If one claims that something is morally wrong but feels no disinclination to do it or to persuade others not to do it, then one is either being insincere or not making a genuine moral claim.

Premise (1) appears to follow directly from the nature of knowledge. If one knows that something is the case, then one must have some belief or judgment about it and what one believes must truly be the case. If one doesn’t have any opinion about it or if one’s opinion about it is not true, then one doesn’t know it. To say this much, of course, is not to say that true opinion is sufficient for knowledge, but that one’s judgment is true has seemed to many philosophers to be a minimally necessary c