Paths to Knowledge of Higher Worlds

What is it that gives us the right to speak of reality in the physical world? Several things may be taken into consideration. I should have to speak for hours from the standpoint of a theory of knowledge (of course, I cannot do this now) in order to prove the fact which I now briefly wish to summarize. But if you follow the corresponding train of thought you will see that the following fact can be accepted: In the physical world we designate a fact as “real” when it influences us in such a way that we should be obliged to deny our own existence were we to deny the existence of that thing. If you not only hear the sound of a bell, but if you can touch it and discover its connection with other things, you would have to blot out your own self if you were not able to say that the external object is real, when you experience its reality within your soul. An external object can be called real, if we should have to deny our own reality in denying the reality of the object.