In Book VII of Plato’s Republic, Socrates tells Glaucon that they have reached “the hymn of dialectic”, which proceeds “by the light of reason only” to “the absolute”. It follows the image of the cave and the account of the studies that prepare for dialectic. The passage stands under the ascent to first principles for its figure of the discovery of “the absolute” by reason alone.
Read in contextAnd so, Glaucon, I said, we have at last arrived at the hymn of dialectic. This is that strain which is of the intellect only, but which the faculty of sight will nevertheless be found to imitate; for sight, as you may remember, was imagined by us after a while to behold the real animals and stars, and last of all the sun himself. And so with dialectic; when a person starts on the discovery of the absolute by the light of reason only, and without any assistance of sense, and perseveres until by pure intelligence he arrives at the perception of the absolute good, he at last finds himself at the end of the intellectual world, as in the case of sight at the end of the visible.
Exactly, he said.
Then this is the progress which you call dialectic?
True.