As for the other dictum, that God is "living but not with life," "powerful but not with power," "knowing but not with knowledge," and so on; what do they mean by this circumlocution? If they say "living" to indicate that he is not dead, and add "but not with life," so as to prevent a comparison of him with other living things, why not say also, "He is body, but not like other bodies"? If the objection to calling him body is that body is composite, and what is composite must have been composed by someone and is not eternal, the same objection applies to "living." For "living" implies "breathing" and "possessed of sensation," hence also composite and created. If they reply, we mean life peculiar to him, we say why not also body peculiar to him? You see these people entangle themselves in their own sophisms, because they do not know what demonstration means.[174] Having disposed of the errors of the Mutakallimun, we must now present our own method of investigation into the nature of God. To know a thing, we investigate its four causes--material, formal, efficient and final. What has no cause but is the cause of all things, cannot be known in this way. Still it is not altogether unknowable for this reason. Its essence cannot be known, but it may be known through its activities, or rather effects, which suggest attributes. We cannot therefore know concerning God _what_ he is, nor _how_ he is, nor _on account of what_, nor _of what kind_, nor _where_, nor _when_. For these can apply only to a created thing having a cause. But we can ask concerning him, _whether_ he is; and this can best be known from his deeds. We observe the things of the world and find that they are all composed of substance and accident, as we saw before (p. 131). These are correlative, and one cannot exist without the other. Hence neither precedes the other. But accident is "new" (_i. e._, not eternal), hence so is substance. That accident is new is proved from the fact that rest succeeds motion and motion succeeds rest, hence accidents constantly come and go and are newly created. Now if substance and accident are both new there must be something that brought them into being unless they bring themselves into being. But the latter is impossible, for the agent must either exist when it brings itself into being, or not. If it exists it is already there; if it does not exist, it is nothing, and nothing cannot do anything. Hence there must be a being that brought the world into existence. This is God.