The use of philosophy is to gather up the whole nature of the world in concepts, abstractly and universally, and thus to store up "a reflected image of it in permanent concepts always at the command of reason." Intuitive knowledge, on the other hand, is expressed most perfectly in deeds and conduct, not in abstract conceptions. To understand it fully, therefore, we must know examples in experience and actual life. A mere description of a beautiful soul is cold and abstract. Schopenhauer refers as models to the biographies of the early Christian and of the Buddhist saints, and in later times to the biography of Spinoza. He holds up with especial admiration the life of St. Francis of Assisi. These records of the lives of simple, self-denying men, mixed as they are with superstition, are for the philosopher far more significant and important than the lives of the great fighters and conquerors of the world. The life of St. Francis is of greater import than that of Alexander the Great. It is the ethical aspect of action which is important, and therefore the most significant life which the world can show is not the conqueror of the world, but he who has in himself subdued the world. It is the quiet, unobserved life of the man who has learned to deny the will to live that is most profoundly instructive.
This ethical teaching is no new thing. It is only the philosophical expression of it which is new. As Christianity developed, the seed of asceticism unfolded into full flower in the writings of the saints and mystics. Even more fully developed and more vividly expressed is this teaching in the ancient Indian writings. In the Indian sacred books, in their poems, myths, and legends, and in the lives of their saints, the love of one's neighbour is taught, and the complete surrender of self enjoined. Such love is not confined to humanity, but includes all living creatures. The path of asceticism is marked as the ideal way for all who strive after true holiness. There is wonderful harmony between the life of a Christian mystic and that of a Hindu saint. In each case the inward life and effort is the same. The rule of life enjoined on both shows striking resemblances. The renunciation of all possessions, the choice of deep, unbroken solitude, which is spent in silent contemplation, perfect chastity, and voluntary penance, is the teaching of Christian and Hindu alike. In such rare similarity of teaching, followed by races differing so radically in outward circumstances, Schopenhauer finds proof that this manifestation has its root in the nature of man, and appeals to an essential side of human, nature.