THEAETETUS [41]
enumeration of the hundred planks, adds rational explanation to true
opinion, and instead of opinion has art and knowledge of the nature of
a waggon, in that he attains to the whole through the elements.
Theaet. And do. you not agree in that view, Socrates?
Soc. If you do, my friend; but I want to know first, whether you
admit the resolution of all things into their elements to be a
rational explanation of them, and the consideration of them in
syllables or larger combinations of them to be irrational-is this your
view?
Theaet. Precisely.
Soc. Well, and do you conceive that a man has knowledge of any
element who at one time affirms and at another time denies that
clement of something, or thinks that. the same thing is composed of
different elements at different times?
Theaet. Assuredly not.
Soc. And do you not remember that in your case and in of others this
often occurred in the process of learning to read?
Theaet. You mean that I mistook the letters and misspelt the
syllables?
Soc. Yes.
Theaet. To be sure; I perfectly remember, and I am very far from
supposing that they who are in this condition, have knowledge.
Soc. When a person, at the time of learning writes the name of
Theaetetus, and thinks that he ought to write and does write Th and e;
but, again meaning to write the name of Theododorus, thinks that he
ought to write and does write T and e-can we suppose that he knows the
first syllables of your two names?
Theaet. We have already admitted that such a one has not yet
attained knowledge.
Soc. And in like manner be may enumerate without knowing them the
second and third and fourth syllables of your name?
Theaet. He may.
Soc. And in that case, when he knows the order of the letters and
can write them out correctly, he has right opinion?
Theaet. Clearly.
Soc. But although we admit that he has right opinion, he will
still be without knowledge?
Theaet. Yes.
Soc. And yet he will have explanations, as well as right opinion,
for he knew the order of the letters when he wrote; and this we
admit be explanation.
Theaet. True.
Soc. Then, my friend, there is such a thing as right opinion
united with definition or explanation, which does not as yet attain to
the exactness of knowledge.
Theaet. It would seem so.
Soc. And what we fancied to be a perfect definition of knowledge
is a dream only. But perhaps we had better not say so as yet, for were
there not three explanations of knowledge, one of which must, as we
said, be adopted by him who maintains knowledge to be true opinion
combined with rational explanation? And very likely there may be found
some one who will not prefer this but the third.
Theaet. You are quite right; there is still one remaining. The first
was the image or expression of the mind in speech; the second, which
has just been mentioned, is a way of reaching the whole by an
enumeration of the elements. But what is; the third definition?
Soc. There is, further, the popular notion of telling the mark or
sign of difference which distinguishes the thing in question from
all others.
Theaet. Can you give me any example of such a definition?
Soc. As, for example, in the case of the sun, I think that you would
be contented with the statement that the sun is, the brightest of
the heavenly bodies which revolve about the earth.
Theaet. Certainly.
Soc. Understand why:-the reason is, as I was just now saying, that
if you get at the difference and distinguishing characteristic of each
thing, then, as many persons affirm, you will get at the definition or
explanation of it; but while you lay hold only of the common and not
of the characteristic notion, you will only have the definition of
those things to which this common quality belongs.
Theaet. I understand you, and your account of definition is in my
judgment correct.
Soc. But he, who having right opinion about anything, can find out
the difference which distinguishes