Parmenides of Elea (c. 520 – 450 BCE) was a priest of Apollo and founder of the Eleatic school of ancient Greek philosophy. Elea was a Greek city on the southern coast of Italy.

The only known surviving work by Parmenides is a 150-line poem fragment (supposedly from a 3,000-line original) known as “On Nature” that describes two views of reality: “The Way of Truth” and “The Way of Opinion.”

The work seems to describe the duality between appearance and reality, though it also seems to argue that movement and change are simply appearances of a static and eternal reality.

Parmenides’ ideas influenced Plato, and thereby much of western philosophy. The dualism at the heart of his writing relates closely to the narrator's concepts of "heaviness" versus "lightness," and the story will refer to Parmenides at several critical moments later on.