“The axiom of the empty set is the axiom of zero. It states that there must be a concept of nothingness, that there must be the concept of zero: zero value, zero items. . . . We can say that life is the axiom of the empty set. It begins in zero and ends in zero. We know that both states exist, but we will not be conscious of either experience: they are states that are necessary parts of life, even as they cannot be experienced as life. We assume the concept of nothingness, but we cannot prove it. But it must exist.”