But over his cell shall be written, with dreadful truth, "He believes in himself." All that concerns us here, however, is to note that this panegoistic extreme of thought exhibits the same paradox as the other extreme of materialism.

It is equally complete in theory and equally crippling in practice.

For the sake of simplicity, it is easier to state the notion by saying that a man can believe that he is always in a dream.

Now, obviously there can be no positive proof given to him that he is not in a dream, for the simple reason that no proof can be offered that might not be offered in a dream.

But if the man began to burn down London and say that his housekeeper would soon call him to breakfast, we should take him and put him with other logicians in a place which has often been alluded to in the course of this chapter.