Brian Tamanaha comments on the latest Lexicon entry over at Balkinization. His thoughtful reaction prompted the following addition to my post:
In some ways, the title of this Lexicon entry is misleading, because of our focus on the "What is law?" question as it has been approached by contemporary legal philosophers. There are other important perspectives on the nature of law that focus on law’s functions rather than the the meaning of the concept or the criteria of legal validity. For example, the sociological tradition includes important work on the nature of law by Max Weber and Niklas Luhmann. These issues are discussed by Brian Tamanaha in the article cited in the Links section at the end of this entry.
His piece can be found here.