The psychodynamic explanations for the Capgras delusion are reviewed. A critique is offered, showing how these theories fail to account for several important clinical phenomena found in patients with the Capgras delusion. A new psychodynamic theory is suggested that attempts to encompass all of the significant clinical phenomena. This hypothesis is based on findings in a series of fourteen schizophrenic patients with the typical delusion. The focus is on the patient's loss of a stable sense of identity. By the process of projection the patient ascribes his identity diffusion to those around him who are then seen as unreal impostors.