The greatest evil is not now done in those sordid "dens of crime" that Dickens loved to paint. It is not even in concentration camps and labour camps. In those we see its final result. But it is conceived and ordered (moved, seconded, carried, and minuted) in clean, carpeted, warmed, and well-lighted offices, by quiet men with white collars and cut fingernails and smooth shaven cheeks who do not need to raise their voice.

-C.S. Lewis, The Screwtape Letters  

[Incidentally, a piece of interesting trivia: this quote was quoted in one of the most famous presidential speeches in history, Reagan's "evil empire" speech. In fact, it was this quote which led into his denouncing the Soviet Union as the "evil empire"]

http://youtu.be/do0x-Egc6oA?t=2m29s