republic (books 6 - 10)
ble can also be eternal and subject to no deviation--that would
be absurd; and it is equally absurd to take so much pains in
investigating their exact truth.
I quite agree, though I never thought of this before.
Then, I said, in astronomy, as in geometry, we should em-
ploy problems, and let the heavens alone if we would approach
the subject in the right way and so make the natural gift of
reason to be of any real use.
That, he said, is a work infinitely beyond our present astron-
Yes, I said; and there are many other things which must also
have a similar extension given to them, if our legislation is to
be of any value. But can you tell me of any other suitable
No, he said, not without thinking.
Motion, I said, has many forms, and not one only; two of
them are obvious enough even to wits no better than ours; and
there are others, as I imagine, which may be left to wiser per-
But where are the two?
There is a second, I said, which is the counterpart of the one
And what may that be?
The second, I said, would seem relatively to the ears to be
what the first is to the eyes; for I conceive that as the eyes are
designed to look up at the stars, so are the ears to hear harmo-
nious motions; and these are sister sciences--as the Pythago-
reans say, and we, Glaucon, agree with them?
Yes, he replied.
But this, I said, is a laborious study, and therefore we had
better go and learn of them; and they will tell us whether there
are any other applications of these sciences. At the same time,
we must not lose sight of our own higher object.
What is that?
There is a perfection which all knowledge ought to reach,
and which our pupils ought also to attain, and not to fall short
of, as I was saying that they did in astronomy. For in the
science of harmony, as you probably know, the same thing hap-
pens. The teachers of harmony compare the sounds and con-
sonances which are heard only, and their labor, like that of the
astronomers, is in vain.
Yes, by heaven! he said; and 'tis as good as a play to hear
them talking about their condensed notes, as they call them;
they put their ears close alongside of the strings like persons
catching a sound from their neighbor's wall--one set of them
declaring that they distinguish an intermediate note and have
found the least interval which should be the unit of measure-
ment; the others insisting that the two sounds have passed into
the same--either party setting their ears before their under-