Not only is there no guarantee of the temporal immortality of the human soul, that is to say of its eternal survival after death; but, in any case, this assumption completely fails to accomplish the purpose for which it has always been intended. Or is some riddle solved by my surviving forever? Is not this eternal life itself as much of a riddle as our present life?

The eternal life is given to those who live in the present.

One can mistrust one's own senses, but not one's own belief.

He who lives in the present lives in eternity.

Language disguises thought.

Always get rid of theory private object in this way: assume that it constantly changes, but that you do not notice the change because your memory constantly deceives you.

A tautology's truth is certain, a proposition's possible, a contradiction's impossible.