Aristotle’s philosophy of mathematics implies a kind of naïve realism that mathematical objects are nothing but properties of sensible objects. A problem of such mathematical naïve realism is that, unlike objects of other sciences, mathematical objects are not perfectly instantiated by sensible particulars; properties of sensible objects do not satisfy the definition of mathematical objects. Despite this problem, Aristotle could maintain his mathematical naïve realism due to Eudoxus’ astronomical achievement. Eudoxus reconstructed the original motions of stars by accounting for the irregularities and imperfection in terms of interplay between the rotations of four distinct spheres, and showed that stars’ circular spherical motions met criteria of geometrical absoluteness. Eudoxus’ new theory of astronomy, however, still does not justify Aristotelian mathematical naïve realism; for the motions of heavenly bodies do not instantiate every geometrical figure.