After a long period of discredit and neglect, astrology is beginning to force itself once more on the attention of the learned world. In the course of the last few years scholars have devoted to it profound researches and elaborate publications. Greek manuscripts, which had remained a sealed book at a time when the quest for unpublished documents is all the rage, have now been laboriously examined, and the wealth of this literature has exceeded all expectation. On the other hand, the deciphering of the cuneiform tablets has given access to the wellsprings of a learned superstition, which up to modern times has exercised over Asia and Europe a wider dominion than any religion has ever achieved. I trust, therefore, that I am not guilty of undue presumption in venturing to claim your interest for this erroneous belief, so long universally accepted, which exercised an endless influence on the creeds and the ideas of the most diverse peoples, and which for that very reason necessarily demands the attention of historians.