There's a new resource from Italy's Instituto Bruno Leoni: a scholarly web resource on the ideas and work of the great legal scholar for whom the Institute is named, "Rediscovering Bruno Leoni." It has both Italian and English versions and includes mp3 files of some of Leoni’s lectures.
Leoni showed a deep understanding of law and its relationship to voluntary social order. His work on the evolution of law greatly influenced F. A. Hayek and other writers who outlived him. In contrast to prevailing views, he argued that law is not simply an assertion of power, as the legal positivists insist, i.e., a set of "commands of a sovereign," but traces back to the claims made by individuals and adjudicated through a complex process of interaction. As Leoni argued in "Law as Claim of the Individual,"
The legal process always traces back in the end to individual claim. Individuals make the law, insofar as they make successful claims. They not only make previsions and predictions, but try to have these predictions succeed by their own intervention in the process. Judges, juris-consults, and, above all, legislators are just individuals who find themselves in a particular position to influence the whole process through their own intervention.
The cases we bring to court and the cases we don't all are part of the law-making process. The role played by elected legislators is important in the creation of a legal order, but it is almost always overrated. Most of the law that governs our everyday lives resulted from relatively decentralized common law (or Roman law) processes, and not from the "commands" of sovereigns.
Additional resources on Bruno Leoni (and on many hundreds of other deep thinkers) can be found at the extensive and brilliantly organized "Online Library of Liberty."
Other writers with a similar appreciation of law as an evolved body of rules of just conduct include Lon Fuller of Harvard Law School (especially in his classic work The Morality of Law), F. A. Hayek (notably in Law, Legislation, and Liberty, Vol. I: Rules and Order; his classic 1945 American Economic Review essay on "The Use of Knowledge in Society" is must reading for understanding complex social processes, including the evolution of law), and Randy Barnett of Georgetown University, a Cato Institute senior fellow and author of Restoring the Lost Constitution: The Presumption of Liberty and The Structure of Liberty: Justice and the Rule of Law.
So, budding law students and political scientists. Have at it!