The Marginalization of Astrology

March 19-20, 2015, Utrecht, Netherlands

The Descartes Centre for history of science of the University of Utrecht, in collaboration with the department of philosophy of Radboud University Nijmegen, will host an international conference on the marginalization of astrology in the early modern period.

Astrology has been a well-established and respected part of scholarship for centuries, practiced in many cultural and geographical settings. However, in the modern world, astrology, though still very much present, has lost its scientific status and has been relegated to the fringes of serious learning. In the history of scientific thought, this must be regarded as a momentous shift. The definite step in the “marginalization” of astrology appears to have been taken in the seventeenth century and should therefore be regarded as an important element (rather than a consequence) of the so-called Scientific Revolution.

The reasons for this development are far from clear. Actually, even the development itself (when, where and by whom did astrology become disavowed) has so far been only scantly documented. The conference therefore aims to shed light on this intriguing question by bringing together specialists from various fields.

The subject will be examined from multiple angles:

History of astrology. Although the conference is about people NOT practicing astrology rather than about astrologers, the history of astrology proper remains central. At the very least, an attempt should be made to compare differences in astrological practice (and their marginalization) between various local, cultural and religious contexts. Other relevant questions concern criticisms and apologies of astrology and attempts at astrological reform.

History of science. The idea that astrology was discredited directly because of new scientific discoveries is no longer regarded as credible; on the other hand, it does not appear plausible that there was no connection at all. The dismissal of astrology implied a transformation of the work and the identity of astronomers. In natural philosophy, it implied a rejection of the idea of celestial influence, which had become an integral part of scholastic philosophy.

History of medicine. Medicine was a major application of astrology. Medieval physicians would routinely cast horoscopes for diagnostic and other purposes. The question is when and how this changed. Obviously, both the supply and the demand sides have to be taken into account.

Court culture. Important on the side of demand were princely and noble courts. In the sixteenth century, princes would regularly employ court mathematicians/astronomers, whose task was to cast horoscopes. In the seventeenth century, on the other hand, Louis XIV spent a fortune on the Paris Observatory, yet casting horoscopes was not among the tasks of this institution. Again, the reasons behind this change are not clear.

Print culture. Almanacs, ephemerides, and prognostics, in conjunction with information on their makers, editions, and distribution, should enable us to get at least some idea of the popularity, or lack of popularity, of astrological ideas and practices. This is a field wherein some work has already been done.

History of religion. The era of the Reformation and Counter Reformation saw important developments in the field of theology, Church discipline and organization, which may have affected the status of astrology. One should also look to what one might call religious anthropology: shifting attitudes toward the supernatural and a changing definition of “superstition,” more or less identifiable with Weber’s “disenchantment of the world.” It is not clear to what extent astrology (as a learned practice) was placed in the same category as other superstitions, but the question should be asked.

Finally, the question to what extent this development remained limited to Western Europe, and whether similar things happened elsewhere (and when), should not be forgotten, even if an answer eludes us at this stage.

For more information on this conference:

Rienk Vermij, history of science, University of Oklahoma (

Hiro Hirai, department of philosophy, Radboud University Nijmegen (

Posted: July 18, 2014