The authors examine the three elements of psychodynamic models that purportedly explain the phenomenon of conversion: defense against anxiety, transmutation of energy, and symbolic expression of conflict. They discuss what they believe to be serious scientific objections to all three. Then having divorced themselves particularly from libido theory, they present their own views: that a patient with a conversion reaction is enacting the role of a person with organic illness, a phenomenon limited to motor and sensory systems. Other contributing factors are the patient's ideas about physical illness, identification with ambivalently regarded objects, and the suitability of symptoms for symbolic representation. [Schilder once expressed his impression that motor and sensory