The Catholic Church's traditional teaching on the nature of man comes under heavy fire today when it finds itself increasingly in conflict with the standards of a society that has largely abandoned the concepts of both natural law and a positive law sanctioned by God in favour of an ethical code that is based on materialism and governed by expediency. Criticism and hostility are especially fierce when the conflict centres on modern medical science and its methods. In this book, Dr. John Marshall discusses the difficulties faced by Catholic doctors and their patients. A discussion of the nature of man and the body-soul relationship is followed by an outline of the determining factors in the practice of medicine and the effect upon them of obedience to the natural and divine laws. A chapter devoted to the Catholic doctor's place in the Mystical Body of Christ is followed by detailed consideration of major problems such as contraception, therapeutic abortion, eugenic sterilization, pre-frontal leucotomy, the relief of pain, "mercy killing" and the much misunderstood "mother or child" problem. Concluding chapters discuss the preservation of life and the issues raised by the teaching of Freud and modern psychiatry in the treatment of Catholics.