Includes bibliographical references and index.

"Formidable barriers stand in the way of developing a unifying theory of contracts. When disputes arise, contract terms may fail to provide an unambiguous basis for determining obligations; indeterminate terms, unexpressed but implied obligations, and unaddressed ex post circumstances all require a basis from which we can use the raw material of the exchange, its text and context, to determine each party's obligations. The variety of subject matter, promissory utterances, and relationships based on promising and contracting add layers of complexity to any effort to find a single method for deciphering obligations. We might wonder whether we should ever hope to develop a unified mental map for evaluating promissory relationships as different, for example, as intimate social relationships and detailed provisions for maximizing cooperation over time. The variety is capacious enough to house many kinds of theories, but the realm is diverse enough to suggest the impossibility of a general, coherent theory of contracting and promissory obligations"--