Here are some quotes from Plato’s Dialogue, “Sophist”. I have spent a good deal of time in discussions with modern wise men. Sometimes one is tempted to think that the issues in contention are current topics and challenges; appearing uniquely in “our” time. I was amazed to find that Theaetetus had the same experience in his conversation with the “Visitor”; forced to face the same trials. Socrates barely speaks in this dialogue, leaving the young Theaetetus to be lead along by the mysterious stranger from Elea.
From Sophist on Dichotomous Logic, (The method of reasoning, taught in modern university philosophy programs, based on the assumption that each constraint in a problem can be judged as either true or false; providing for a branching decision tree leading us to some “identification”.) of T’s and F’s:
Visitor: So now we’re in agreement about the angler’s expertise, not just as to its name; in addition we’ve also sufficiently grasped a verbal explanation concerning the thing itself. Within expertise as a whole one half was acquisitive; half of the acquisitive was taking possession; half of possession-taking was aquatic hunting; all of the lower portion of aquatic hunting was fishing; half of fishing was hunting by striking; and half of striking was hooking. And the part of hooking that involves a blow drawing a thing upward from underneath is called by a name that’s derived by its similarity to the action itself, that is, it’s called draw-fishing or angling—which is what we’re searching for. p. 241
From Sophist on Ignorance:
Visitor: Not knowing, but thinking that you know. That’s what probably causes all the mistakes we make when we think. p. 250
From Sophist on How to Teach:
Visitor: . . . Doctors who work on the body think it can’t benefit from any food that’s offered to it until what’s interfering with it from inside is removed. The people who cleanse the soul, my young friend, likewise think the soul, too, won’t get any advantage from any learning that’s offered to it until someone shames it by refuting it, removes the opinions that interfere with learning, and exhibits it cleansed, believing that it knows only those things that it does know, and nothing more. p. 251
From Sophist on Bad Teachers:
Visitor: Well then, won’t we expect that there’s another kind of expertise—this time having to do with words—and that someone can use it to trick young people when they stand even farther away from the truth about things? Wouldn’t he do it by putting words in their ears, and by showing them spoken copies of everything, so as to make them believe that the words are true and that the person who’s speaking to them is the wisest person there is? p. 255
From Sophist on Having Courage to Question:
Visitor: So that’s why we have to be bold enough to attack what our father [Parmenides] says. Or, if fear keeps us from doing that, then we’ll have to leave it alone completely.
Theaetetus: Fear, anyway, isn’t going to stop us.
From Sophist on 1 + 1 = 3:
Visitor: You understand exactly, Theaetetus. I’m saying we have to follow the track this way. Let’s ask—as if they were here—“Listen, you people who say that all things are just some two things, hot and cold or some such pair. What are you saying about them both when you say that they both are and each one is? What shall we take this being to be? Is it a third thing alongside those two beings, so that according to you everything is no longer two but three? Surely in calling one or the other of the two of them being, you aren’t saying that they both are, since then in either case they’d be one and not two.” pp. 264-265
From Sophist on the Sum of the Parts = the Whole:
Visitor: But if a thing has parts then nothing keeps it from having the characteristic of being one in all its parts, and in that it’s all being and it’s also one whole. p. 266
From Sophist on Grammar, Nouns and Verbs:
Visitor: One kind is called names, and the other is called verbs.
Theaetetus: Tell me what each of them is.
Visitor: A verb is the sort of indication that’s applied to things that perform the actions.
Visitor: And a name is the kind of spoken sign that’s applied to things that perform the actions.
Visitor: So no speech is formed just from names spoken in a row, and also not from verbs that are spoken without names. p. 285
From Sophist on Though and Speech Being the Same:
Visitor: Aren’t thought and speech the same, except that what we call thought is speech that occurs without the voice, inside the soul in conversation with itself? p. 287
From Sophist on Belief:
Visitor: So when affirmation or denial occurs as silent thought inside the soul, wouldn’t you call that belief?
Theaetetus: Of course.
From Sophist on Appearance – Both the False and the True:
Visitor: So since there is true and false speech, and of the processes just mentioned, thinking appeared to be the soul’s conversation with itself, belief the conclusion of thinking, and what we call appearing the blending of perception and belief, it follows that since these are all the same kind of thing as speech, some of them must sometimes be false. p. 288
From Sophist on Creation and Intelligent Design – v – Spontaneous Generation and Evolution:
Visitor: Take animals and everything mortal, including plants and everything on the earth that grows from seeds and roots, and also all lifeless bodies made up inside the earth, whether fusible [capable of being melted] or not. Are we going to say that anything besides the craftsmanship of a god makes them come to be after previously not being? Or shall we rely on the saying and the widespread belief that . . ?
Theaetetus: That what?
Visitor: Are we going to say that nature produces them by some spontaneous cause that generates them without any thought, or by a cause that works by reason and divine knowledge derived from a god? p. 289