Early fifth century BCE

Parmenides — Does speaking of change require speaking of what is not?

When we speak of coming-to-be and passing-away, are we really thinking what is not?

Evidence-backed account

Parmenides' poem divides routes of inquiry and presses radical constraints on what can be thought and spoken of as being.

Open evidence

This is an evidence-linked editorial paraphrase, not a direct quotation.

Parmenides
Stanford Encyclopedia of Philosophy
Locator: §2 Overview of Parmenides’ Poem; §3.2 The Way of Conviction
Open source

The slogan that he simply declares all change illusory is contested; contemporary scholarship offers competing monist and modal interpretations.

Open evidence

This is an evidence-linked editorial paraphrase, not a direct quotation.

Parmenides
Stanford Encyclopedia of Philosophy
Locator: §3 Some Main Types of Interpretation; §3.8 What Is and Cannot Not Be
Open source