Capitalism is the extraordinary belief that the nastiest of men for the nastiest of motives will somehow work together for the benefit of all. - John Maynard Keynes
Yeah, this is not definitely attributed to Keynes, and earlier verions of it by other people paint this in a slightly different way as a positive point, that even nasty people work for the benefit of all. Many versions have been attributed to Keynes, both as a positive and a negative for capitalism.