If a man will begin with certainties, he shall end in doubts; but if he will be content to begin in doubts, he shall end in certainties.

Francis Bacon (1561-1626) English philosopher, scientist, author, statesman

De Augmentis Scientiarum [Advancement of Learning], Book 1, ch. 5, sec. 8 (1605)

Alt trans. (Willey Book ed., (1944)): "If we begin with certainties, we shall end in doubts; but if we begin with doubts, and are patient with them, we shall end in certainties."