A form of divination based on the theory that the planets and stars influence human affairs.Until Copernicus (1473-1543), much of the lore of astrology was partial basis for astronomy. Since Copernicus, astrology and astronomy separated. In astrology a horoscope is a map of the heavens at the time of birth, using the chart of the zodiac. The "house," or sign in the ascendancy at the time of one's birth, is said to determine one's temperament, tendencies to disease, and liability to certain fortunes or calamities.
It is normally wrong to believe in astrology or to direct one's life and conduct according to its supposed predictions. The reasons are that astrology involves contradictions, since it claims uniform influence on persons born on the same day and in the same place, and who later on prove to be unmistakable different; it claims to predict accurately the free future, i.e., happenings that depend on the exercise of man's free will, whereas such knowledge is unknown to anyone except God; it is against the doctrine of free will, for it leads to fatalistic views of man's destiny; and it is against belief in divine providence, which includes the influence of divine grace and the value of intercessory prayer.
Astrology has been more than once formally condemned by the Church, as at the Council of Trent, which expressly forbade the faithful to read books on astrology dealing with "future contingent achievements, with fortuitous events and such actions as depend on human freedom, but daring to claim certitude about their occurrence" (Regulae Tridentinae, 9). Those who believe in astrology expose themselves to a weakening of their Christian faith. (Etym. Greek astron, star + logia, science, knowledge.)