 In this case too Protagoras has some arguments on his side. Up until this point, the discussion has centred on the problem of “truth”, a concept the importance of which can hardly be disputed. However, no matter how central it may be, truth is not the only criterion that governs human thoughts and actions. Alongside truth there are other, equally important criteria, as the sophist argues in the so-called “Protagoras’ Apology” (166a–168c = 80A21a DK; the Theaetetus takes place in 399 BCE, the year of Socrates’ trial, by which time Protagoras had already passed away; this is the answer Protagoras would have given to Socrates, had he been present at the dialogue: it is not a fragment but it probably conveys some of his views). In his fictional reply, Protagoras distinguishes between knowledge and wisdom (sophia). Unlike knowledge and truth, wisdom varies. From the point of view of knowledge and truth, every individual is a measure, and the fact that each person is a measure depends on his relationship with reality he or she is experiencing—this is a fact. But from the point of view of the value of the contents (of wisdom), it cannot be ruled out that some people are capable of allowing the individual to establish a more expedient relationship with reality. 