In Nicolaus Copernicus' time, no new phenomena to justify the idea of the Earth's motion, were discovered. However, not only was the heliocentric theory unable to explain heavenly motions any better than the geocentric one, but moving the Earth meant also, philosophically, moving man away from his traditional and privileged position at the centre of the World. Besides, the Earth's motion entails the rejection of established Aristotelian physics. Why then did Copernicus propose the heliocentric theory, and why did some of his contemporaries follow his hypothesis? Substantially, because the new architecture of the Cosmos offered a much more rational Universe, without the incongruity of the Ptolemaic system.
Copernicus believed in the existence of crystalline spheres, the heritage of the Greek and Islamic tradition, and also the most part of the technical solutions he adopted to explain the motion of the planets, are of Islamic origin. Therefore, many historians of science consider Copernicus to be the last ancient astronomer, rather than the first of the modern ones. More simply, Copernicus used the technical and conceptual apparatus of his time, and we must regard him as the author of new theories, which started the astronomical revolution.