Stephen Richard Lyster Clark (born 30 October 1945) is a British philosopher and professor emeritus of philosophy at the University of Liverpool.Clark specialises in the philosophy of religion and animal rights, writing from a philosophical position that might broadly be described as Christian Platonist. He is the author of 17 books, including The Moral Status of Animals (1977), The Nature of the Beast (1982), Animals and Their Moral Standing (1997), G.K.