The mind-body and man-environment dichotomies are conceptual devices erected to enhance study of man and nature, but linguistics and communication impede attempts to make effective correlations between experience and organic process. Few causal connections have been demonstrated which convincingly link behavior-experience with physiology and pathology. Behavioral scientists have been able to clarify some methodological problems in psychosomatic research, but detailed studies pinpointing the mechanisms mediating psychological event and pathological change are still needed. Differences in the approach of the clinician and the behavioral scientist are discussed. The author feels that many current concepts in psychosomatic medicine are causal hypotheses which primarily fulfil a need of the clinician for causal explanation.