothesis was complex. Some simply rejected it, as he offered no real proof for it. A small number had embraced and accepted it by the turn of the century. A larger number treated it as an instrumentalist theory and hoped that his models would deliver more accurate planetary tables and ephemerides, which they duly created. Their hopes were dashed, as the Copernican tables, based on the same ancient and corrupt data, proved just as inaccurate as the already existing Ptolemaic ones. Of interests is the fact that it generated a serious competitor, as various astronomers produced geo-heliocentric systems, extensions of the Capellan model, in which the planets orbit the Sun, which together with the Moon orbits the Earth. Such so-called Tychonic or semi-Tychonic systems, named after their most well-known propagator, incorporated all the acknowledged advantages of the Copernican model, without the problem of a moving Earth, although some of the proposed models did have diurnal rotation.


The Tychonic Cosmos: Andreas Cellarius, Harmonia Macrocosmica 1660 Source: Wikimedia Commons

The problem of inaccurate planetary tables and ephemerides was already well known in the Middle Ages and regarded as a major problem. The production of such tables was seen as the primary function of astronomy since antiquity and they were essential to all the applied areas mentioned earlier that were the driving forces behind the need for renewal and reform. Already in the fifteenth century, Regiomontanus had set out an ambitious programme of astronomical observation to provide a new data base for such tables. Unfortunately, he died before he even really got started. In the second half of the sixteenth century both Wilhelm IV Landgrave of Hessen-Kassel and Tycho Brahe took up the challenge and set up ambitious observation programmes that would eventually deliver the desired new, more accurate astronomical data.

At the end of the first decade of the seventeenth century, Kepler’s Astronomia Nova, with his first two planetary laws (derived from Tycho’s new accurate data), and the invention of the telescope and Galileo’s Sidereus Nuncius with his telescopic discoveries are, in the standard mythology, presented as significant game changing events in favour of heliocentricity. They were indeed significant but did not have the impact on the system debate that is usually attributed them. Kepler’s initial publication fell largely on deaf ears and only later became relevant. On Galileo’s telescopic observations, firstly he was only one of a group of astronomers, who in the period 1610 to 1613 each independently made those discoveries, (Thomas Harriot and William Lower, Simon Marius, Johannes Fabricius, Odo van Maelcote and Giovanni Paolo Lembo, and Christoph Scheiner) but what did they show or prove? The lunar features were another nail in the coffin of the Aristotelian concept of celestial perfection, as were the sunspots. The moons of Jupiter disproved the homocentric hypothesis. Most significant discovery was the of the phases of Venus, which showed that a pure geocentric model was impossible, but they were conform with various geo-heliocentric models.

1613 did not show any clarity on the way to finding the true model of the cosmos but rather saw a plethora of models competing for attention. There were still convinced supporters of a Ptolemaic model, both with and without diurnal rotation, despite the phases of Venus. Various Tychonic and semi-Tychonic models, once again both with and without diurnal rotation. Copernicus’ heliocentric model with its Ptolemaic deferents and epicycles and lastly Kepler’s heliocentric system with its elliptical orbits, which was regarded as a competitor to Copernicus’ system. Over the next twenty years the fog cleared substantially and following Kepler’s publication of his third law, his Epitome Astronomiae Copernicanae, which despite its title is a textbook on his elliptical system and the Rudolphine Tables, again based on Tycho’s data, which delivered the much desired accurate tables for the astrologers, navigators, surveyors and cartographers, and also of Longomontanus’ Astronomia Danica (1622) with his own tables derived from Tycho’s data presenting an updated Tychonic system with diurnal rotation, there were only two systems left in contention.

Around 1630, we now have two major world systems but not the already refuted geocentric system of Ptolemaeus and the largely forgotten Copernican system as presented in Galileo’s Dialogo but Kepler’s elliptical heliocentricity and a Tychonic system, usually with diurnal rotation. It is interesting that diurnal rotation became accepted well before full heliocentricity, although there was no actually empirical evidence for it. In terms of acceptance the Tychonic system had its nose well ahead of Kepler because of the lack of any empirical evidence for movement of the Earth.

Although there was still not a general acceptance of the heliocentric hypothesis during the seventeenth century the widespread discussion of it in continued in the published astronomical literature, which helped to spread knowledge of it and to some extent popularise it. This discussion also spread into and even dominated the newly emerging field of proto-sciencefiction.

