A celebrated Greek sophist, born at Syracuse, in Sicily; settled in Athens, a swashbuckler of a man, who attached himself to the Eleatics, and especially Zeno, in order that by their dialectic "he might demonstrate that nothing exists, or if something exists, that it cannot be known, or if it can be known, that it cannot be communicated"; his work bore characteristically enough the title "Of the Non-Existent, or of Nature"!