- Lived:
- c. 515–450 BCE · Elea, a Greek city on the coast of southern Italy
- Tradition:
- Pre-Socratic Greek; founder of the Eleatic school — and of metaphysics itself
- The Big Idea:
- If you follow pure logic wherever it leads, reality must be one single, unchanging, eternal thing — and all change, motion, and variety must be an illusion.
- In their words:
- "It is, and it cannot not be."
- If you remember one thing:
- Parmenides was the first philosopher to argue — to build a chain of reasoning from premises to conclusion — and his argument proved something obviously insane that nobody could actually refute.