Vague and mysterious forms of speech, and abuse of language, have so long passed for mysteries of science; and hard or misapplied words with little or no meaning have, by prescription, such a right to be mistaken for deep learning and height of speculation, that it will not be easy to persuade either those who speak or those who hear them, that they are but the covers of ignorance and hindrance of true knowledge.
John LockeAll men are liable to error; and most men are, in many points, by passion or interest, under temptation to it.
John LockeA young man before he leaves the shelter of his father's house, and the guard of a tutor, should be fortify'd with resolution, and made acquainted with men, to secure his virtues, lest he should be led into some ruinous course, or fatal precipice, before he is sufficiently acquainted with the dangers of conversation, and his steadiness enough not to yield to every temptation.
John Locke