John Chipman Gray 
Nature and Sources of the Law by John Chipman Gray [PDF ebook] 

First published in 1909 and then again in 1997. John Chipman Gray (1839-1915) spent the greater part of his professional life as a professor at Harvard Law School where he taught property, trusts and future interests. The Nature and Sources of the Law was first published in 1909. The book is divided into two parts which respectively look at ‘Nature’ and ‘Sources’. In Part I, Gray warns that the study of jurisprudence, in isolation, could lead to dogmatism. Rather he advocates the structure offered by common law with its reliance on flexible interpretations of statutes, the use of all relevant cultural inputs and a highly adaptable approach to the resolution of disputes. Gray, in Part II, turns his attention to sources of the law and begins with statutes. Here he asserts that judges are the ones who actually turn into law, going against the conventional scholarship that judges merely interprets statutes. He also extensively examines the influence of tradition and the common law.