Stephen Schiffer

I’m going to argue for something that some of you will find repugnant but which I can’t help thinking may be true—namely, that there are no determinate moral truths. As will become apparent, my interest in moral discourse as manifested in this paper derives more than a little from my interest in the theory of meaning. Moral discourse has always presented a puzzle for the theory of meaning and philosophical logic, and I take myself to be following the advice of Bertrand Russell when he recommended testing philosophical theories by their capacity to deal with puzzles, “since these serve much the same purpose as is served by experiments in physical science.” Section (1) offers an epistemological argument for the claim that there are no determinate moral truths. This argument raises further questions, which subsequent sections try to answer. In the course of answering those further questions, another, non-epistemological, argument is offered for the claim that there are no determinate moral truths. In the end, I hope we see not only that there are no determinately true moral propositions, but what it is about moral concepts which makes that so

Suppose we think in a language of thought. Then Paul Boghossian' is prepared to argue, first, that there may be ambiguous Mentalese expression types that have unambiguous tokens, and, second, that the way in which this is possible allows for otherwise valid theoretical or practical reasoning to be rendered invalid owing to equivocation of a sort that may be undetectable to the reasoner. Paul sees this as a possible basis from which to launch an argument for what some might call "narrow content", and this is a question I'll take up later