ABSTRACT
This chapter unveils the non-empirical and deductive character of the actual approach and argumentation of the pre-eminent scientists. Theories evolved by pure deduction, recommended for purely logical reasons or on considerations simply of mathematical elegance and coherence, are non-empirical and must be recognized as purely formal, giving no information about the real world. The Copernican revolution is commonly regarded as the turning-point at which speculative theorizing gave way to observation and experiment as the source and support of scientific theory. The aberrant movements of the planets were explained by the Greeks as due to the revolution of transparent crystal spheres, into which the celestial region was divided, and which according to different theories were alleged to rotate in various ways. The Tychonic system attempts to combine Copernicus doctrine with Ptolemys in a new way, making the planets revolve around the sun, but the sun and the moon revolve around the earth as the fixed centre of the universe.
