"man's insanity is heaven's sense"

In Moby Dick, there is a character, Pip, who goes mad from having been thrown overboard and abandoned to the sea in the heat of a whale-chase. Melville describes Pip as having been transported into another world, from which he can never return, like the enlightened who leave Plato's cave:

By the merest chance the ship itself at last rescued him; but from that hour the little negro went about the deck an idiot; such, at least, they said he was. The sea had jeeringly kept his finite body up, but drowned the infinite of his soul. Not drowned entirely, though. Rather carried down alive to wondrous depths, where strange shapes of the unwarped primal world glided to and fro before his passive eyes; and the miser-merman, Wisdom, revealed his hoarded heaps; and among the joyous, heartless, ever-juvenile eternities, Pip saw the multitudinous, God-omnipresent, coral insects, that out of the firmament of waters heaved the colossal orbs. He saw God's foot upon the treadle of the loom, and spoke it; and therefore his shipmates called him mad. So man's insanity is heaven's sense; and wandering from all mortal reason, man comes at last to that celestial thought, which, to reason, is absurd and frantic; and weal or woe, feels then uncompromised, indifferent as his God. (Moby Dick, chap. 93. New York: Signet, 1961: 396-7.)