The knowledge of the ancients had to be enormous. How close to many discoveries were the ancients, we see on the basis of the knowledge of Cicero, which refers in this case to Aristotle. Cicero and theory of relativity:
Aristotle is also to be commended for his view that the motion of all living bodies is due to one of three causes, nature, force, or will; now the sun and moon and all the stars are in motion.
Cicero and the force of gravity:
Bodies moved by nature travel either downwards owing to their weight or upwards owing to their lightness; but neither (he argued) is the case with the heavenly bodies, because their motion is revolution in a circle.
