This article outlines two models of constructing contract theory: The impinging model (based on metaethical cognitivism), which gives central place to truth and justification; and the projectivist model (based on metaethical non-cognitivism), which gives central place to attitudes and motivation. It is argued that modern contract theories which typically seek to present the whole body of contract doctrine as deducible from, and morally justifiable by, one or a small number of apex principles, presuppose the impinging model. By contrast, a projectivist approach to theory creation does not purport to offer justificatory apex principles, but rather argues for propositions that are likely to have maximum motivational purchase in the practical reasoning of contract law’s subjects. The article then goes on to point out the theoretical cost of the impinging model and argues that projectivist accounts do a better job of accommodating the internal point of view of contract law’s subjects.
