ubject, produce the same, or become
similar, for that too would produce another result from another subject,
and become different.

THEAETETUS: True.

SOCRATES: Neither can I by myself, have this sensation, nor the object
by itself, this quality.

THEAETETUS: Certainly not.

SOCRATES: 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 no
one.

THEAETETUS: Certainly not.

SOCRATES: 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.

THEAETETUS: Very true, Socrates.

SOCRATES: Then, if that which acts upon me has relation to me and to no
other, I and no other am the percipient of it?

THEAETETUS: Of course.

SOCRATES: 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.

THEAETETUS: I suppose so.

SOCRATES: 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
perceive?

THEAETETUS: You cannot.

SOCRATES: 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 new-born
child, of which I have delivered you? What say you?

THEAETETUS: I cannot but agree, Socrates.

SOCRATES: 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 rea