Jasper Fforde said this quote

The best reason for committing loathsome and detestable acts--and let's face it, I am considered something of an expert in this field--is purely for their own sake. Monetary gain is all very well, but it dilutes the taste of wickedness to a lower level that is obtainable by anyone with an overdeveloped sense of avarice. True and baseless evil is as rare as the purest good--and we all know how rare that is...