Before the scientific revolution

From the classical period through the scientific revolution, astrological training played a critical role in advancing astronomical, mathematical, medical and psychological knowledge. Astrological influences included the observation and long-term tracking of celestial objects. It was astrologers who provided the first systematic documentation of the movements of the Sun, the Moon, the planets, and the stars. The differentiation between astronomy and astrology varied from place to place; they were indistinguishable in ancient Babylonia and for most of the Middle Ages, but separated to a greater degree in ancient Greece (see astrology and astronomy). Astrology was not always uncritically accepted before the modern era; it was often challenged by Hellenistic skeptics, church authorities, and medieval thinkers.

The pattern of astronomical knowledge gained from astrological endeavours has been historically repeated across numerous cultures, from ancient India through the classical Maya civilization to medieval Europe. Given this historical contribution, astrology has been called a protoscience along with pseudosciences such as alchemy (see "Western astrology and alchemy" below).

Many prominent scientists, such as Nicholas Copernicus, Galileo Galilei, Tycho Brahe, Johannes Kepler, Carl Jung and others, practiced or significantly contributed to astrology.