One criterion is that of Protagoras, who holds that what appears to a person is true for that person, another is that of the Cyrenaics, who believe that there is no criterion whatsoever except the inmost feelings, another is that of Epicurus, who places the whole criterion in the senses and in the primary notions of things and in pleasure. On the other hand, Plato believed that the whole criterion of truth and truth itself lies merely in reasoning and in the mind, detached from belief and from the senses.

Aside from the philosophers that were set forth by us, in this gymnastic contest the stadium will also contain, stripped of all truth, those from the opposite side who took up arms against all the dogmatic philosophers put together (I mean the school of Pyrrho), and who declared that nothing amongst men is apprehensible, and also the school of Aristippus who maintain that only the pathē are apprehensible, and again the schools of Metrodorus and Protagoras, who hold that we must trust only the sensations of the body.