The name under which this notion was to achieve its definitive success already signals the strange ambiguity of its structure quite clearly: on the one hand, it indicates a form of madness none of whose signs appear in the sphere of reason, and in that sense is entirely hidden, a form of madness that makes the absence of all unreason almost invisible, a transparent, colourless form of madness that subtly circulates inside the soul of the madman, interiority inside interiority 'they do not seem mad to superficial observers, and for that reason are all the more harmful and dangerous' but on the other hand, this secret madness only exists on account of its explosive objective existence, demonstrated in violence, wild gestures and occasionally murderous acts.