We can infer moral conclusions from nonmoral evidence using a three-step procedure. First, we distinguish the processes generating belief so that their reliability in generating true belief is statistically predictable. Second, we assess the processes’ reliability, perhaps by observing how frequently they generate true nonmoral belief or logically inconsistent beliefs. Third, we adjust our credence in moral propositions in light of the truth ratios of the processes generating beliefs in them. This inferential route involves empirically discovering truths of the form (...) “Process P, which generates belief in moral proposition M, has truth ratio T", and using them to discover probabilities for moral propositions. The inferential route is noncircular, and progress along it is driven fundamentally by induction. (shrink)

Debunking arguments use empirical evidence about our moral beliefs - in particular, about their causal origins, or about how they depend on various causes - in order to reach an epistemic conclusion about the trustworthiness of such beliefs. In this thesis, I investigate the scope and limits of debunking arguments, and their implications for what we should believe about morality. I argue that debunking arguments can in principle work - they are based on plausible epistemic premises, and at least some (...) of them avoid putative problems concerning regress and redundancy. However, I also argue that some debunking arguments fall short because they are insufficiently supported by the empirical evidence. By considering different objections, analyses, and a case study, I explore the conditions for a successful debunking argument. (shrink)

Debunking arguments in ethics contend that our moral beliefs have dubious evolutionary, cultural, or psychological origins—hence concluding that we should doubt such beliefs. Debates about debunking are often couched in coarse-grained terms—about whether our moral beliefs are justified or not, for instance. In this paper, I propose a more detailed Bayesian analysis of debunking arguments, which proceeds in the fine-grained framework of rational confidence. Such analysis promises several payoffs: it highlights how debunking arguments don’t affect all agents, but rather only (...) those agents who updated on their intuitions using a specific range of evidentiary weights; it underscores how the debunkers shouldn’t conclude that we should reduce confidence beyond some threshold, but rather only that we should reduce confidence by some amount; and it proposes a method of integrating different kinds of evidence—about the kinds of epistemic flaws at play, about the different possible origins of our moral beliefs, about the background normative assumptions we’re entitled to make—in order to arrive at a rational moral credence in light of debunking. (shrink)

Animal ethicists have been debating the morality of speciesism for over forty years. Despite rather persuasive arguments against this form of discrimination, many philosophers continue to assign humans a higher moral status than nonhuman animals. The primary source of evidence for this position is our intuition that humans’ interests matter more than the similar interests of other animals. And it must be acknowledged that this intuition is both powerful and widespread. But should we trust it for all that? The present (...) paper defends a negative answer to that question, based on a debunking argument. The intuitive belief that humans matter more than other animals is unjustified because it results from an epistemically defective process. It is largely shaped by tribalism, our tendency to favor ingroup members as opposed to outgroup members. And this influence is distortive for two reasons. First, tribalism evolved for reasons unrelated to moral truths; hence, it would at best produce true moral beliefs accidentally. Second, tribalism generates a vast quantity of false moral beliefs, starting with racist beliefs. Once this intuition is discarded, little evidence remains that speciesism is morally acceptable. (shrink)

A debunking argument contends that some target moral judgments were produced by unreliable processes and concludes that such judgments are unjustified. Debunking arguments face a regress challenge: to show that a process is unreliable at tracking the moral truth, we need to rely on other moral judgments. But we must show that these relied-upon judgments are also reliable, which requires yet a further set of judgments, whose reliability needs to be confirmed too, and so on. Some argue that the debunker (...) faces an insurmountable regress, which disables the debunking conclusion. In this paper, I explore and defuse this regress challenge. (shrink)