The hardest question of all to answer is where did our universe come from? If we reply
that it came from somewhere else, brought to its present state by the action of the laws
of physics, we need only add that somewhere else, filled with whatever was in it before it
formed us and our material surroundings, to our present world. We then ask again
where did that new totality come from? Any definite answer to our first question is the
wrong one, since it would lead to an infinite chain of similar questions. We have already
specified that we are talking about everything that is material. There can not be, and
never can have been, anything else, out of which our world came.
