What is happening to contract law teaching? For years students and teachers alike have relied on weighty tomes in the “treatise” mould—books which attempt to reconcile the irreconcilable and which acknowledge conflicts only as a synonym for private international law. For those willing to countenance a casebook, only the comprehensive, albeit conservative, collection compiled by Professor J. C. Smith and the late Professor J. A. C. Thomas has merited any serious consideration. The underlying message of these traditional works is that the law of contract is defined by a set of unified principles derived from the twin concepts of voluntary agreement and reciprocal promise. According to this approach, doctrines that purport to resolve problems caused by asymmetrical information, changing market circumstances, or the occurrence of unforeseen contingencies are rationalized by a clear conception of what does and what does not constitute legal agreement and by clarification of the notion