Stephen Richard Lyster Clark (born 30 October 1945) is an English philosopher and professor emeritus of philosophy at the University of Liverpool.

[3] Clark specialises in the philosophy of religion and animal rights, writing from a philosophical position that might broadly be described as Christian Platonist.

[6] After attending Nottingham High School (1956–1964), Clark won a scholarship to Balliol College, Oxford (1964–1968), graduating with a first-class honours degree in greats (classics) in 1968, followed by a fellowship at All Souls (1968–1975).

[6] Much of the early part of Clark's work was distinguished by writing and service related to animal ethics.

According to a description of the book, "he argues that logical extension of the liberal tradition of sparing animals "unnecessary pain" is sufficient to impose a moral obligation of vegetarianism".