Melville on Doubt

And how nobly it raises our conceit of the mighty, misty monster, to behold him solemnly sailing through a calm tropical sea; his vast, mild head overhung by a canopy of vapor, engendered by his incommunicable contemplations, and that vapor—as you will sometimes see it—glorified by a rainbow, as if Heaven itself had put its seal upon his thoughts. For d’ye see, rainbows do not visit the clear air; they only irradiate vapor. And so, through all the thick mists of the dim doubts in my mind, divine intuitions now and then shoot, enkindling my fog with a heavenly ray. And for this I thank God; for all have doubts; many deny; but doubts or denials, few along with them, have intuitions. Doubts of all things earthly, and intuitions of some things heavenly; this combination makes neither believer nor infidel, but makes a man who regards them both with equal eye.

–Herman Melville, Moby Dick, ch. 85 (1851) in the Library of America ed., p. 1193.