Galileo’s Dialogo was hopelessly outdated and contributed little to nothing to the real debate on the astronomical system. However, his Discorsi made a very significant and important contribution to a closely related topic that of the evolution of modern physics. The mainstream medieval Aristotelian-Ptolemaic cosmological- astronomical model came as a complete package together with Aristotle’s theories of celestial and terrestrial motion. His cosmological model also contained a sort of friction drive rotating the spheres from the outer celestial sphere, driven by the unmoved mover (for Christians their God), down to the lunar sphere. With the gradual demolition of Aristotelian cosmology, a new physics must be developed to replace the Aristotelian theories.

Once again challenges to the Aristotelian physics had already begun in the Middle Ages, in the sixth century CE with the work of John Philoponus and the impetus theory, was extended by Islamic astronomers and then European ones in the High Middle Ages. In the fourteenth century the so-called Oxford Calculatores derived the mean speed theorem, the core of the laws of fall and this work was developed and disseminated by the so-called Paris Physicists. In the sixteenth century various mathematicians, most notably Tartaglia and Benedetti developed the theories of motion and fall further. As did in the early seventeenth century the work of Simon Stevin and Isaac Beeckman. These developments reached a temporary high point in Galileo’s Discorsi. Not only was a new terrestrial physics necessary but also importantly for astronomy a new celestial physics had to be developed. The first person to attempt this was Kepler, who replaced the early concept of animation for the planets with the concept of a force, hypothesising some sort of magnetic force emanating from the Sun driving the planets around their orbits. Giovanni Alfonso Borelli also proposed a system of forces as the source of planetary motion.

Throughout the seventeenth century various natural philosophers worked on and made contributions to defining and clarifying the basic terms that make up the science of dynamics: force, speed, velocity, acceleration, etc. as well as developing other areas of physics, Amongst them were Simon Stevin, Isaac Beeckman, Borelli, Descartes, Pascal, Riccioli and Christiaan Huygens. Their efforts were brought together and synthesised by Isaac Newton in his Principia with its three laws of motion, the law of gravity and Kepler’s three laws of planetary motion, which laid the foundations of modern physics.

In astronomy telescopic observations continued to add new details to the knowledge of the solar system. It was discovered that the planets have diurnal rotation, and the periods of their diurnal rotations were determined. This was a strong indication the Earth would also have diurnal rotation. Huygens figured out the rings of Saturn and discovered Titan its largest moon. Cassini discovered four further moons of Saturn. It was already known that the four moons of Jupiter obeyed Kepler’s third law and it would later be determined that the then known five moons of Saturn also did so. Strong confirming evidence for a Keplerian model.

Cassini showed by use of a heliometer that either the orbit of the Sun around the Earth or the Earth around the Sun was definitively an ellipse but could not determine which orbited which. There was still no real empirical evidence to distinguish between Kepler’s elliptical heliocentric model and a Tychonic geo-heliocentric one, but a new proof of Kepler’s disputed second law and an Occam’s razor argument led to the general acceptance of the Keplerian model around 1660-1670, although there was still no empirical evidence for either the Earth’s orbit around the Sun or for diurnal rotation. Newton’s Principia, with its inverse square law of gravity provided the physical mechanism for what should now best be called the Keplerian-Newtonian heliocentric cosmos.

Even at this juncture with a very widespread general acceptance of this Keplerian-Newtonian heliocentric cosmos there were still a number of open questions that needed to be answered. There were challenges to Newton’s work, which, for example, couldn’t at that point fully explain the erratic orbit of the Moon around the Earth. This problem had been solved by the middle of the eighteenth century. The mechanical philosophers on the European continent were anything but happy with Newton’s gravity, an attractive force that operates at a distance. What exactly is it and how does it function? Questions that even Newton couldn’t really answer. Leibniz also questioned Newton’s insistence that time and space were absolute, that there exists a nil point in the system from which all measurement of these parameters are taken. Leibniz preferred a relative model.

There was of course also the very major problem of the lack of any form of empirical evidence for the Earth’s movement. Going back to Copernicus nobody had in the intervening one hundred and fifty years succeeded in detecting a stellar parallax that would confirm that the Earth does indeed orbit the Sun. This proof was finally delivered in 1725 by Samuel Molyneux and James Bradley, who first observed, not stellar parallax but stellar aberration. An indirect proof of diurnal rotation was provided in the middle of the eighteenth century, when the natural philosophers of the French Scientific Academy correctly determined the shape of the Earth, as an oblate spheroid, flattened at the pols and with an equatorial bulge, confirming the hypothetical model proposed by Newton and Huygens based on the assumption of a rotating Earth.

