Some time back the Aussie Anthropoid (aka OOwilkins the Bond Professor) posted a Mr Deity video the theme of which was all of the gifts that he was going to bestow on his chosen people. Lucy compares his list with everything that Zeus is giving the Greeks such as science, medicine and astronomy at which point Mr Deity interrupts to say how much he loves astronomy and to ask if she had seen Larry’s horoscope for that day… Lucy answers “that’s astrology not astronomy” “yer, what’s the difference” asks Mr D. “About 50 IQ points!” Lucy fires back. A truly great line and one that John chose as the subtitle of his post. However one commentator spoiled the joke by pointing out that the Greek’s also practiced astrology to which John gave a short but fairly accurate answer. Inspired by this exchange I have decided to do a series of posts on the intertwined history of the two disciplines of which this forms a sort of introduction.
Words and Concepts:
Today most people have a fairly clear view of the division between astrology and astronomy but from the time of the ancient Greeks up to the 18th century the lexicographical difference between the two concepts was anything but clear. In the first footnote to his brilliant book “ Mathematik und Astronomie an der Universität Ingolstadt im 15. und 16. Jahrhundert” * Christoph Schöner writes that in the Renaissance the words astrologus, astronomus and mathematicus are synonymous, a comment that could equally apply to the preceding two thousand years. In the literature from the Greeks up to the end of the 17th century you will find authors who use astrology for what we consider to be astronomy and astronomy for that which we call astrology. Other authors use astrology or astronomy for both disciplines. In a famous quote Augustinus warns Christians to beware of mathematicians thus demonstrating for some people his anti science attitude. His defenders correctly point out that although he uses the word mathematici he is actually referring to astrologers. This defence is in fact correct and it’s obvious from the rest of the quote that Augustinus is indeed warning his fellow Christians of the dangers of astrology and other forms of divination. However the defence looses some of its strength if one realises that in the time of Augustinus mathematicians and astrologers were one and the same.
For the purposes of these posts I shall be ahistorical and treat the concepts astrology and astronomy as if they had always had clear and separate definitions and in fact those assigned to them by Ptolemaeus in the definitive Greek work on astrology his Tetrabiblos. Here Ptolemaeus writes that the study of the heavens is divided into two disciplines, astronomy, which is the study of the movement of heavenly bodies and astrology, which is the study of their influence. These are the definitions for the two words that I will be using but I should point out that Ptolemaeus himself did not stick to this clear division and in fact mixed up the two terms in his writing like everybody else.
Astrology is more than horoscopes:
Today when people hear the word astrology they, like Mr Deity, think automatically of horoscopes but in fact horoscope astrology is only one aspect, and a comparatively late one at that, of the discipline, which covers a very wide range of celestial influences. In the course of these posts I shall touch upon the origins of horoscope astrology and also deal in some detail with a couple of other aspect of astrology that are not based on horoscopes.
Astrology doesn’t actually exist:
This subtitle is not a sceptical rejection of the claims of astrology but in fact a denial that the discipline astrology exists at all. Anyone who has read so far will probably at this moment think that I have gone insane. I write a post explaining that I shall be writing a series of posts on the history of astrology and now I am denying that it exists at all, how come. The point that I wish to make and it a very important one is that people talk about astrology as if it were a clearly defined single discipline but this is not the case. One thing that makes the study of the history of astrology extremely difficult is that there is not one coherent astrology but literally hundreds of conflicting and even contradictory astrologies. In fact there are almost as many different astrologies as there are authors on the subjects and a large part of the astrological literature consists of the authors explain why their system is the one true correct one and all the others are wrong. What is interesting is that in their disputes mediaeval and Renaissance astronomers will often call upon the same Greek authorities to justify contradictory positions. On the whole I shall again be ahistorical and write as if there were one unified discipline of astrology throughout its history.
Disclaimer: I am not an expert:
Regular readers of this blog will know that my main interest as a historian of science is the evolution of the mathematical sciences between about 1400 and 1750 (I will explain those dates one day). Now nearly all of the practicing mathematicians in this period, at least up to about 1650, were not just astrologers but the wish to reform astrology and set it up on a firm empirical footing was one of the main driving forces of their work so if you really want to understand them as a historian you have to engage with astrology and its history, which over the years I have done. Now if somebody had said to me thirty years ago that I would spend substantial amounts of my time reading astrology books or books about astrology I would have recommended them a good psychiatrist, however that is exactly what I have done in the last years and although I now have a reasonable working knowledge of some aspects of the history of astrology and its practitioners, particularly in the Renaissance I am anything but an expert on the subject. The history of astrology is an incredible complex, multi-dimensional and twisted subject and I’m very glad that people, who are much better historians than I, have devoted their time and considerable talent to it thus enabling me to distil their collective wisdom from their books and papers. What will follow in the later posts in this series are some thoughts and conclusions that have crystallised out of my readings on the subject and are by no means authoritative but I hope will be at least somewhat informative and possibly stimulate the reader into rethinking their own view of the role of astrology in the history of western thought and in particular science.
* If you read German this book, Schreiner’s doctoral thesis, contains in the first 150 pages the best account of the teaching of mathematics in the European mediaeval universities that has ever been written (it’s one of my bibles!).