Quote from : Desert Solitaire Book

Has joy any survival value in the operations of evolution? I suspect that it does; I suspect that the morose and fearful are doomed to quick extinction. Where there is no joy there can be no courage; and without courage all other virtues are useless. Therefore the frogs, the toads, keep on singing even though we know, if they don't, that the sound of their uproar must surely be luring all the snakes and ringtail cats and kit foxes and coyotes and great horned owls toward the scene of their happiness.