A great quote from R.A. Lafferty, one of the old great SF short-story authors.

Things are set up as contraries that are not even in the same category. Listen to me: the opposite of radical is superficial, the opposite of liberal is stingy; the opposite of conservative is destructive. Thus I will describe myself as a radical conservative liberal; but certain of the tainted red fish will swear that there can be no such fish as that. Beware of those who use words to mean their opposites. At the same time have pity on them, for usually this trick is their only stock in trade.

Pillaged from this comment thread.