Tag: Ptolemy

Astrology and Relationships

Over the last few days the Smithsonian Magazine has been drawing attention to their recent blog post about astrology and relationships (see this search): “Good News: Astrology Doesn’t Impact the Success of Your Marriage.” Unfortunately, the post missed an opportunity to ask interesting questions about why the study attacked astrology and why it represented as it did, and about why astrology remains such a mesmerizing target for scientists and science cheerleaders.

The Smithsonian Magazine’s tweets about astrology and relationships.
The Smithsonian Magazine’s tweets about astrology and relationships.

The post summarizes a study from 2007, which found little correlation between sun signs and choice of spouse, and an earlier study, which concluded that further research was needed to “to find out whether astrology columns really are just a bit of harmless fun or whether people’s behaviour is influenced without them realizing it.” Beyond link bait, it is unclear what the Smithsonian post was intended to accomplish. It invokes that old chestnut that reduces astrology to sun signs. As the comments indicate, it does not engender debate or discussion but rather encourages people to retrench into tired old positions. On the one had, the post reassures opponents of astrology of their righteous opposition and confirms for them that astrology lacks evidentiary support. On the other hand, the post goads proponents of astrology to point out the fallacious arguments that undergird the attacks.

A more interesting starting point would have been to ask: Why did the author of the study reduce astrology to sun signs? Further, why did he assume sun signs compel people to marry certain people?[1] That assumption contradicts the traditional aphorism: “The stars incline they do not compel.” Consequently, astrologers since Ptolemy have explained how astrology cannot be a precise, predictive science, certainly not when it comes to predicting human behavior. Who, then, believes that sun signs, one small facet of a much larger astrological edifice, can compel people into action? What does framing an attack on astrology in this way accomplish? Why, given the long history of attacks on astrology, did the author of the study think his criticism would be successful?[2]

Like all attacks on astrology, this one has a long history, complicated by the many different ways astrologers have claimed the stars and planets influence marriage. Ptolemy devoted a chapter to marriage in his Tetrabiblos. There he offered all sorts of guidelines for characterizing a marriage, such as:

Marriages for the most part are lasting when in both the genitures the luminaries happen to be in harmonious aspect, that is, in trine or in sextile with one another…

Or in other places he indicates what sorts of spouses people tend to marry:

If Saturn is similarly in aspect with the sun, they [women] marry sedate, useful, industrious husbands; if Jupiter is in aspect, dignified and magnanimous; Mars, men of action, lack in affection, and unruly; Venus, neat and handsome…

In Ptolemy’t discussion, astrological configurations portended certain circumstances but did not necessitate them. The configurations Ptolemy highlighted were much more complex than merely sun signs and often included detailed analyses of both the husband’s and the wife’s genitures as well as a comparison of the two.

Subsequent astrologers refined, modified, and extended Ptolemy’s doctrine. Nearly every early modern book on astrology includes rules for how to interpret celestial influences on marriages.[3] These guidelines range from a generic comment about seventh house being the house signifying marriage to John Middleton’s detailed discussion of whether or not a person will get married, when, how often, whether it will be a harmonious marriage, etc. As the various interpretations proliferated, so too did the attacks. Critics as different as the religious reformer Jean Calvin and the philosopher Pierre Gassendi wrote a scathing critiques of judicial astrology in which they rejected the astrologer’s ability to predict anything specific about a marriage, including whether a person would be happy in a marriage. The clergyman John Edwards, pointed out that whether or not astrology can make general predictions, astrology cannot predict particular aspects of a person’s life. He singles out marriage as one such aspect.

More than four centuries ago both opponents and proponents of astrology had already agreed that astrology could not make precise predictions about marriages. Why, then, bother trying to demonstrate that there is no correlation between sun signs and choice of a spouse? Whose interests are served by spending the time and effort on such a study? Who is the author of the study and the author of the post trying to convince? Why does astrology continue to serve as the paradigmatic pseudo-science? And what do attacks on astrology reveal about the social nature of scientific knowledge?


  1. The post gestures at the difference between astrology and horoscopes but does not explore that difference in any interesting way. The second study cited, concludes more ambiguously than the post suggests.  ↩

  2. These questions should not be understood as a defense of astrology. Rather, they merely raise questions about the unexamined assumptions and conventions that  ↩

  3. Modern texts on astrology might also include discussions about marriage. I don’t know anything about modern astrology textbooks, so I can’t say.  ↩

Haverford’s New Rare Book

The title page of Haverford’s new rare book: Ptolemy’s Centiloquium (1519)

As early as Monday Haverford’s Special Collection will have a new book: Claudius Ptolemy, Centum Ptolemaei sententiae ad Syrum fratrem à Pontano è graeco in latinum tralatae, atque expositae. Eiusdem Pontani libri XIIII (Aldine, 1519). For a number of reasons I am excited about this book. Perhaps obviously, my own research interests make this an important book—Ptolemy’s Centiloquium was one of the most widely used texts for teaching and practicing astrology in the early sixteenth century. More broadly this book indicates Haverford’s and the library’s commitment to Special Collections and acquiring new material to facilitate and extend faculty research. In our modern, iPad-Kindle-Nook, deliver-to-desktop, on-line centric world, we can easily loose sight of the wide range of materials that enable scholars to do their research. For me and scholars like me our research would be impossible without collections of books. In this way, to quote a colleague, the library is like the “laboratory for the humanities” and this book is an instrument in our research.