 The philosophy of contract includes two broad sets of projects. One set, the focus of the first part of this entry, targets the basic structure and normative justification of the law of contracts. The aim is to subsume a salient body of contract law rules under general principles in order to clarify contract law’s conceptual categories, distinguish it from other areas of law, and specify criteria relevant to its normative appraisal. This kind of philosophical work presupposes detailed knowledge of the law in existing legal regimes, and the entry begins by outlining the common law of contracts.