Lost Son

Letters to His Son
But here is where our second fact begins, which has much, much more weight than the first. For your own alive-ness, your being a human, your experience exists only in your thinking. You stand there, singularly alone with your thinking in the midpoint of your experience, and if you now look at yourself, so to speak from the inside out, no longer are you a human being in the usual sense of the word, that is, mortal per se; you are simply a thinking “I” and nothing else. This fact is of course a much firmer, solider fact than that of death, because all the dying that you see around you is merely the content of your thinking.
But now we come to the crux of the matter: for the “I,” life would be just a dream, and would be like a dream, as you correctly say, pointless and valueless, if there were no “eternal truths,” no “eternal values,” or as philosophy terms it, nothing “absolute.” Since your “I” is totally alone, however, it has to create all these beautiful things for itself: and in fact the human spirit has done exactly that. For all the truth one can experience, all the beauty, every value, in short, all “reality,” has been created by the mind itself. It's reality that the stars move in elliptical paths, but to find them, or rather, to invent them, required the mind of Kepler. Even just to recognize the beauty of nature, let alone imitate it, required thousands of years of intellectual effort.
So it is the task of the “I,” insofar as it yearns for absolute truth and absolute value (out of this fear of death), to constantly create anew its own reality, and to constantly expand it. The human mind of course will never grasp the final truth about the world and life, for “to know all would mean to be God.” But what makes all value-creating work rewarding is that it allows us, makes it possible in the first place for us to approach this ultimate goal. Even learning in itself is a part of this reward, because it keeps enlarging the breadth of reality available to the learning “I”; and if it is ever your fate to accomplish productive, value-creating work of your own, in the artistic, scientific, or whatever other field it may be, then you will experience a joy, a joyousness that will make it clear to you that the idea of death, even more than that, death itself can at least partially if not wholly be overcome. The founders of the great religions were not idiots in preaching the doctrine of eternal life: as philosophers, they created their own personal immortality from within themselves. Granted, this doesn't mean that they are flitting around heaven as little angels with harps or pianos, or that they are wandering about the earth as spirits whom we can lure into saying “hello” to us at spiritualist séances, but that the individual human being, the single “I” looking out from within himself, can overcome death.