In describing the character and motivations of one Mr. Osborne toward a certain Mr. Sedley:
One of the great conditions of anger and hatred is, that you must tell and believe lies against the hated object, in order, as we said, to be consistent.
This is interesting for other reasons also, in that the motivation to be consistent is important and far reaching in its ability to modify our actions as human beings. This particular hook into our minds is discussed in the book, Influence: the Psychology of Persuasion which I had the opportunity to read recently.