The Cognitive Mechanisms of Contractualist Moral Decision-Making

Contractualism is a theory of moral philosophy that posits that an act is morally permissible if all the parties relevantly affected by the act could reasonably agree to it. We take this theory of moral philosophy as an inspiration for a theory of moral cognition. In this paper, we present evidence that subjects have contractualist intuitions and use explicit contractualist reasoning. These data are poorly accounted for by current theories of moral cognition which rely mostly on the use of rules or calculations of consequences. We sketch out a rational model that captures these phenomena by predicting subjects moral judgments as a function of their representation of the interests of agents who are engaged in a mentally simulated bargaining process. We conclude by discussing how a computational cognitive science of contractualism fits into a utility-based unified theory of moral cognition, which integrates elements of rulebased, consequence-based and contract-based cognitive mechanisms.