The discussion about the contribution of Plato to natural sciences in general and astronomy in particular have been lively and passionate in the last centuries. In the platonic work, besides the platonic exhortation to “ignore the visible heavens”, metaphysical beliefs and political considerations are strongly intermingled with scientific reflections, physics and mathematics of his time; nevertheless, the platonic ideas have marked our civilization. It is worth studying and analyzing these doctrines in order to better understand not only the evolution of scientific thinking over the centuries, but the character, features and essence of natural sciences, and in particular astronomy, as well.