In his poem, Parmenides of Elea is taught by a goddess the way of truth: what is, is; what is not, cannot be thought. Being is therefore ungenerated, imperishable, whole and unmoving; the world of change belongs to the way of opinion. He has been compared with Advaita Vedānta.
Being (Parmenides)
Parmenides’ teaching that what is, is one, unchanging and indivisible, and that change and plurality are illusion.