Parmenides argued that inquiry must distinguish the way of truth from unreliable mortal opinion, pressing later thinkers to explain being, thought, and change.
Intellectual setting
His poem framed a goddess's revelation as an argument about the conditions for thought and speech, becoming a decisive provocation for pluralists and atomists.
Key ideas
What is
The truth section argues that what is cannot arise, perish, or be divided as ordinary appearances suggest.
Mortal opinion
A second part presents a cosmology whose precise relation to the truth argument remains a major interpretive problem.
Legacy
Parmenides set the terms for later debates about whether reason can overturn the testimony of sense experience.