experimentation, and commercial hunting. Starting as a leather-wearing, circus-visiting meat eater, a series of musings, experiences, and insights led him to conclude he was morally unable to use animals for meat, clothing, or any other purpose that does not respect their rights. G. E. Moore scholarship In the 1980s, Regan published three books on G. E. Moore's philosophy. The first book, G. E. Moore: The Early Essays, is a collection of essays that were originally published between 1897 and 1903, none of which Moore himself anthologized. Regan argues that these papers reveal Moore' s early taste for speculative metaphysics; in "The Nature of Judgment", for example, Moore maintains that "the world consists of concepts", including existence, "which is itself a concept . . . Thus, all that exists . . . is composed of concepts necessarily related to one another in specific manners, and likewise to the concept of existence." In another paper, "Freedom", Moore enthusiastically affirms his agreement with F. H. Bradley, writing: "I can only say that the arguments by which Mr. Bradley has endeavoured to prove the unreality of Time appear to me perfectly conclusive." Regan' s second book, The Elements of Ethics, is a series of ten lectures Moore delivered in 1898. Large parts of these lectures were carried over by Moore into Principia Ethica and, Regan maintains, these lectures cast important light on Principia' s pages. Regan' s third book, Bloomsbury' s Prophet: G. E. Moore and the Development of His Moral Philosophy, represents Regan' s major contribution to Moorean scholarship. Representative reviews include E. D. Klemke writing that Bloomsbury' s Prophet is "a marvelous book", while Aurum Stroll writes "[t]he portrait of the man Moore that Regan gives us is not only unique . . . but it is well done, indeed." In this book, Regan relies on a trove of unpublished material, housed in the Moore Archive at the University of Cambridge, including Moore' s two dissertations, on Kant' s moral philosophy; correspondence, consisting of letters that Moore wrote as well those he received; scores of papers he read at meetings of the Cambridge Conversazione Society, also known as the Apostles, and at the Sunday Essay Society; and a diary Moore kept throughout his formative years, breaking off on April 19, 1916. Using these materials, Regan argues that Principias primary purpose was (as Moore wrote) to "humble the Science of Ethics" by exposing