You can never solve a problem on the level on which it was created. Insanity: doing the same thing over and over again and expecting different results. A life lived for others is a life worthwhile.
You imagine that I look back on my life's work with calm satisfaction. But from nearby it looks quite different. There is not a single concept of which I am convinced that it will stand firm, and I feel uncertain whether I am in general on the right track.
In one and the same human being there are cognitions that, however utterly dissimilar they are, yet have one and the same object,so that one can only conclude that there are different subjects in one and the same human being.