Prominent among the various categories of delusion is the belief that some outside agency is controlling the activities and feelings, and especially the language and thought of the patient. Delusions of control occupy a prominent place in the diagnostic catalogs for schizophrenia, and appear to be the most common form of delusion. The experience that affect, impulses or motor activity are being controlled from outside the body was numbered by Schneider amongst the first-rank symptoms of schizophrenia. Bclass="EmphasisTypeSmallCaps ">leuler regarded schizophrenic delusions, including delusions of control, as secondary to the pathologies of affect, autism, ambivalence and associational disturbance — which he regarded as primary. Nonetheless he did perceive delusions as important components of the schizophrenic syndromes as they are manifested clinically. Freud, of course, regarded the content of all delusions, including delusions of control, as indicative of the motivational conflicts that he believed to be the pathogenesis of psychiatric disorders generally.