Every man is not ambitious, or courteous, or passionate; but every man has pride enough in his composition to feel and resent the least slight and contempt. Remember, therefore, most carefully to conceal your contempt, however just, wherever you would not make an implacable enemy. Men are much more unwilling to have their weaknesses and their imperfections known, than their crimes; and if you hint to a man that you think him silly, ignorant, or even ill-bred, or awkward, he will hate you more and longer, than if you tell him plainly, that you think him a rogue.

Lord Chesterfield (1694-1773) English statesman, wit [Philip Dormer Stanhope]

Letter to his son, #161 (5 Sep 1748)
    (Source)