Apollonius then asked him [Iarchas] whether they knew themselves also, thinking that he, like the Greeks, would regard self-knowledge as a difficult matter. But the other, contrary to Apollonius' expectations, corrected him and said: "We know everything, just because we begin by knowing ourselves; for no one of us would be admitted to this philosophy unless he first knew himself." And Apollonius remembered what he had heard Phraotes say, and how he who would become a philosopher must examine himself before he undertakes the task; and he therefore acquiesced in this answer, for he was convinced of its truth in his own case also.