The one book on Philosophy of Law I urge you to buy is A Dictionary of Legal Theory..., a work which you will find accessible and easy to understand ... The great overall contribution by Brian H. Bix, in his books on the philosophy of law, is that he takes concepts that were previously abstract and dry and make them accessible, comprehensible, and interesting! Bix has a talent for making the field of legal philosophy available to the non-expert reader in a thorough, lucid, and engaging way. His genius also is in his ability to take a complex legal problem and go to the jugular instantly, dissecting the problems component parts with surgical skill and providing an excellent analysis and solution and I look forward to the publication of his many other works...