Social Contract

Hume's sometime-friend Rousseau can be seen as the initiator of a second fundamental question about the contract: that of its scope. Hobbes and Locke had both treated the contract in relation to the justification of political authority, although for Hobbes the contract also turned the precepts of a minimal morality (the "laws of nature") into binding civic law. Rousseau, however, saw the contract as creating simultaneously political legitimacy and genuine moral principles: in transforming asocial or antisocial "men" into civically minded "citizens," his social contract created justice and freedom along with the artifice of political authority. This role of the contract in constructing morality inspired Immanuel Kant (1724–1804), who, in addition to featuring the contract in his political theory, transformed its role in creating moral principles into his idea of the categorical imperative instructing every rational being to act only according to maxims that he or she could will to be a universal law.

Toward the end of the twentieth century, Rawls developed the role of the contract in justifying political authority, while its role in constructing and testing moral principles was developed primarily by David Gauthier, J. C. Harsanyi, and Thomas Scanlon. Scanlon extended a Rawlsian approach from justice to morality, arguing that "contractualism" identifies principles that no one could reasonably reject. By contrast, Gauthier and Harsanyi both bridged the Humean distinction between contract and utility, using contractarian approaches to argue for utilitarian principles as simultaneously morally right and rational to pursue.