The real trouble is that "kindness" is a quality fatally easy to attribute to ourselves on quite inadequate grounds. Everyone feels benevolent if nothing happens to be annoying him at the moment. Thus a man easily comes to console himself for all his other vices by a conviction that "his heart's in the right place" and "he wouldn't hurt a fly," though in fact he has never made the slightest sacrifice for a fellow creature. We think we are kind when we are only happy: it is not so easy, on the same grounds, to imagine oneself temperate, chaste, or humble.
C. S. Lewis, The Problem of Pain, Collier (New York: 1962) p. 56.