Precis of Part Two

Abstract

The idea of moral objectivity seems to me best construed as follows: it is possible to find out about some moral sentences that they are true. Under that construal, the idea is an epistemological thesis. has further consequences, however: accepting it constrains what can count as an acceptable metaphysics of morality and as a plausible account of the nature of moral discourse. take moral scepticism to be the negation of the idea of moral objectivity. The moral sceptic says it is not possible to find out about any moral sentences that they are true. In Chapters 6 and 7 of Harman's and my book, discussed arguments for moral skepticism. Chapter 6 is primarily concerned with an epistemological argument for moral skepticism. Suppose we accept (i) the truth of a sentence S is evidence for a sentence T just in case the truth of T would explain the truth of S. (Thus the truth of It seems to me now that am sitting in front of a is evidence for I am sitting in front of a since its actually being the case that am sitting in front of a fire would explain its seeming to me that am.) Suppose we also accept (ii) there is no moral sentence whose truth would explain the truth of any factual sentence. follows that there is no factual sentence whose truth is evidence for any moral sentence. Suppose we also accept (iii) we can only find out that some moral sentence M is true by finding out that some factual sentence is true, whose truth is evidence for M. follows that we cannot find out about any moral sentence that it is true. Some people have argued that this argument fails because (ii) is false. surveyed, and rejected, their arguments. will not summarize my grounds for doing so here: two of the critics argue against me on this point, and will return to it in my Reply to Critics. said that the argument fails because (i) is false. The truth of