We land in the same dilemma if we pursue another road. Philosophers of certain schools place existence in two categories. There is the world of appearance (phenomena), and there is the world of reality or substance (noumena). We know phenomena and their laws, they say, but no more. We do not know, and cannot know, Substance in itself; and the theist promptly adds that this unknown substance is but another name for God. The philosopher also warns us against applying the laws of the phenomenal world to noumena, reminding us that what we call "laws of nature" have been devised to explain the world as it presents itself to our consciousness. And to this we have the theological analogue in the warning not to measure the infinite by the finite or to judge God by human standards. Now granting all this, let us see how the argument stands. The laws of phenomena belong exclusively to the phenomenal world. Their application and their validity are restricted to the world of phenomena. When we leave this region we are in a sphere to which they are quite inapplicable. What, then, can be meant by speaking of God as a "First Cause"? Cause is a phenomenal term, it expresses the relations between phenomena, and it has no meaning when applied to this assumed and unknown reality. We are in the position of one who is trying to use a colour scale in a world where vision does not exist. The theist is trying, in a similar way, to use the conception of "cause," which is created to express the relations between phenomena, in a world where phenomena have no existence. Thus, when the theist, to use his own words, has traced back an effect to a cause, and this to a prior cause, and so on, till he has reached a "First Cause," what happens? Simply this. At the end of the chain of phenomena the theist makes a mighty jump and gains the noumenon. But between this and the phenomenon he can establish no relation whatever. It cannot be a cause of phenomena because on his own showing causation is a phenomenal thing. He has worked back along the chain of causation, discarding link after link on his journey. Finally, he reaches God and discards the lot. And here he is left clinging with _no intelligible way of getting back again_. If on the other hand, he relates God to phenomena he has failed to get what he requires. He has merely added one more link to his chain of phenomena, and the "first cause" remains as far off as ever. For if God is not related to phenomena he ceases to be a cause of phenomena in the only sense in which he is of use to the theistic hypothesis.