The work of men such as Professor Korr explains in scientific terms what the original precepts of osteopathy mean in practice. How structure and function inter-relate, how the musculo-skeletal system is capable of influencing the well-being of the body as a whole; and the implications of manipulative therapy in restoring normality. Manipulation is the means wherby areas of dysfunction are diagnosed, appraised and treated. Even when such treatment is aimed at relieving symptoms such as a backache or stiff neck, the result will be to normalize the physiological functions by reducing spinal dysfunction. Osteopathic manipulation is, therefore, best seen as a system rather than as a modality. It cannot be understood or assessed adequately outside of the context of the concepts of health and disease, from which it stems, as outlined in this chapter.