The original impulse to write this book came from a course on Jurisprudence which I taught at the University of Virginia Law School in the Fall Semester, 1970.1 should like to thank the members of that class (and of the Comparative Law classes at the University of Edinburgh) for all the stimulus they provided. Abridged versions also provoked valuable comment when presented as lectures at the Law Schools of Louisiana State University and the University of California at Berkeley, and at the Judge Advocate General’s School, Charlottesville. The whole typescript was read and criticised to my great profit by Professors Prodromes Dagtoglou, A. M. Honore and D. Neil MacCormick, Dr. Bernard Rudden and Mr. David Bentley. Other friends, among whom ProfessorJoseph Modrzejewski,Dr.BemardJacksonand Mr. J. L. Barton deserve especial mention, read parts ranging from a single chapter to the greater half.