A virtuosic case study in psychoanalysis by Sigmund Freud (1856–1939), entitled ‘Psycho-Analytic Notes on an Autobiographical Account of a Case of Paranoia (Dementia Paranoides)’ (1911, Standard Edition, XII, pp. 9–82), based on the memoirs of the German magistrate Daniel Paul Schreber (1842–1911). Freud sought to explain why the particular delusions found in paranoia (now called delusional disorder) are delusions of jealousy, erotomania (1), persecution, and grandeur, rather than any others, and he concluded that the following unconscious homosexual wish-fantasy underlies paranoia in a man: I (a man) love him(a man). Homosexuality being socially taboo, the man with paranoia distorts the wish-fantasy into a more acceptable form. First, he may alter the grammatical subject of the wish-fantasy by projection (1), yielding It is not I, but she (my sexual partner), who loves him, and delusions of jealousy arise. Second, he may alter the object of the sentence by displacement: I don't love a man, because I love women. This is still unacceptable to a Victorian married man, so it is distorted further by projection into Women love me, and delusions of erotomania arise. Third, the verb may be altered by reversal (1): I do not love a man, I hate men, and this may be changed by projection into the more acceptable form Men hate me, yielding delusions of persecution. Finally, he may deny the whole sentence: I don't love a man, because I love no one; but for economic reasons object libido cannot simply disappear but is diverted into ego libido, so this is equivalent to I love no one but myself, yielding delusions of grandeur. If the person with paranoia is female, then the whole chain of argument applies with the gender terms reversed. The reason for the particular group of delusions found in paranoia was thus explained by Freud. See also latent homosexuality, psychoanalytic construction.