In his most substantial work since the famous Principles of Christian Theology, John Macquarrie has turned to the study of human nature. As he rightly points out, one learns about humanity chiefly from meeting human beings and living in the human condition, but to explore its full dimensions help can be found from other sources. Those drawn on here are on the one hand, Christian theology, and on the other, a variety of philosophies, mainly continental, which from Kant to the present day have reflected on human nature and human destiny. While working mainly this tradition, Professor Macquarrie has also drawn on the researches of biologists, psychologists and others.