Rational rules: Towards a theory of moral learning

Moral systems, like normative systems more broadly, involve complex mental representations. Rational Rules offers an account of the acquisition of key aspects of normative systems in terms of general-purpose rational learning procedures. In particular, it offers statistical learning accounts of: (1) how people come to think that a rule is act-based, that is, the rule prohibits producing certain consequences but not allowing such consequences to occur or persist; (2) how people come to expect that a new rule will also be act-based; (3) how people come to believe a principle of liberty, according to which whatever is not expressly prohibited is permitted; and (4) how people come to think that some normative claims hold universally while others hold only relative to some group. This provides an empiricist theory of a key part of moral acquisition, since the learning procedures are domain general. It also entails that crucial parts of our moral system enjoy rational credentials since the learning procedures are forms of rational inference. There is another sense in which rules can be rational-they can be effective for achieving our ends, given our ecological settings. Rational Rules argues that at least some central components of our moral systems are indeed ecologically rational: they are good at helping us attain common goals. In addition, the book argues that a basic form of rule representation brings motivation along automatically. Thus, part of the explanation for why we follow moral rules is that we are built to follow rules quite generally.