Daniel Paul Schreber’s Memoirs of my Nervous Illness profoundly influenced many key figures of modern psychiatry, including Bleuler and Jaspers, Freud and Jung. Author Elias Canetti described it as the ‘most important document in psychiatric literature’. To read this work – typically considered a paradigmatic expression of paranoid schizophrenia – is to risk a shaking of one’s complacency, especially concerning the key symptom of delusion. For me personally, it was a revelation.

Schreber was an appeals court judge and German citizen who wrote his memoir during an 8-year stay at the Sonnenstein hospital near Dresden. This dense, often convoluted work was published in 1903, together with documents from Schreber’s successful suit for release from involuntary confinement. Against the asylum director’s claim that the patient took his delusions and hallucinations for ‘factual and real’, with ‘unshakeable certainty and [as] adequate motive for action’, Schreber replied with ‘the strongest possible ”no”’: ‘My Kingdom is not of this world’, he wrote; those who think otherwise have ‘not really entered into my inner spiritual life’.

Many of Schreber’s reports are certainly bizarre: a foreign soul ‘joined in looking out of my eyes’; ‘the weather [was] dependent on my actions and thoughts’. He often claimed absolute certitude, and spoke of ‘divine revelation… founded on truth’. Yet it turns out to be difficult to assess the kind or quality of reality that Schreber either experienced or attributed to what he himself termed his ‘so-called delusional system’. How, for example, should we understand his claim that people around him would temporarily exchange heads, or that his own internal organs were ‘torn or vanished repeatedly’, only to reappear ‘without any permanent effect’? Was this simple irrationality and poor ‘reality-testing’, or does it suggest a less literal-minded sort of world – one Schreber himself experienced as being more like a dream than a shared world of real consequences?

Many of Schreber’s (so-called) delusional experiences and claims do not, in fact, suggest the literalness and error so often assumed. He speaks, for example, of seeing ‘rays’ and other delusional entities ‘only with my mind’s eye’. Nor are the experiences well captured by the popular notion of an ‘externalisation’ bias. What Schreber describes often seems, in fact, less an objectifying of something inner or imaginary than a subjectivising, derealising, or internalising of something external and real. Thus, he often experienced the actual people or other creatures in the asylum as unreal: ‘miracled up’ or ‘fleetingly improvised’, and as existing only within range of his own gaze.

It is, perhaps, a certain solipsistic stance that is the most distinctive as well as ‘psychotic’ feature of the Memoirs. Indeed, Schreber sometimes suggests that he himself was the true centre of the world, not only because ‘everything that happens is in reference to me’, but in the deeper, metaphysical sense that things only existed within his own point of view. ‘Seeing’ itself, says Schreber, is ‘confined to my person and immediate surroundings’.

All this is exceptionally hard to sort out in terms of any standard notions of knowledge, belief, and error – Schreber himself speaks of ‘a tangle of contradictions that cannot be unraveled’. The abnormality seems to involve not mere error or cognitive bias, but an entirely different constitution of the world itself. Grasping the possibility of such overall, ontological alterations would seem crucial for any psychotherapist concerned about the patient’s viewpoint; but also for neurobiologists and cognitive scientists: both the experience and underlying ‘mechanisms’ of at least some delusions can, it seems, be vastly different from what we typically imagine. Schreber’s memoir is a book to be sampled, savoured, and pondered, especially for the challenges it poses to standard assumptions, whether from common sense, philosophy, or psychiatric theory.

Daniel Paul Schreber. Memoirs of my Nervous Illness. Transl & ed Ida Macalpine, Richard A. Hunter. Cambridge MA: Harvard University Press, 1988 (Orig: Denkwürdigkeiten eines Nervenkranken. Leipzig 1903). Quotations, listed in the order of appearance, on pp. 320, 301f, 157, 47, 41, 207, 301, 134, 99, 227, 101–107, 197, 232, 152.