After a digression, Socrates turns to a more serious criticism of the position of Protagoras, one that takes into account the justification Socrates has offered on behalf of Protagoras. Socrates is quite willing to admit that the Protagorean position is a fair account of what occurs in immediate sensation. The world of becoming, for Plato and Socrates, is a flux, and people’s sensations are private. One cannot taste the apple another person is tasting, nor does one ever see a particular apple tree from quite the same perspective as that of one’s companion. The “seeming” of the immediate data of sense is the “reality” of the immediate data of sense. However, the problem of knowledge is wider than the problem of data.
A theory of knowledge must account for other judgments besides those concerning the immediate data of sense, and it is this fact that finally undercuts the Protagorean theory. Once one recognizes that there is more to the problem of knowing than merely giving an account of the direct awareness of uninterpreted sense experience, the weakness of the Protagorean position becomes obvious. Socrates raises the question of justifying judgments that have a future reference; thus, he broadens the scope of the discussion to include a problem Protagoras’s theory cannot explain. A physician and his patient, for example, may disagree today about whether the patient will have a fever tomorrow. It is clear that both cannot be judging truly, and obviously the physician’s prediction is more reliable than is the patient’s. Both are judging about a fact that is not at the moment a part of the immediate...
(The entire section is 665 words.)