is wanting, there is neither.

  Y. Soc. True; and what is the next step?

  Str. The next step clearly is to divide the art of measurement
into two parts, all we have said already, and to place in the one part
all the arts which measure number, length, depth, breadth, swiftness
with their opposites; and to have another part in which they are
measured with the mean, and the fit, and the opportune, and the due,
and with all those words, in short, which denote a mean or standard
removed from the extremes.

  Y. Soc. Here are two vast divisions, embracing two very different
spheres.

  Str. There are many accomplished men, Socrates, who say, believing
themselves to speak wisely, that the art of measurement is
universal, and has to do with all things. And this means what we are
now saying; for all things which come within the province of art do
certainly in some sense partake of measure. But these persons, because
they are not accustomed to distinguish classes according to real
forms, jumble together two widely different things, relation to one
another, and to a standard, under the idea that they are the same, and
also fall into the converse error of dividing other things not
according to their real parts. Whereas the right way is, if a man
has first seen the unity of things, to go on with the enquiry and
not desist until he has found all the differences contained in it
which form distinct classes; nor again should he be able to rest
contented with the manifold diversities which are seen in a
multitude of things until he has comprehended all of them that have
any affinity within the bounds of one similarity and embraced them
within the reality of a single kind. But we have said enough on this
head, and also of excess and defect; we have only to bear in mind that
two divisions of the art of measurement have been discovered which are
concerned with them, and not forget what they are.

  Y. Soc. We will not forget.

  Str. And now that this discussion is completed, let us go on to
consider another question, which concerns not this argument only but
the conduct of such arguments in general.

  Y. Soc. What is this new question?

  Str. Take the case of a child who is engaged in learning his
letters: when he is asked what letters make up a word, should we say
that the question is intended to improve his grammatical knowledge
of that particular word, or of all words?

  Y. Soc. Clearly, in order that he may have a better knowledge of all
words.

  Str. And is our enquiry about the Statesman intended only to improve
our knowledge of politics, or our power of reasoning generally?

  Y. Soc. Clearly, as in the former example, the purpose is general.

  Str. Still less would any rational man seek to analyse the notion of
weaving for its own sake. But people seem to forget that some things
have sensible images, which are readily known, and can be easily
pointed out when any one desires to answer an enquirer without any
trouble or argument; whereas the greatest and highest truths have no
outward image of themselves visible to man, which he who wishes to
satisfy the soul of the enquirer can adapt to the eye of sense, and
therefore we ought to train ourselves to give and accept a rational
account of them; for immaterial things, which are the noblest and
greatest, are shown only in thought and idea, and in no other way, and
all that we are now saying is said for the sake of them. Moreover,
there is always less difficulty in fixing the mind on small matters
than on great.

  Y. Soc. Very good.

  Str. Let us call to mind the bearing of all this.

  Y. Soc. What is it?

  Str. I wanted to get rid of any impression of tediousness which we
may have experienced in the discussion about weaving, and the reversal
of the universe, and in the discussion concerning the Sophist and
the being of not-being. I know that they were felt to be too long, and
I reproached myself with this, fearing that they might be not only
tedious but irrelevant; and all that I have now said is only
designed to prevent the recurrence of any such disagreeables for the
future.

  Y. Soc. Very good. Will you proceed?

  Str. Then I would like to observe that you and I, remembering what
has been said, should praise or blame the length or shortness of
discussions, not by comparing them with one another, but with what
is fitting, having regard to the part of measurement, which, as we
said, was to be borne in mind.

  Y. Soc. Very true.

  Str. And yet, not everything is to be judged even with a view to
what is fitting; for we should only want such a length as is suited to
give pleasure, if at all, as a secondary matter; and reason tells
us, that we should be contented to make the ease or rapidity of an