This text mounts an enquiry into some of the most pressing questions at the start of the 21st century by examining the relationship between biological science and Christianity. The history of biological discovery is explored from the point of view of a philosopher and ethicist. What effect should modern biological theory and practice have on Christian understanding of ethics? How much of that theory and practice should Christians endorse? Can Christians, for example, agree that biological changes are not governed by transcendent values, or that there are no clear or essential boundaries between species? To what extent can nature set our standards? Professor Clark takes a reasoned look at biological theory since Darwin and argues that an orthodox Christian philosophy is better able to accommodate the truth of such theory than is the sort of progressive, meliorist interpretation of Christian doctrine which is usually offered as the properly modern option.