What decision theory can’t tell us about moral uncertainty

Abstract

We’re often unsure what morality requires, but we need to act anyway. There is a growing philosophical literature on how to navigate moral uncertainty. But much of it asks how to rationally pursue the goal of acting morally, using decision-theoretic models to address that question. I argue that using these popular approaches leaves some central and pressing questions about moral uncertainty unaddressed. To help us make sense of experiences of moral uncertainty, we should shift away from focusing on what it’s rational to do when facing moral uncertainty, and instead look directly at what it’s moral to do about moral uncertainty—for example, how risk averse we morally ought to be, or which personal sacrifices we’re morally obligated to make in order to reduce our risk of moral wrongdoing. And orthodox, expectation-maximizing, decision-theoretic models aren’t well-suited to this task—in part because they presuppose the answers to some important moral questions. For example, if approaching moral uncertainty in a moral way requires us to “maximize expected moral rightness,” that’s, itself, a contentious claim about the demands of morality—one that requires significant moral argument, and that I ultimately suggest is mistaken. Of course, it’s possible to opt, instead, for a variety of alternative decision-theoretic models. But, in order to choose between proposed decision-theoretic models, and select one that is well-suited to handling these cases, we first would need to settle more foundational, moral questions—about, for example, what we should be willing to give up in order to reduce the risk that we’re acting wrongly. Decision theory may be able to formalize the conclusions of these deliberations, but it is not a substitute for them, and it won’t be able to settle the right answers in advance. For now, when we discuss moral uncertainty, we need to wade directly into moral debate, without the aid of decision theory’s formalism.