Theresa Lopez

In our everyday moral deliberations, we attend to two central types of considerations – outcomes and moral rules. How these considerations interrelate is central to the long-standing debate between deontologists and utilitarians. Is the weight we attach to moral rules reducible to their conduciveness to good outcomes (as many utilitarians claim)? Or do we take moral rules to be absolute constraints on action that normatively trump outcomes (as many deontologists claim)? Arguments over these issues characteristically appeal to commonsense intuitions about various cases. As a result, an important portion of the debate involves empirically tractable questions — questions that can be investigated by probing for people’s judgments in cases in which the two types of considerations come into conflict with one another.

People draw subtle distinctions in the normative domain. But it remains unclear exactly what gives rise to such distinctions. On one prominent approach, emotion systems trigger non-utilitarian judgments. The main alternative, inspired by Chomskyan linguistics, suggests that moral distinctions derive from an innate moral grammar. In this article, we draw on Bayesian learning theory to develop a rational learning account. We argue that the ‘size principle’, which is implicated in word learning, can also explain how children would use scant and equivocal evidence to interpret candidate rules as applying more narrowly than utilitarian rules.