Parmenides believed that he had found the most reliable way of theorizing about ultimate reality. While natural philosophers conceptualized phenomenal differences to explain cosmic change, Parmenides used the least meaningful but most versatile verb in Ancient Greek to engage in a purely intellectual exploration of reality – one that transcended synchronous and asynchronous differences. In this article I explain how the verb εἰμί was useful to Parmenides in his attempt to overcome natural philosophy. First, I argue that the Eleatic philosopher (...) regarded νοεῖν and εἶναι as equivalent because εἰμί-clauses enabled him to express arguably any conceivable content without providing significant additional meaning. I then show that Parmenides’ concept of being implies the present tense and the imperfective aspect but is grounded in the lexical content of the verb εἰμί, which entails no inherent temporal limits. This explains why ἔστι, ἐόν, and εἶναι could be used to indicate unbounded actuality, regardless of whether these forms represented lexical predicates or auxiliaries for predication. Finally, I maintain that the suitability of εἰμί for talking about all kinds of things without introducing temporal limits allowed Parmenides to avoid what he saw as two mistakes made by natural philosophers: identifying ultimate reality with something that cannot cover the full extent of thought and confusing actuality with present occurrence. (shrink)