 Aristotle takes a number of the Presocratics to endorse dialetheism, and with apparent justification. For example, in Fragment 49a, Heraclitus says: “We step and do not step into the same rivers; we are and we are not” (Robinson, 1987, p. 35). Protagorean relativism may be expressed by the view that man is the measure of all things; but according to Aristotle, since “Many men hold beliefs in which they conflict with one another”, it follows that “the same thing must be and not be” (1009a10–12). The Presocratic views triggered Aristotle’s attack in Metaphysics, Book \(\Gamma\). Chapter 4 of this Book contains Aristotle’s defence of the LNC. As we said above, historically Aristotle was almost completely successful: the LNC has been orthodoxy in Western Philosophy ever since.