From the chapter on Soul and God (emphasis added by me):
“I must learn that the dregs of my thought, my dreams, are the speech of my soul. I must carry them in my heart, and go back and forth over them in my mind, like the words of the person dearest to me. Dreams are the guiding words of the soul. Why should I henceforth not love my dreams and not make their riddling images into objects of my daily consideration? You think that the dream is foolish and ungainly. What is beautiful? What is ungainly? What is clever? What is foolish? The spirit of this time is your measure, but the spirit of the depths surpasses it at both ends. Only the spirit of this time knows the difference between large and small. But this difference is invalid, like the spirit which recognizes it.
The spirit of the depths even taught me to consider my action and my decision as dependent on dreams. Dreams pave the way for life, and they determine you without you understanding their language. One would like to learn this language, but who can teach and learn it? Scholarliness alone is not enough; there is a knowledge of the heart that gives deeper insight. The knowledge of the heart is in no book and is not to be found in the mouth of any teacher, but grows out of you like the green seed from the dark earth. Scholarliness belongs to the spirit of this time, but this spirit in no way grasps the dream, since the soul is everywhere that scholarly knowledge is not.
But how can I attain knowledge of the heart? You can attain this knowledge only by living your life to the full. You live your life fully if you also live what you have never yet lived, but have left for others to live or to think. You will say: “But I cannot live or think everything that others live or think.” But you should say: “The life that I could still live, I should live, and the thoughts that I could still think, I should think.” It appears as though you want to flee from yourself so as not to have to live what remains unlived until now. But you cannot flee from yourself. It is with you all the time and demands fulfillment. If you pretend to be blind and dumb to this demand, you feign being blind and deaf to yourself. This way you will never reach the knowledge of the heart.
The knowledge of your heart is how your heart is.
From a cunning heart you will know cunning.
From a good heart you will know goodness.