e were to ask you: With what does a man see black
and white colours? and with what does he hear high and low sounds?--you
would say, if I am not mistaken, 'With the eyes and with the ears.'

THEAETETUS: I should.

SOCRATES: The free use of words and phrases, rather than minute
precision, is generally characteristic of a liberal education, and
the opposite is pedantic; but sometimes precision is necessary, and I
believe that the answer which you have just given is open to the charge
of incorrectness; for which is more correct, to say that we see or hear
with the eyes and with the ears, or through the eyes and through the
ears.

THEAETETUS: I should say 'through,' Socrates, rather than 'with.'

SOCRATES: Yes, my boy, for no one can suppose that in each of us, as
in a sort of Trojan horse, there are perched a number of unconnected
senses, which do not all meet in some one nature, the mind, or whatever
we please to call it, of which they are the instruments, and with which
through them we perceive objects of sense.

THEAETETUS: I agree with you in that opinion.

SOCRATES: The reason why I am thus precise is, because I want to know
whether, when we perceive black and white through the eyes, and again,
other qualities through other organs, we do not perceive them with one
and the same part of ourselves, and, if you were asked, you might refer
all such perceptions to the body. Perhaps, however, I had better allow
you to answer for yourself and not interfere. Tell me, then, are not
the organs through which you perceive warm and hard and light and sweet,
organs of the body?

THEAETETUS: Of the body, certainly.

SOCRATES: And you would admit that what you perceive through one
faculty you cannot perceive through another; the objects of hearing,
for example, cannot be perceived through sight, or the objects of sight
through hearing?

THEAETETUS: Of course not.

SOCRATES: If you have any thought about both of them, this common
perception cannot come to you, either through the one or the other
organ?

THEAETETUS: It cannot.

SOCRATES: How about sounds and colours: in the first place you would
admit that they both exist?

THEAETETUS: Yes.

SOCRATES: And that either of them is different from the other, and the
same with itself?

THEAETETUS: Certainly.

SOCRATES: And that both are two and each of them one?

THEAETETUS: Yes.

SOCRATES: You can further observe whether they are like or unlike one
another?

THEAE