This is a tongue-in-cheek history and assessment of astrology by a data scientist, tracing its entwinement with astronomy and asking more interesting questions than a straight, rah-rah-go-science history would. The book moves forward through time, but maybe its most helpful to start at the surprising end: astrology only took a turn toward woo woo spiritualism and personality assessment via Theosophy and Carl Jung in the early 1900s. Before that date it took itself more seriously, was much more complex, and offered itself as of practical use: predicting not just life courses of emperors but also the prices of commodities. It also was regarded doubtfully even by practitioners.

A reason astrology hung on for so long had to do with the late development of statistical thinking. No one knew how to run a chi test or a regression; if they had it could have been thrown in the waste bin much earlier. The author playfully goes through the exercise, crunching the numbers on the star signs of Supreme Court Justices, eg. But he seems not much interested in the results, perhaps anticipating we wouldn't be either. Maybe that was an editorial choice because the slap-down empirical mood doesn't jibe with the generous spirit of the historical portions. Or else, maybe the choice to not press the statistical results was in recognition of the how arbitrarily the signs and coordinates and calendars that determine that "data" were drawn and redrawn over the centuries.

He suggests that although astrology was always bunk the reasons its critics gave for rejecting it were often weak. He endorses Carl Sagan's point that some theories later validated (eg, continental drift) were initially rejected because no conceivable mechanism could support them (tectonic plates were discovered only later), so we shouldn't have rejected astrology merely because we didn't know of a mechanism by which it could have worked. There's something to that, but I wish he had gone further into the "demarcation problem" and in philosophy of science, and how it has treated the paradigm pseudoscience that is astrology. He does cite Feyerabend's "The Strange Case of Astrology," but doesn't explain its content, which is an interesting takedown of both astrology and most of its critics.

Astrology is one of those subjects like psychic research: to the embarrassment of many it historically engaged some great thinkers. That makes it an interesting subject to trace through time, shining unusual sidelights on otherwise familiar developments and personalities in science. This book has a lot of value as a unusual history of thought and explanation of some related science, but it isn't--and, for reasons it hints at, couldn't be--the data scientific treatment it advertises itself as. ( )