"In reply to your letter of April 22, I think it is meaningless to inquire as to the cause of the world. 'Cause' is, in any case, a concept which belongs to a quite outmoded view. In so far as it is applicable at all, we can speak of one occurrence causing another, but this way of speaking is only applicable to bits of the world. To look for a cause of the whole is like trying to define the spatial position of the universe."