A sensible man will remember that the eyes may be confused in two ways – by a change from light to darkness or from darkness to light; and he will recognize that the same thing happens to the soul. – Plato

I keep the subject of my inquiry constantly before me, and wait till the first dawning opens gradually, by little and little, into a full and clear light. – Sir Isaac Newton

Light, when suddenly let in, dazzles and hurts and almost blinds us: but this soon passes away, and it seems to become the only element we can exist in. – Augustus William Hare and Julius Charles Hare, Guesses at Truth, by Two Brothers

A man should learn to detect and watch that gleam of light which flashes across his mind from within. – Ralph Waldo Emerson