In AD312 the Emnperor Constantine became a convert to Christianity and instigated a campaign against pagan practices. In AD358 astrologers were among those threatened with death. Over the following centuries the most antagonistic of Christian theologians were however somewhat confused by the apparent scientific basis of astrology, and what seemed a very obvious relationship between medicine and astrology which it would be foolish, they thought, to deny. Their attempts to assert that some areas of the sbject were theologically dangerous while others were permissable resulted in great confusion. The major example of a precarious balance between the two attitudes to astrology was seen in the wrok of the Grerek philosopher Plotinus, who asserted that men and women must be in control of their own destiny, while aspects of their life - including their physical health - were evidently influenced by the planets. There was also the difficulty, for those Christians who abhorred astrology, that God had apparently chosen to signify the birth of his Son by astrological means; the easy way out was to have it both ways, as did Tertullian, who accepted the Star of Bethlehem while asserting that the twelve planets had now been replaced by the twelve Apostles. Others, Origen among them, teetered uneasily on the edge of accepting 'the stars' as having been placed in the sky by God as symbols, while failing to reconcile this with the suspicion that astrology was deeply anti-Christian. St Augustine was a fierce critic of astrology as a thing of the Devil, though many of his arguments were based on a fallacious understanding of the history of the subject. Later, medieval Christians found it easier to reconcile their faith with their view of astrology as a useful tool which God had given them; many of the Popes were sympathetic, accepting the dedication of books on astrology, sometimes empoloying their own astrologers, and in a few cases being themselves competent astrologers. It was even permissable to speculate about the horocope of Christ Himself, and from the 13th century onwards the development of natural science seemed to support the view that it was impossible to deny the effects that the planets had on the life of mankind - that, as Robert Grossetest, the Bishop of Lincoln, put it, 'nature below effects nothing unless celestial power moves it and directs it.'
It seemed possible at one time that astrology would becme totally acceptable, taught in every European university as a matter of copurse. The waves of approval and disapproval that affected the Christian view of the subject rose and fell over the centuries, however - at one extreme astrologers were persecuted and condemned (though there was no such pogrom against them as against alleged witches; and none was burned by the Inquisition), yet at the other extreme members of the clergy were openly practising astrology, in some cases positively from the altars of their churches. The opendulum swung decidedly against astrology after the Reformation, and Pope Sixtus V issued a papal bull in 1586 which had the result that Italian universities ceased to teach it. Elsewhere the Pope's condemnation had a more limited effect, which esulted in Pope Urban VIII subsequently condemning as heretichs everyone who approved of the subject (presumably including his papal forebears). Astrology however refused to die, and during the Renaissance there was renewed intellectial discussion of the subject. At a political and social level it was in the ascendant, and the voice of the Church as much diminished. With the coming of the Age of Enblightenment, churchmen - however suspicious they were of science - welcomed increasing criticism of astrology as a pseudo-science, and from then until the present day a steady but generally ineffectual antipathy has been maintained. The Catholic Church as might be expected has continued to condemn the study of the subject, and has been joined in general by other Churches, the fiercest condemnation coming from right-wing evangelists. Sunce it is probably the case that only diminishing number of modern astrologers assert that the prediction of events is possible, there seems no more reason why modern Christian should condemn astrology than that they should condemned psychiatry or weather-forecasting, but traddition dies hard.