You know of the disease in Central Africa called sleeping sickness. . . . There also exists a sleeping sickness of the soul. Its most dangerous aspect is that one is unaware of its coming. That is why you have to be careful. As soon as you notice the slightest sign of indifference, the moment you become aware of the loss of a certain seriousness, of longing, of enthusiasm and zest, take it as a warning. You should realize your soul suffers if you live superficially.
Albert SchweitzerMost men are scantily nourished on a modicum of happiness and a number of empty thoughts which life lays on their plates. They are kept in the road of life through stern necessity by elemental duties which they cannot avoid.
Albert Schweitzer