It is hard to know what other way men can come to 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.

The Conduct of the Understanding. By J. Locke... Essays... By Lord Bacon. With Sketches of the Lives of Locke and Bacon (ed. 1825)