As the historian of mathematics Jean Dhombres so aptly puts it: "At the root of the Platonic philosophical outlook lies the distinction between the world of sensory objects, which are imperfect and, above all, changeable, and the world of their eternal models—the perfect and immutable Ideas."
Euclid's Elements are the crowning achievement of the Platonic view of mathematics.

Statue of Euclid at the Oxford University Museum of Natural History.