Abstract

It is commonly said that ethical disputes either involve disagreements of fact or disagreements of principle and that while disagreements of fact can be overcome by rational means, disagreements of principle cannot. The difficulty is supposed to be this: for an argument to be rationally persuasive it must appeal to premises already accepted by the person to be persuaded, and if the premises include the principle in question then they will not be acceptable to that person; however, if the premises do not include the principle in question the argument cannot succeed because the conclusion can only validly be inferred from premises which do include the principle in question. While this doctrine is appealing to philosophers who find the idea of ultimate disagreement in ethics comforting, it is a visciously skeptical view which can be generalized to cover all systematic areas of human knowledge. As ‘disagreements of principle’ can appear in almost any domain of human inquiry, the hidden cost of this doctrine is terribly high.