Ideas, such as that of the other world and of different planes, are taught by philosophers in order to give people some notion of the inner world; but in point of fact there is not one inch of space where no beings exist, beings with a form, even if it is a form that our limited sight cannot see. The reason is that the light with which an object, a form, shows itself is dim in these other forms. It is more clear in one way and more dim in another way; it is more clear to our inner perception and it is more dim to our outer sight.