(Circa 490– 420 BC) A pre-Socratic Greek philosopher who, according to Aristotle (in Rhetoric iii. v.), was the first thinker to notice and consider the concept of linguistic gender, i.e. the system for allocating parts of speech to masculine, feminine, and neuter categories.
1. He is also the philosopher who claimed the "man is the measure of all things," which makes him the primordial Humanist.