Madness has always stalked the world of philosophy. David Hume and John Stuart Mill suffered nervous breakdowns in their youth. Friedrich Neitzsche experienced a mental collapse â often attributed, with little historical evidence, to the sight of a horse being flogged. A similar legend follows the German mathematician George Cantor who supposedly went mad contemplating infinity. Beyond full-blown psychosis, there is âa more common occurrence,â says Wouter Kusters. âA certain kind of consistent philosophising may very well result in confusion, paradoxes, unworldy insights, and circular frozenness that is reminiscent of madness â which in fact is what happened to quite a few philosophers who are far from unimportant.â