Parmenides
... Parmenides philosophy is based on the idea that “the entire universe consists of one thing, which never changes, has no parts, and can never be destroyed.” This is what Parmenides refers to as the One. Parmenides theory contradicts that of Heraclitus, his predecessor, which dictates that all things change. Parmenides conceives “the perception of movement and change as an illusion and everything that is, has always been and will ever be, since it can always be thought and spoken of. ... Parmenides challenges that the non-existent can not be thought of, thus not allowing for the implications that something is not. According to Parmenides the One is immovable and indivisible: finite and spherical.