the dialectical faculty
withdrawing from sense arrives by the pure intellect at the
contemplation of the idea of good, and never rests but at the very end
of the intellectual world. And the royal road out of the cave into
the light, and the blinking of the eyes at the sun and turning to
contemplate the shadows of reality, not the shadows of an image
only--this progress and gradual acquisition of a new faculty of sight by
the help of the mathematical sciences, is the elevation of the soul to
the contemplation of the highest ideal of being.

'So far, I agree with you. But now, leaving the prelude, let us proceed
to the hymn. What, then, is the nature of dialectic, and what are the
paths which lead thither?' Dear Glaucon, you cannot follow me here.
There can be no revelation of the absolute truth to one who has not been
disciplined in the previous sciences. But that there is a science of
absolute truth, which is attained in some way very different from
those now practised, I am confident. For all other arts or sciences are
relative to human needs and opinions; and the mathematical sciences are
but a dream or hypothesis of true being, and never analyse their own
principles. Dialectic alone rises to the principle which is above
hypotheses, converting and gently leading the eye of the soul out of the
barbarous slough of ignorance into the light of the upper world, with
the help of the sciences which we have been describing--sciences, as
they are often termed, although they require some other name, implying
greater clearness than opinion and less clearness than science, and this
in our previous sketch was understanding. And so we get four names--two
for intellect, and two for opinion,--reason or mind, understanding,
faith, perception of shadows--which make a proportion--
being:becoming::intellect:opinion--and science:belief::understanding:
perception of shadows. Dialectic may be further described as that
science which defines and explains the essence or being of each nature,
which distinguishes and abstracts the good, and is ready to do battle
against all opponents in the cause of good. To him who is not a
dialectician life is but a sleepy dream; and many a man is in his grave
before his is well waked up. And would you have the future rulers of
your ideal State intelligent beings, or stupid as posts? 'Certainly not
the latter.' Then you must train them in dialectic, which will teach
them to ask and answer questions, and is the