"Nothing has such power to broaden the mind as the ability to investigate systematically and truly all that comes under thy observation in life. "
"There is but one truly serious philosophical problem and that is suicide. Judging whether life is or is not worth living amounts to answering the fundamental question of philosophy. All the rest — whether or not the world has three dimensions, whether the mind has nine or twelve categories — comes afterwards. These are games; one must first answer."