Résumé
At the turn of the 19th century, French psychiatrists discovered a couple of intriguingly philosophical disorders. Patients suffering from these disorders were characterized as "metaphysician doubters" or "pathological metaphysicians". They relentlessly questioned their existence, the nature of the self, the reality of things around them, or the very identity of their relatives. "When one has seen many of these pathological doubters, Janet lamented, one comes to sadly wonder whether philosophical speculation is a disease of the human mind (Janet, 1909, 302)". Janet was half-joking. Yet, I would like to suggest that he was half-right. More precisely, I argue that the study of such pathological metaphysicians (who are known, today, as patients suffering from depersonalization) can shed some light on a fundamental problem in the phenomenology and epistemology of metaphysics that I dub "the problem of reality", and suggests that the way the philosophical tradition has dealt with this problem is deeply misguided. This problem, which has recently resurfaced in discussions about structuralism, digitalism and virtual realism, stems from the incompatibility of two strong intuitions. According to the first intuition, the deep nature of things is hidden from us, and the world as we know it (through perception and science) is somehow shallow and lacking in reality. For all we know, philosophers have claimed for centuries, we might just be facing shadows in a cave, we might just be dreaming, we might just be brains in a vat, or even sims in a gigantic computer simulation. There is, or there might be, say these philosophers a deeper and so to speak more real layer of reality — ultimate or metaphysical reality — but it is hidden from the delivering of our senses and of our scientific endeavors. This philosophical intuition clashes with an equally strong, but probably more naïve, intuition, to the effect that the world as we know seems perfectly real. A set of shadows, a dream, or an informational structure seems too ethereal, unsubstantial, or virtual (in one word, too unreal) to be identical to the world as we know it. To solve this problem we need to discount one intuition in favor of the other, and metaphysicians have typically discounted the more naïve "intuition of reality". Drawing, on the study of pathological metaphysicians, I will argue that they are wrong.
