The expression 'freedom of contract' means a number of different things in different contexts. In American constitutional history, freedom of contract is a constitutional icon of laissez faire having nothing particularly to do with contract. In this context, freedom of contract stands for a substantive due-process right of entrepreneurs to be free of government regulation in all their business activities, contractual and otherwise, or at least free of unreasonable government regulation. It was particularly invoked against government wages and hours regulation (see Currie 1985). In contexts other than the American constitutional one, and particularly in the context of the nineteenth century civil law, freedom of contract was the banner of a theory of contract law, and of private law more generally, that emphasized the free will of individuals and the role of law in facilitating and supporting the freedom of individuals to make whatever social and economic arrangements among themselves they wish to make. In the twentieth century the civil law world, and the common law as well, speaks more of contract than freedom of contact. And contract law is seen not only as facilitative and supportive of freedom of contract but of the regulation of contract behaviour as well (see Eisenberg 1997). In this sense contract law is subtractive from as well as additive to the 'natural' freedom to contract.
Most of this is no doubt better and more completely rehearsed by those who have gone before me, but the regulative aspects of contract law are particularly important when we move to something referred to as the globalization of freedom of contract. So is the distinction between the legal practice of contracting and contract law. I will treat contract law as a form