Hippias of Elis was an itinerant Greek philosopher who contributed significantly to mathematics by discovering the quadratrix, a special curve he may have used to trisect an angle (see quadratrix of Hippias). Hippias is one of the first mathematicians about whom a good deal is known. He came from a state in the northwest corner of Peloponnesia that was the home of the Olympic games. According to Plato, Hippias boasted, during one of his visits to the Olympics, that everything he wore – his clothing, sandals, ring, and oil flask – he'd made himself. Later, in Athens, Hippias became one of the first to teach for money, a practice forbidden by the Pythagoreans and scorned upon by Plato. He and other paid teachers became known as "sophists," which was a derogatory term at the time but has since come to mean "wise man."