This study focuses on a major aspect of literature and culture in the later twentieth century: the intersection of psychiatry, madness and art. As the antipsychiatry movement became an international intervention, W. G. Sebald's fascination with psychopathology rapidly developed. While Sebald collected many materials on Outsider Artists and has several annotated books on psychiatry in his personal library, I examine how Sebald's thought and writings, both academic and literary, were particularly influenced by Ernst Herbeck's poems. Herbeck, a diagnosed schizophrenic, spent decades under the care of Dr. Leo Navratil at the psychiatric institute in Maria Gugging. Sebald became familiar with Herbeck via the book, Schizophrenie und Sprache (1966), in which Navratil analyzed his patients' creative writings in order to illustrate commonalities between pathological artistic productions and canonical German literature, thereby blurring the lines between genius and madness. In 1980, Sebald travelled to Vienna to meet Ernst Herbeck and this experience inspired him to compose two academic essays on Herbeck and the semi-fictionalized account of their encounter in his novel Vertigo (1990).In this study, I reveal how Sebald incorporated Herbeck within his works over a thirty year period in order to provide a social commentary. Sebald looks to Herbeck to examine what had become the standards of normality in Western Germany following the Second World War from a critical perspective. Not only is Sebald's empathetic identification with the outsider Herbeck in itself a political and social act of protest, but I show how Sebald recognized in Herbeck's language an embodiment of his own viewpoints regarding (eco)politics and critical theory. Since his understanding of Herbeck is informed by a number of disciplines, various cultural discourses assist in my clarification: I turn to Sebald's interest in the Frankfurt School thinkers, such as Max Horkheimer and Theodor Adorno; Gilles Deleuze and Félix Guattari's ideas on minor literature; political viewpoints as posed by filmmakers such as Alexander Kluge and Werner Herzog; and also the socio-anthropological writings of Pierre Bertaux, Michel Foucault and Claude Lévi-Strauss. I furthermore provide close readings of Herbeck's poems to argue that Sebald imitates Herbeck's style. Focusing initially on archival material, I locate within Sebald's unpublished poetry and prose several thematic, linguistic and semantic characteristics which are typical of Herbeck's poetry. I then expand this analysis to incorporate how these features also reappear in Sebald's published novels. In uncovering underexplored intertextuality, this study sheds new light both on Sebald's novels, since recognizing Herbeck's voice within his prose calls for a reevaluation of what is "Sebaldian", as well as on the broader, yet underexplored cultural movement from which I focus on Herbeck as the apex. It also locates Sebald's key political ideas and his values concerning poetics and morality as derivatives of a particular historical and psychological discourse.