Darin Hayton has a short post discussing a review of John Hessler’s A Renaissance Globemaker’s Toolbox, a new book about the cartographical endeavours of the Renaissance mathematicus Johannes Schöner. As well as being the addressee of Rheticus’ Naratio Prima, the first published account of Copernican heliocentricity, Schöner played a very central roll in the history of globe making as well as the evolution of cartography in the sixteenth century and it is with this aspect of his life that the new book is concerned. Schöner put together a private bound volume of cartographical material that he used for his own work. This volume contained, amongst other things, the only known copy of the first map to name the newly discovered western continent America, Martin Waldseemüller’s 1507 map of the world, that was purchased by the Library of Congress for ten million dollars in 2003. In his latest book Hassel analyses all the cartographical material contained in Schöner’s “toolbox” to develop a picture of how he worked. I might write more about this book when I’ve read it, I ordered it today, but here I’m concerned with one troubling paragraph of the review to which Darin has already drawn attention in his post. The reviewer, John Wilford, wrote at the end of his piece the following:
Nothing in the book points up more clearly Schöner’s pivotal place in a world in transition from the medieval to the modern than his residual interest in astrology and his awakening curiosity when he apparently heard reports of a new theory being formulated by a Polish Catholic cleric. A brilliant young student of Schöner’s, Georg Joachim Rheticus, went to see Copernicus in 1539 and learned more about the Earth orbiting the Sun. Rheticus then composed a short treatise, written in the form of a letter to his teacher, “most illustrious and learned” Johannes Schöner.
In his post Darin comments on this paragraph thus:
Schöner’s interest in that “new theory being formulated by a Polish Catholic cleric” probably owed more to his interest in astrology and making astrological prognostications than the modernity we see in Copernicus’s theory. Along with his prognostications and calendars, Schöner also wrote books on astrology before and after Copernicus’s De revolutionibus was published, notably his Opusculum Astrologicum in 1539 and De iudiciis nativitatum Libri Tres in 1545. Schöner might also have been the author of a horoscope cast for Copernicus. Judging from the table of contents, Hessler spends some time assessing Schöner’s astrology. Schöner’s interest in astrology shouldn’t diminish our interest in him, but it should, perhaps, prompt us to wonder about the labels “modern” and “medieval” and the work they do for us…
Darin criticism is right on the button and in what follows I would like to expand upon it somewhat and expose what I see as a common misconception concerning the history of astrology.
Darin is perfectly correct when he surmises that any interest that Schöner had in the work of Copernicus was almost certainly motivated by his very active interest in astrology and it should be noted that Schöner’s “brilliant young student”, Georg Joachim Rheticus, who famously undertook the arduous journey to Frauenburg to visit Copernicus did so after spending several months in Nürnberg studying astrology under Schöner. The central section of Rheticus’ Naratio Prima consists of an excurse on what he sees as a confirmation of an astrological cyclical theory of history, popular at the time amongst Renaissance scholars, delivered by Copernicus’ theory of the precession of the equinoxes. However I see a major problem in Wilford’s labelling of Schöner’s astrology as medieval.
Schöner’s astrology is Renaissance astrology and it is for various reasons a very different beast to medieval astrology. His astrological practice cannot and should not be seen, as Wilford wishes us to do so, as a residual left over from earlier times but as the, for the sixteenth century, central and actual activity of the working Renaissance mathematicus; Schöner’s astrology was modern.
European horoscope astrology, there are other sorts that I won’t discuss here, began life in Greece sometime in the fifth and fourth centuries BCE, combing elements of earlier Egyptian and Babylonian systems of prognostication. Its fortunes waxed and waned over the following centuries and reached a zenith in the work of Ptolemaeus in the second century CE. From here like all the other sciences of antiquity, and its adherents certainly regarded it as a science, it went into decline, almost disappearing completely in the Early Middle Ages. Although it should be pointed out that those works of astronomy from antiquity that remained known in this period such as Martianus Capella’s De nuptiis Philologiae et Mercurii and Microbius’ Commentarii in Somnium Scipionis are strongly astrological.
With the first major revival of learning at the beginning of the High Middle Ages, twelfth and thirteenth centuries, and the rise of the European universities astrology enjoyed a rather dubious reputation. It stood in conflict with the dominating Catholic theology. Horoscope astrology with its seemingly deterministic prognostications appeared to contradict the central Church tenet, the belief in free will.
With the advent of Humanist Renaissance in the fifteenth century astrology enjoyed a major revival centred around astro-medicine, or as it was also known iatro-mathematics, a discipline that like astrology had its roots in fourth century BCE Greece. This form of medicine believed that the causes and cures of diseases were controlled by celestial influences and that a medicus must study the horoscopes of both the patient and the disease to determine the correct course of treatment. Chairs of astrology were established at the Northern Italian humanist universities and also in Cracow in Poland, later in other parts of Europe. By the end of the century astrology was the central discipline studied and practiced by the Renaissance mathematicus. This revival in the fortunes of astrology was also made possible because the new astrologers interpreted horoscopes as being indicative and no longer deterministic. That is a horoscope indicated a possible course for the future but one that could be altered by the subject of the horoscope if he took the right actions. Actions defined by the astrologer, of course, for a further fee.
In the sixteenth century at the start of the Reformation Philipp Melanchthon, who was responsible for the curricular of the Lutheran Protestant schools and university, established chairs for mathematics in all of the Protestant educational establishments to further the study of astrology of which he was a passionate adherent. Johannes Schöner professor for mathematics at the Egidian Oberschule in Nürnberg was one of the first of those appointees. Favoured for his already excellent reputation as an astrologer. Far from being a medieval residue Renaissance astrology, as practiced by Schöner, was a cutting edge academic discipline and for its time the epitome of modern.
Astrology was also not in the process of dying off following Schöner’s own demise in 1547 it continued to be a central field of study for the cartographers and astronomers who created the modern disciplines over the next hundred years. Both Gemma Frisius and Gerard Mercator, who are regarded as two of the principle founders of modern cartography and who were both highly influenced by Schöner’s work, were highly respected practicing astrologers. Rheticus the midwife of Copernican heliocentricity who became a medicus practicing astro-medicine in Cracow in the later part of his life gained a European wide reputation for his astrological prognostica. Michael Maestlin, Kepler’s teacher, and Tycho Brahe, his most significant employer, who each made important contribution to the evolution of the new astronomy were both practicing astrologers who regarded astrology as central to their astronomical research. Kepler himself, probably the most important of the modern astronomers, was also a passionate believer in celestial influence even if he rejected the traditional horoscope astrology and wished to replace it with one of his own devising. Finally even Galileo Galilei, supposedly the first really modern “scientist” taught astrology to the medicine student at the University of Padua a discipline that he himself obviously believed in as evidenced by the horoscopes that he drew up for his own family. This list of sixteenth and early seventeenth century astrologers is of course not exhaustive but merely an indication of just how deep the study and practice of astrology was embedded in the work of a Renaissance mathematicus.
Astrology first went into decline and lost its social and academic status in the second half of the seventeenth century with the general decline of the scholastic Aristotelian philosophy and with it the Renaissance belief in the micro-cosmos/ macro-cosmos philosophy, the fundamental justification for celestial influence and astrology.
Returning to the starting point of this post I hope I have made clear with my brief exposition of the history of European horoscope astrology that Schöner’s “residual interest in astrology” in no way indicates his “pivotal place in a world in transition from the medieval to the modern” as there was nothing medieval about his astrological activities for they were in themselves a sign of modernity in the sixteenth century.