Duncan Kennedy's view of Sir William Blackstone's Commentaries on the Laws of England as the first systematic attempt to present a theory of the whole common law system is interesting but wrong. Blackstone himself listed his predecessors, "those who have laboured in reducing our laws to a System": Glanville, Bracton, Britton, the author of Fleta, Fitzherbert, Brook, Lord Bacon, Sir Edward Coke, Dr. Cowell, Sir Henry Finch, Dr. Wood, Sir Matthew Hale. Certainly their arrangements are not free from defects. In particular, as Blackstone pointed out, the arrangement of Fitzherbert and Brook was alphabetical, and Bacon purposely avoided any regular order. But that still leaves the other nine. Kennedy's astonishing error, coupled with his lack of interest in the background to Blackstone, leads him to present an explanation of the structure of the Commentaries in purely ideological terms. But things are not that simple. Legal structures, including the structure of legal treatises, have a strong cultural component which can be uncovered only by historical examination. Much indeed has been written recently on the structure of William Blackstone's Commentaries, most notably by John W. Cairns, who does place the work in its historical context and relates Blackstone's endeavors to those of his forerunners. But even Cairns' account is not complete. The purpose of this Comment is to reveal the true foundations of Blackstone's structure.