This paper is from the preface to the book, Pastoral Theology, by Hiltner, a professor of pastoral theology. Healing is defined as 'the restoration of functional wholeness that has been impaired as to direction or schedule, or both'. The conditions that make healing necessary result from these types of causal factors: defect, invasion, distortion, and decision. By decision Hiltner does not mean necessarily conscious decision, 'Yet … there is some factor of choice which, however small, in this or that instance, may nevertheless prove prognostically decisive'. Certainly illness is not the result of 'sin' in the primitive sense. Yet to the extent that incorrect decision is a factor in illness 'we must regard sin as crucial in many forms of serious impairment'.