Traditional Eastern philosophies view mind and body as different manifestations of the same life force. In the West, one of the earliest medical theories held that disease is a result of an imbalance of nonphysical humours. The ancient Greek physician Hippocrates, originator of the Hippocratic oath, taught that the body has its own inner healing power, called physis.
Plato, the Greek philosopher, was the first to make a sharp distinction between mind and body. He believed that the mind could exist before and after, as well as during, its existence in the body. In the 17th century, Western philosophers, particularly Rene Descartes, put forth a clear distinction between mind and body, a position known as dualism. Dualism became the paradigm for modern medicine and still dominates medical thinking.
At the end of the 19th century, Sigmund Freud, one of the founders of modern psychiatry, demonstrated that physical symptoms such as blindness or paralysis, may develop in response to prolonged emotional conflict. His famous pupil Carl Jung, believed that people's emotions and thoughts are intimately connected to the basic life energies in their bodies.
Psychosomatic medicine arose in the '40s as an outgrowth of Freudian psychiatric theories. Psychosomatics claimed that periodically recurring emotional states caused physical injury to organs, altering an individual's susceptibility to disease.
This was succeeded by behavioural medicine. Patients were perceived less as walking diseases and more as people with physical ailments who exist in a social context. Behavioural medicine tended to explain the effects of emotions on the body through physiological mechanisms.
In the '70s, the concepts of psychosomatic medicine and behavioural medicine were synthesised to produce holistic medicine. This emphasises the unity of the human organism -- integrating the physical with the intellectual, emotional and the spiritual -- when dealing with disease.