Abstract
This article examines a particular facet of the new and old institutionalists, i.e., the similarities and differences between Hayek and Commons on legal rules. It is not clear, however, that sufficient uniformity exists between Hayek and other new institutionalists, to warrant any meaningful generalizations. These differences stem primarily from their alternative conceptions of the evolutionary process. We find Hayek interpreting in a manner that restricts the interventionist role of government whereas Commons argues for a more activist stance.