" It is hard to know what other way men can come at truth, to lay hold of it, if they do not dig and search for it as for gold and hid treasure; but he that
does so must have much earth and rubbish before he gets the pure metal; sand, and pebbles, and dross usually lie blended with it, but the gold is nevertheless gold, and will enrich the man that employs his pains to seek and separate it. "

― , Locke's Conduct of the Understanding