The world of the happy is quite different from that of the unhappy.

The depressed man lives in a depressed world.

What Copernicus really achieved was not the discovery of a true theory but of a fertile new point of view.

It is a dogma of the Roman Church that the existence of God can be proved by natural reason. Now this dogma would make it impossible for me to be a Roman Catholic. If I thought of God as another being like myself, outside myself, only infinitely more powerful, then I would regard it as my duty to defy him.

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?

Philosophy is like trying to open a safe with a combination lock: each little adjustment of the dials seems to achieve nothing, only when everything is in place does the door open.

The philosopher is not a citizen of any community of ideas, that is what makes him a philosopher.