Abstract

So-called 'hinge propositions', Wittgenstein's version of our basic beliefs, are not propositions at all, but heuristic expressions of our bounds of sense which, as such, cannot meaningfully be said but only show themselves in what we say and do. Yet if our foundational certainty is necessarily an ineffable, enacted certainty, any challenge of it must also be enacted. Philosophical scepticism – being a mere mouthing of doubt – is impotent to unsettle a certainty whose salient conceptual feature is that it is lived. I appeal to psychopathology to show that the lived refutation of a basic certainty is not a manifestation of uncertainty, but of madness.