Sub-session 5 Moral Objectivity, Truth and Justification
Quite some moral norms appear to be common to all human cultures. Starting with Darwin’s Descent of Man, the existence of such moral universals has been explained convincingly by evolutionary mechanisms. This sub-session is devoted to the question how we should conceive of the objectivity, truth, and justification of our moral beliefs in the light of these evolutionary explanations. For example, is a cognitivist version of Kantian constructivism compatible with evolutionary explanations of moral universals? Should we construe moral truth in terms of correspondence, as moral realists do, or differently? What is the most plausible model of moral justification?
The Argument from Agreement
The most popular argument against moral realism is the argument from disagreement: if there are mind-independent moral facts, then we would not expect to find as much moral disagreement as we in fact do; therefore, moral realism is false. In this paper, I develop the flipside of this argument. According to my argument from agreement, we would expect to find lots of moral disagreement if there were mind-independent moral facts. But we do not, in fact, find much moral disagreement; therefore, moral realism is false. I defend the argument, explain the empirical evidence that supports it, and show what makes this challenge novel and powerful.
Truth in Ethics and Elsewhere: The Criterial Conception
In ordinary language, we call beliefs and statements ‘true’ or ‘false’. To most of us, there does not seem to be any lack of clarity about what we mean when we are doing so. Is it not astonishing, then, that philosophers developed so many different theories of truth, and disagree about the truth of these theories? One of the contentious issues in this area is whether moral statements can be true or false, and if so, in which sense. For example, do evolutionary debunking arguments succeed in showing that all truth-claims in ethics are problematic? The main objective of the paper is to develop a general account of truth, and of its application to the moral domain, which does justice to considerations that motivated philosophers to develop so many competing conceptions. On the basis of this account one will understand what went wrong in philosophical theory-construction on truth. The set-up of the paper is as follows. The criterial conception of truth is sketched in §2. I remind the reader of some classic debates in meta-ethics on whether moral statements can be true in §3, and formulate five requirements that an account of moral truth has to meet. Section 4 examines critically the usual dimensions of contemporary theories of truth. In §5, my criterial conception is developed, and illustrated by defining criteria for the truth of empirical and arithmetical statements. Finally, criteria of moral truth are argued for in section 6, taking into account an evolutionary explanation of moral universals.