Tom Regan (1938–) has based a deontological doctrine of the wrongness of killing innocents, including animals, on the premise that they have intrinsic or inherent worth. It follows from this that humans have an obligation not to harm animals, or at least some of them, for recreation, food, or experimentation. Paul W. Taylor (1923–) has extended Regan’s view in claiming that every living thing, from a germ to an elephant, has a “teleological-center-of-life” that is worthy of moral respect.