Can astrology be disproved? Literally thousands of volumes have been written on the subject over the ages, attacks and defenses, apologies and interpretations. Proponents have claimed astrology as a "science" and an "art," a true interpretation of the inner workings of the universe. Opponents have mostly attacked astrology on physical grounds, citing the old classical arguments: the question of twins, the time of birth versus time of conception, the immense distances to the planets and stars, and so on.
But very few writers have come to the nub of the matter: astrology is false because it is a system of magic, based on the magical "principle of correspondences." In fact, astrology--or at least its prehistoric predecessor--probably arose concurrently with the magical world view of early civilized man, astrology and magic adding to each other and being developed and used by the priests to lend "cohesiveness" to the evolving city-states. By the time cuneiform and hieroglyphic writing had been developed, astrology in some form or other was already a part of man's culture.
Thus, several thousand years have gone into the development of astrology, into its theory and practice. Astrology proper began in Babylonia as a system of omen-reading to foretell the fate of kings and realms. More or less simultaneously, the Egyptians developed their system of Places, based on "planetary aspects." Then the Greeks took over both the Babylonian and Egyptian systems, combining them into a complex mathematical cosmology. Under the Greeks, astrology became available to the common man; astrologers today use virtually the same system as the Greeks, or endless variations thereof.
As a result of astrology's long history, confused development, and obscured theoretical bases, it is common for writers and astrologers to state that the ancient "art" cannot be disproved, that modern man lacks the necessary "cosmic insights" to grasp its truths. Even the great humanist Petrarch attacked astrology only by making fun of astrologers, leaving the cosmological arguments relatively untouched. Very few writers indeed have associated astrology with its magical bases; a reasonable search reveals that only Isidore of Seville, in the seventh century, and Richard Cavendish, in The Black Arts ( 1967), have properly identified astrology as magic.
This confused state of affairs is precisely the astrologers' aim: as long as they can obscure the fact that astrology is nothing more nor less than magic and totally unrelated to physical science, they can continue to find customers willing to part with hard-earned funds. For, after all, astrology is a practical "art"; it has provided many an astrologer with a lifelong living.