Another outstanding problem that had existed since antiquity was determining the dimensions of the known cosmos. The first obvious method to fulfil this task was the use of parallax, but whilst it was already possible in antiquity to determine the distance of the Moon reasonably accurately using parallax, down to the eighteenth century it proved totally impossible to detect the parallax of any other celestial body and thus its distance from the Earth. Ptolemaeus’ geocentric model had dimensions cobbled together from its data on the crystalline spheres. One of the advantages of the heliocentric model is that it gives automatically relative distances for the planets from the sun and each other. This means that one only needs to determine a single actually distance correctly and all the others are automatically given. Efforts concentrated on determining the distance between the Earth and the Sun, the astronomical unit, without any real success; most efforts producing figures that were much too small.

Developing a suggestion of James Gregory, Edmond Halley explained how a transit of Venus could be used to determine solar parallax and thus the true size of the astronomical unit. In the 1760s two transits of Venus gave the world the opportunity to put Halley’s theory into practice and whilst various problems reduced the accuracy of the measurements, a reasonable approximation for the Sun’s distance from the Earth was obtained for the very first time and with it the actually dimensions of the planetary part of the then known solar system. What still remained completely in the dark was the distance of the stars from the Earth. In the 1830s, three astronomers–Thomas Henderson, Friedrich Wilhelm Bessel and Friedrich Georg Wilhelm von Struve–all independently succeeded in detecting and measuring a stellar parallax thus completing the search for the dimensions of the known cosmos and supplying a second confirmation, after stellar aberration, for the Earth’s orbiting the Sun.

In 1851, Léon Foucault, exploiting the Coriolis effect first hypothesised by Riccioli in the seventeenth century, finally gave a direct empirical demonstration of diurnal rotation using a simple pendulum, three centuries after Copernicus published his heliocentric hypothesis. Ironically this demonstration was within the grasp of Galileo, who experiment with pendulums and who so desperately wanted to be the man who proved the reality of the heliocentric model, but he never realised the possibility. His last student, Vincenzo Viviani, actually recorded the Coriolis effect on a pendulum but didn’t realise what it was and dismissed it as an experimental error.

From the middle of the eighteenth century, at the latest, the Keplerian-Newtonian heliocentric model had become accepted as the real description of the known cosmos. Newton was thought not just to have produced a real description of the cosmos but the have uncovered the final scientific truth. This was confirmed on several occasions. Firstly, Herschel’s freshly discovered new planet Uranus in 1781 fitted Newton’s theories without problem, as did the series of asteroids discovered in the early nineteenth century. Even more spectacular was the discovery of Neptune in 1846 based on observed perturbations from the path of Uranus calculated with Newton’s theory, a clear confirmation of the theory of gravity. Philosophers, such as Immanuel Kant, no longer questioned whether Newton had discovered the true picture of the cosmos but how it had been possible for him to do so.


However, appearances were deceptive, and cracks were perceptible in the Keplerian-Newtonian heliocentric model. Firstly, Leibniz’s criticism of Newton’s insistence on absolute time and space rather than a relative model would turn out to have been very perceptive. Secondly, Newton’s theory of gravity couldn’t account for the observed perihelion precession of the planet Mercury. Thirdly in the 1860s, based on the experimental work of Michael Faraday, James Maxwell produced a theory of electromagnetism, which was not compatible with Newtonian physics. Throughout the rest of the century various scientists including Hendrik Lorentz, Georg Fitzgerald, Oliver Heaviside, Henri Poincaré, Albert Michelson and Edward Morley tried to find a resolution to the disparities between the Newton’s and Maxwell’s theories. Their efforts finally lead to Albert Einstein’s Special Theory of Relativity and then on to his General theory of Relativity, which could explain the perihelion precession of the planet Mercury. The completion of the one model, the Keplerian-Newtonian heliocentric one marked the beginnings of the route to a new system that would come to replace it.


Filed under History of Astronomy, History of science, Newton, Renaissance Science

Illuminating medieval science


There is a widespread popular vision of the Middle ages, as some sort of black hole of filth, disease, ignorance, brutality, witchcraft and blind devotion to religion. This fairly-tale version of history is actively propagated by authors of popular medieval novels, the film industry and television, it sells well. Within this fantasy the term medieval science is simply an oxymoron, a contradiction in itself, how could there possible be science in a culture of illiterate, dung smeared peasants, fanatical prelates waiting for the apocalypse and haggard, devil worshipping crones muttering curses to their black cats?

Whilst the picture I have just drawn is a deliberate caricature this negative view of the Middle Ages and medieval science is unfortunately not confined to the entertainment industry. We have the following quote from Israeli historian Yuval Harari from his bestselling Sapiens: A Brief History of Humankind (2014), which I demolished in an earlier post.

