The Medieval Synthesis

By the Middle Ages, the Ptolemaic picture took on a new power as the philosophy of Aristotle (newly rediscovered in Europe) was wedded to medieval theology in the great synthesis of Christianity and Reason undertaken by philsopher-theologians such as Thomas Aquinas. The Prime Mover of Aristotle's universe became the God of Christian theology, the outermost sphere of the Prime Mover became identified with the Christian Heaven, and the position of the Earth at the center of it all was understood in terms of the concern that the Christian God had for the affairs of mankind.

Thus, ideas largely originating with pagan Greek philosophers were baptized into the Catholic church and eventually assumed the power of religious dogma: to challenge this view of the Universe was not merely a scientific issue, but a theological one as well, and subjected dissenters to the considerable and not always benevolent power of the Church.