Astrology is fake and wrong, said Saint Augustine of Hippo 1,600 years ago.
Today, many people believe in astrology, although most practitioners don't take it extremely seriously. After the latest outburst about Ophiuchus, a supposedly new zodiac sign, this popular belief has temporarily come to the forefront of cyberspace.
However, back in Augustine's time, astrology -- loosely defined as attempts to predict personal future based on the position of celestial bodies -- was a more serious matter. Indeed, men considered to be sophisticated, learned, and scholarly claimed they could predict earthly affairs by studying the relative positions of heavenly bodies.
The study of heavenly bodies in itself, defined as astronomy, is a legitimate (and serious) scientific field methodically observed by many ancient civilizations before Augustine's time. From their observations, these civilizations derived remarkably accurate calendars and erected astronomically aligned structures.
Augustine doesn't discredit astronomy.
What's utterly fake, he said, is astrology, i.e. applying astronomy to predict personal fortunes.
Augustine quoted someone as saying astronomy is like a lottery in which the astrology expert predicts many things. Some of those things, of course, were bound to come true. Believers in astrology tend to remember the ones that did and forget the ones that did not.
He also told a highly interesting story.
One rich man took great pains to record the birth of his boy and the birth of his friend's slave's boy, which happened exactly at the same time, i.e. both children were delivered at the same instant, right down to the lesser divisions of the hour.
These two boys, then, were constrained to allow the same constellations, even to the minutest points. So if astrology were real, they'd have similar fates.
However, the rich boy grew up to be a man and ran his course through the gilded paths of life, was increased in riches, raised to honors while the slave's boy continued to serve his masters, without any relaxation of his yoke.
Moreover, by the same logic, twins should have identical fates. While many twins indeed have similar lives (but that's because of chance and the similar circumstances of their upbringing), those that have different fortunes all serve as examples to resolutely refute astrology.
Augustine said if an astrologer made a correct prediction, it was not out of skill but chance. If an astrologer made a wrong prediction, it was not out of ignorance in the art (misreading the stars) but chance also.