In 1500, few cities had more than 100,000 inhabitants. Most buildings were constructed of mud, wood and straw; a three-story building was a skyscraper. The streets were rutted dirt tracks, dusty in summer and muddy in winter, plied by pedestrians, horses, goats, chickens and a few carts. The most common urban noises were human and animal voices, along with the occasional hammer and saw. At sunset, the cityscape went black, with only an occasional candle or torch flickering in the gloom.

On medieval science we have the even more ignorant point of view from American polymath and TV star Carl Sagan from his mega selling television series Cosmos, who to quote the Cambridge History of Medieval Science:

In his 1980 book by the same name, a timeline of astronomy from Greek antiquity to the present left between the fifth and the late fifteenth centuries a familiar thousand-year blank labelled as a “poignant lost opportunity for mankind.” 

Of course, the very existence of the Cambridge History of Medieval Science puts a lie to Sagan’s poignant lost opportunity, as do a whole library full of monographs and articles by such eminent historians of science as Edward Grant, John Murdoch, Michael Shank, David Lindberg, Alistair Crombie and many others.

However, these historians write mainly for academics and not for the general public, what is needed is books on medieval science written specifically for the educated layman; there are already a few such books on the market, and they have now been joined by Seb Falk’s truly excellent The Light Ages: The Surprising Story of Medieval Science.[1]  


How does one go about writing a semi-popular history of medieval science? Falk does so by telling the life story of John of Westwyk an obscure fourteenth century Benedictine monk from Hertfordshire, who was an astronomer and instrument maker. However, John of Westwyk really is obscure and we have very few details of his life, so how does Falk tell his life story. The clue, and this is Falk’s masterstroke, is context. We get an elaborate, detailed account of the context and circumstances of John’s life and thereby a very broad introduction to all aspects of fourteenth century European life and its science.

We follow John from the agricultural village of Westwyk to the Abbey of St Albans, where he spent the early part of his life as a monk. We accompany some of his fellow monks to study at the University of Oxford, whether John studied with them is not known.


Gloucester College was the Benedictine College at Oxford where the monks of St Albans studied

We trudge all the way up to Tynemouth on the wild North Sea coast of Northumbria, the site of daughter cell of the great St Alban’s Abbey, main seat of Benedictines in England. We follow John when he takes up the cross and goes on a crusade. Throughout all of his wanderings we meet up with the science of the period, John himself was an astronomer and instrument maker.

Falk is a great narrator and his descriptive passages, whilst historically accurate and correct,[2] read like a well written novel pulling the reader along through the world of the fourteenth century. However, Falk is also a teacher and when he introduces a new scientific instrument or set of astronomical tables, he doesn’t just simply describe them, he teachers the reader in detail how to construct, read, use them. His great skill is just at the point when you think your brain is going to bail out, through mathematical overload, he changes back to a wonderfully lyrical description of a landscape or a building. The balance between the two aspects of the book is as near perfect as possible. It entertains, informs and educates in equal measures on a very high level.

Along the way we learn about medieval astronomy, astrology, mathematics, medicine, cartography, time keeping, instrument making and more. The book is particularly rich on the time keeping and the instruments, as the Abbott of St Albans during John’s time was Richard of Wallingford one of England’s great medieval scientists, who was responsible for the design and construction of one of the greatest medieval church clocks and with his Albion (the all in one) one of the most sophisticated astronomical instruments of all time. Falk’ introduction to and description of both in first class.


The book is elegantly present with an attractive typeface and is well illustrated with grey in grey prints and a selection of colour ones. There are extensive, informative endnotes and a good index. If somebody reads this book as an introduction to medieval science there is a strong chance that their next question will be, what do I read next. Falk gives a detailed answer to this question. There is an extensive section at the end of the book entitled Further Reading, which gives a section by section detailed annotated reading list for each aspect of the book.

Seb Falk has written a brilliant introduction to the history of medieval science. This book is an instant classic and future generations of schoolkids, students and interested laypeople when talking about medieval science will simply refer to the Falk as a standard introduction to the topic. If you are interested in the history of medieval science or the history of science in general, acquire a copy of Seb Falk’s masterpiece, I guarantee you won’t regret it.

[1] American edition: Seb Falk, The Light Ages: The Surprising Story of Medieval Science, W. W. Norton & Co., New York % London, 2020

British Edition: Seb Falk, The Light Ages: A Medieval Journey of Discover, Allen Lane, London, 2020

[2] Disclosure: I had the pleasure and privilege of reading the whole first draft of the book in manuscript to check it for errors, that is historical errors not grammatical or orthographical ones, although I did point those out when I stumbled over them.


Filed under History of Astrology, History of Astronomy, History of Cartography, History of Mathematics, History of Navigation, History of science, Mediaeval Science, Myths of Science