Some scholars believe Plato intended to write a trilogy consisting of Politikos (later period, 365-361 b.c.e.; Statesman, 1804), the Sophist, and a third dialogue on the philosopher. Because the first two dialogues search for definitions that not only will delimit the statesman and the Sophist but also will show how, if at all, they differ from the philosopher, it seems likely that Plato planned a third dialogue in which he would define the philosopher and describe the appropriate search for knowledge. In the Sophist, Plato defines Sophists and describes the kind of activity that properly belongs to them. The dialogue Theaettos (middle period, 388-368 b.c.e.; Theaetetus, 1804) is also intimately connected to this series, for in it Plato begins the quest for a proper definition of knowledge and for an answer to many of the problems that plagued him as he worked out his theory of ideas. The Sophist follows Theaetetus and carries on the search for an answer.

The Sophist Defined

In attempting to define “sophist,” Plato makes use of the technique of classification by which he goes from the most general terms to the more specific. He makes use of a similar approach in the Statesman in order to distinguish the true ruler from apparent ones. In their pursuit of the nature of Sophists, Socrates and a stranger from Elea point out many facets of their character, especially with regard to what they profess to know, which indicate to them that although a correct definition ought to point to that, and that alone, which is essential to the nature of Sophists, they find that they profess to be master of many arts.

The Sophists’ most pronounced trait is the ability to discourse persuasively; they claim that through the art of rhetoric, they can give one knowledge in all fields. It is denied by the stranger that one can have knowledge in all fields, a denial in accord with Plato’s view expressed throughout his works and emphasized in Politeia (middle period, 388-368 b.c.e.; Republic, 1701) that one can know and do only one thing well. Therefore, Sophists, although they proclaim themselves experts in many areas, must have and present only the appearance or image of a subject rather than the reality. Sophistry, if it is an art (for how can the practitioners of sham be artists?), is the art of image making. The stranger then pursues an analysis of image making.

Reality and Appearance

Image making has two parts or kinds. First, one may copy an original; examples are the craftsperson who copies a natural object and the painter who makes a likeness of someone’s face. Second, there are those who make semblances—what appear to be likenesses but are in some way out of proportion. The second type of image making raises certain questions. What is meant by this world of semblances? A semblance is apparently not real, and yet it cannot be said to be unreal or nothing, for it is something. However, what kind of a something? Plato is again struggling with the Parmenidean problem of the existence of a world of appearances, which is neither of the world of forms or ideas nor of the world of not-being or nothing; rather, it seems to hover somewhere in between, to be a world of change, of becoming.

The Eleatic stranger had previously proclaimed himself, or had been proclaimed, a student of Zeno and of Parmenides, and he shows his indebtedness to them in his pursuit of these questions. The concern over the world of appearances brings up related problems over the judgments made about that world. For in dealing with that which is not real (that is, that which changes), one must use negative judgments, yet these judgments apparently refer to some object. Plato is emphasizing that when one uses a locution such as “is not,” one seems to be denying the existence of something. However, of what? There is nothing that one can be talking about because apparently it, whatever it is, is not, and hence is not anything. This sort of puzzle sets off a discussion in the Sophist over certain aspects of epistemology and ontology that had troubled pre-Socratic philosophers and to which Plato addressed himself. The discussion concerns the three realms of not-being (nothing), becoming, and being, and what sort of knowledge and judgment is appropriate to each.

In discussing the worlds of reality and appearance, the stranger dismisses rather quickly that of not-being or the totally unreal. Generally speaking, the totally unreal cannot be the subject of discourse because one’s statements cannot have...

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Idealism vs. Materialism

The discovery of the unsatisfactory character of Parmenides’ view of reality leads to a general discussion of idealism versus materialism as philosophical positions; Plato picturesquely calls this “the battle between the Gods and Giants,” between those who dwell in the heavens—the realm of ideas—versus those who dwell on the earth—the realm of the tangible. The Giants, or materialists, claim that only the tangible is real, whereas the idealists, or Gods, point out that moral qualities can be present in some and absent in others; these are qualities that are not tangible yet must be admitted as real. The question as to what is real leads both camps to search for a mark or sign by which they may know the real. The materialists suggest, and the Eleatic stranger considers it tentatively, that only that which has the power to affect or to be affected by an agent is the real. The Eleatic stranger makes out the following objection to the materialists: The materialists demand a quality that they can sense before they proclaim something real; they admit, however, that they can be aware of the presence or absence of “justice” within themselves or others; but such awareness is not of a sensible quality but of an intellectual one, and its object, justice, is an idea.

In discussing the idealists, the Eleatic stranger first considers the view that proclaims that only that which is changeless can be an object of knowledge and truly real. However, can the changeless be an object of knowledge if to know is to act on in some sense? For if that which is an object of knowledge is acted on,...

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Movement, Rest, and Reality

The Eleatic stranger then considers the questions raised in the discussion, questions concerning the possibility of the combination of forms and of negative judgments. The forms considered in this discussion are movement, rest, and reality (or existence). Some forms must be compatible with others in that some kind of combination must be possible between them if they are to be said to be real. Thus, unless movement combines with reality and unless rest does also, neither of them is real. Not all forms are compatible in this way, however, or else we would run into absurdities; for instance, movement cannot combine with rest, for if it did then we could say of movement that it is at rest, and of rest that it is in movement. The task of philosophers in their search for wisdom and truth is to investigate which forms combine and which do not; this task is to be accomplished by philosophic discourse—by dialectic. The Eleatic stranger reminds his cohorts in discussion that their task is to seek out the Sophist, who dwells in the realm of seeming or perhaps of not-being, rather than the philosopher. He suggests that after their present task is finished, they may come back to philosophers and their realm (thus giving credence to the view that Plato intended to write a dialogue on the philosopher). In the search for what is real, the purpose is to clarify the realm that the Sophist inhabits.

The stranger continues this discussion by bringing up two more forms: sameness and difference. He does so because in speaking of two or more forms, we are automatically...

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False Statements and Judgments

The Eleatic stranger presents an analysis of statements (essentially of descriptive statements) to clarify the problem of false judgments. Of every statement, it may be said that it must contain at least a name (an expression applied to that which performs the action) and a verb (an expression applied to the action). Every statement must also be about something. Lastly, every statement has a certain character; that is, we say of it that it is either true or false. The examples that the stranger considers are “Theaetetus sits” and “Theaetetus flies.” The first is true for Theaetetus is in fact sitting. The second is false for it describes the subject Theaetetus as doing what he is not doing. Thus it states that things that...

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Additional Reading

Brumbaugh, Robert S. Plato for the Modern Age. New York: Crowell-Collier, 1962. A good introduction to Plato’s thought and the Greek world in which he developed it.

Copleston, Frederick. A History of Philosophy: Greece and Rome. Garden City, N.Y.: Doubleday, 1969. Copleston devotes several clear chapters to a discussion of the full range of Plato’s view.

Cropsey, Joseph. Plato’s World: Man’s Place in the Cosmos. Chicago: University of Chicago Press, 1995. Discusses Plato’s views on human nature with attention to his political theories.


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