There is no steady unretracing progress in this life; we do not advance through fixed gradations, and at the last one pause:—through infancy’s unconscious spell, boyhood’s thoughtless faith, adolescence’ doubt (the common doom), then scepticism, then disbelief, resting at last in manhood’s pondering repose of If. But once gone through, we trace the round again; and are infants, boys, and men, and Ifs eternally. Where lies the final harbor, whence we unmoor no more?
—Herman Melville, Moby Dick. “CHAPTER 114. The Gilder.”