sick, produces quite another result; which is the sensation of
bitterness in the tongue, and the, motion and creation of bitterness
in and about the wine, which becomes not bitterness but something
bitter; as I myself become not but percipient?
Soc. There is no, other object of which I shall ever have the same
perception, for another object would give another perception, and
would make the perception other and different; nor can that object
which affects me, meeting another, subject, produce, the same, or
become similar, for that too would produce another result from another
subject, and become different.
Soc. Neither can by myself, have this sensation, nor the object by
itself, this quality.
Theaet. Certainly not.
Soc. When I perceive I must become percipient of something-there can
be no such thing as perceiving and perceiving nothing; the object,
whether it become sweet, bitter, or of any other quality, must have
relation to a percipient; nothing can become sweet which is sweet to
Theaet. Certainly not.
Soc. Then the inference is, that we [the agent and patient] are or
become in relation to one another; there is a law which binds us one
to the other, but not to any other existence, nor each of us to
himself; and therefore we can only be bound to one another; so that
whether a person says that a thing is or becomes, he must say that
it is or becomes to or of or in relation to something else; but he
must not say or allow any one else to say that anything is or
becomes absolutely: -such is our conclusion.
Theaet. Very true, Socrates.
Soc. Then, if that which acts upon me has relation to me and to no
other, I and no other am the percipient of it?
Theaet. Of course.
Soc. Then my perception is true to me, being inseparable from my own
being; and, as Protagoras says, to myself I am judge of what is
and-what is not to me.
Theaet. I suppose so.
Soc. How then, if I never err, and if my mind never trips in the
conception of being or becoming, can I fail of knowing that which I
Theaet. You cannot.
Soc. Then you were quite right in affirming that knowledge is only
perception; and the meaning turns out to be the same, whether with
Homer and Heracleitus, and all that company, you say that all is
motion and flux, or with the great sage Protagoras, that man is the
measure of all things; or with Theaetetus, that, given these premises,
perception is knowledge. Am I not right, Theaetetus, and is not this
your newborn child, of which I have delivered you? What say you?
Theaet. I cannot but agree, Socrates.
Soc. Then this is the child, however he may turn out, which you
and I have with difficulty brought into the world. And now that he
is born, we must run round the hearth with him, and see whether he
is worth rearing, or is only a wind-egg and a sham. Is he to be reared
in any case, and not exposed? or will you bear to see him rejected,
and not get into a passion if I take away your first-born?
Theod. Theaetetus will not be angry, for he is very good-natured.
But tell me, Socrates, in heaven's name, is this, after all, not the
Soc. You, Theodorus, are a lover of theories, and now you innocently
fancy that I am a bag full of them, and can easily pull one out
which will overthrow its predecessor. But you do not see that in
reality none of these theories come from me; they all come from him
who talks with me. I only know just enough to extract them from the
wisdom of another, and to receive them in a spirit of fairness. And