Such was the ambiguous role of sceptical thought, or rather of a form of reason that was vividly conscious of the forms that limited it and the forces that contradicted it: it discovered madness as one of its own figures one way of warding off anything that may have formed an exterior power, irreducible hostility or a sign of transcendence; while by the same token placing madness at the heart of its work and indicating it to be an essential moment in its own nature.