However, an infinite regress in the completion of causation is of two kinds: the completion of causation in an absolute sense and the completion of a particular causal act. A thing may be a prerequisite for the agent’s being an agent at all, so that he cannot bring about anything except by means of that prerequisite. Such a thing is a condition for causation in the absolute sense—it is a condition for the very genus and root of causal efficacy. Alternatively, it may be a condition for the agent’s producing a specific act. Regress in this second category is not deemed impossible by those who allow an endless chain of effects; for if it is permissible that the agent continuously produce one thing after another, it is likewise permissible that the first act serve as a condition for the second.
As for the first category—an infinite regress in the root of causation—this is impossible, just as an infinite regress in efficient causes is impossible. If a thing could not perform any act whatsoever until it had performed some other act, then the very genus of action would depend on the prior existence of that genus; no act could ever occur unless some act had already occurred. This is impossible in itself, for it entails the existence of a thing before its existence. Existence before existence implies that the same thing is both existent and nonexistent at once—a union of two contradictories.
For this reason, more than one of the leading Muslim scholars have argued that the speech of God is uncreated, citing His words:
“His command, when He wills a thing, is only that He says to it, ‘Be!’—and it is.” (Yā Sīn 36:82)
The verse indicates that He does not create anything until He says to it “Be,” and it is. If the word “Be” itself were created, He would have to create it by means of another “Be,” and that, in turn, would have to be created by yet another command—entailing an infinite regress in the very origin of creation, that is, in causation itself. This is intrinsically impossible, for if nothing were created at all until something else had been created beforehand, the notion would be self-contradictory; and thus