A persecutory delusion is a type of delusional condition in which the affected person believes that harm is going to occur to oneself by a persecutor, despite a clear lack of evidence. The person may believe that they are being targeted by an individual or a group of people. Persecution delusions are very diverse in terms of content and vary from the possible, although improbable, to the completely bizarre. The delusion can be found in various disorders, being more usual in psychotic disorders.

"On the Origin of the 'Influencing Machine' in Schizophrenia" is an article written by Austrian psychoanalyst Victor Tausk. He read it to and discussed it with the Vienna Psychoanalytic Society in January 1918. It was first published in 1919 in the German-language journal Internationale Zeitschrift für Psychoanalyse and, after translation into English by Dorian Feigenbaum, in The Psychoanalytic Quarterly in 1933.