Abstract
Having a body is one of those unquestionable certainties of which we could not really understand the negation: the latter would not be a legitimate doubt in our linguistic, and therefore the epistemic game. In facts, according to Wittgenstein, contravening certain cornerstones of our language game implies that the used combination of words is being excluded from the game, withdrawn from circulation. The idea of this paper is that the external labelling of a behaviour as a mental illness, prima facie, comes from here. Seriously questioning whether someone else controls my actions or my thoughts or whether I am actually dead, then, are not just doubts, as Wittgenstein's critique of G.E. Moore shows: such believes are constitutively excluded from our way of seeing the world and characterized as illnesses, anomalies; otherwise, it would the complete destruction of the language game we inhabit and therefore of the world as we know it, because we would not know on which bases something could be said truthfully or falsely if we did not even know that "this one is my hand". Therefore, even if mental illnesses objectify themselves in correlative physiological dysfunctions, such a discovery comes only after the external recognition of some symptoms, and to recognize the external symptoms of an illness we have to treat them as such; hereby is suggested that we do treat something this way when it threatens the certainties around which the language game we play revolves.