Doubles everywhere: literary contributions to the study of the bodily self

The topic of the double is a hallmark of romantic, gothic, and fantastic literature. In the guise of the second self, the alter ego or the doppelgänger, fictional doubles have long fascinated critics, clinicians, and scientists. We review classical approaches to the theme and propose a broad clinical and neurocognitive framework from which to examine major instances of the motif in literature. Based on neurological disorders of the bodily self (including unilateral and whole body illusions and duplications), as well as related experimental approaches, we provide examples of literary depictions of bodily fragmentation and splitting; autoscopic hallucinations; the classical doppelgänger, second self, or heautoscopic double; the feeling of a presence; out-of-body experiences; and so-called near-death experiences. Examples include works from Guy de Maupassant, E.T.A. Hoffman, Edgar Allan Poe, Robert Louis Stevenson, Fyodor Dostoevsky, Rudyard Kipling, and others. We discuss these literary cases of doubles from a neurocognitive perspective, and suggest that common mechanisms of the bodily self are involved in the emergence of pathological illusory doubles, literary creations of the double, as well as widespread cultural and religious beliefs about the existence of doubles and the soul.