  A fundamental tenet of Eleatic theory is that what-is-not cannot be (Parmenides DK 28 B2). Parmenides, using this claim (see DK 28 B8.15–16), argued that coming-to-be and passing-away are therefore ruled out, because genuine coming-to-be is change from what-is-not to what-is, while destruction is change from what-is to what-is-not. Thus, says Parmenides, what-is “is without start or stop, since coming to be and passing away have wandered very far away, and true trust drove them out”  (DK 28 B8.27–28).[1]   Anaxagoras accepts this principle, explaining apparent generation and destruction by replacing them with mixture and separation (or dissociation) of ingredients: