There are fundamental differences between the standard of probabilities in law upon which a jury must deliberate, andthe standard of certainty in the scientific laboratory of medicine which an investigator must respect. This conflict is nowhere more evident than in the field of psychosomatic disease. This area of medicine has long been recognized but it was only in recent years that it has become the target for intense research. This lack of medical interest in what was considered a fringe area has caused the legal profession to substitute law for medicine. Eventually, however, science will progress in the field of psychosomatic medicine to the point where the lawyer will have accurate, objective tests available toshow causation and to evaluate the extent of damages