A pupil of Nessus, or, as some accounts prefer, of Democritus himself, he was a complete sceptic. He accepted the Democritean theory of atoms and void and the plurality of worlds, but held a theory of his own that the stars are formed from day to day by the moisture in the air under the heat of the sun.
On the way he slays the centaur Nessus, who persuades Deianeira that his blood is a love-charm.
Thereupon Deianeira, prompted by love and jealousy, sends him a tunic dipped in the blood of Nessus, and the unsuspecting hero puts it on just before sacrificing at the headland of Cenaeum in Euboea.
A mythology reminiscent of Italy is the "Hercules and the Stymphalian Birds" in the Germanic Museum at Nuremberg, founded directly upon the "Hercules and Centaur Nessus" of Pollaiuolo, now at New Haven, Connecticut, U.S.A. Of portraits, besides that of his father already mentioned as done in 1497, there is his own of 1498 at Madrid.