REVISED INTRODUCTION TO "PHILOSOPHY OF FREEDOM." The following chapter reproduces, in all essentials, the pages which stood as a sort of "Introduction" in the first edition of this book. Inasmuch as it rather reflects the mood out of which I composed this book twenty-five years ago, than has any direct bearing on its contents, I print it here as an "Appendix." I do not want to omit it altogether, because the suggestion keeps cropping up that I want to suppress some of my earlier writings on account of my later works on spiritual matters. Our age is one which is unwilling to seek truth anywhere but in the depths of human nature. [62] Of the following two well-known paths described by Schiller, it is the second which will to-day be found most useful: Wahrheit suchen wir beide, du aussen im Leben, ich innen In dem Herzen, und so findet sie jeder gewiss. Ist das Auge gesund, so begegnet es aussen dem Schöpfer Ist es das Herz, dann gewiss spiegelt es innen die Welt. [63] A truth which comes to us from without bears ever the stamp of uncertainty. Conviction attaches only to what appears as truth to each of us in our own hearts. Truth alone can give us confidence in developing our powers. He who is tortured by doubts finds his powers lamed. In a world the riddle of which baffles him, he can find no aim for his activity. We no longer want to believe; we want to know. Belief demands the acceptance of truths which we do not wholly comprehend. But the individuality which seeks to experience everything in the depths of its own being, is repelled by what it cannot understand. Only that knowledge will satisfy us which springs from the inner life of the personality, and submits itself to no external norm. Again, we do not want any knowledge which has encased itself once and for all in hide-bound formulas, and which is preserved in Encyclopædias valid for all time. Each of us claims the right to start from the facts that lie nearest to hand, from his own immediate experiences, and thence to ascend to a knowledge of the whole universe. We strive after certainty in knowledge, but each in his own way.