All schools, all colleges, have two great functions: to confer, and to conceal, valuable knowledge. The theological knowledge which they conceal cannot justly be regarded as less valuable than that which they reveal. That is, when a man is buying a basket of strawberries it can profit him to know that the bottom half of it is rotten.

Mark Twain and the three R's: race, religion, revolution--and related matters (ed. Bobbs-Merrill Company, 1973)