They may, for instance, contend that “the One—by unanimous agreement—produces only one effect, because it is simple; were two effects to issue from it, it would be composite. A simple fire, after all, yields nothing but heat; if both heat and cold were imagined to proceed from it, fire would have to be composite.” Now, if this reasoning holds for them in analogical argumentation, it will hold just as well in the universal syllogism; and if it collapses there, it is even more infirm here.

To prove the point by a universal syllogism while dispensing with analogy is impossible. No one can establish a universal proposition by means of a universal syllogism without finding that an analogical proof is easier and more perspicuous; and if he cannot substantiate it by analogy, his inability to do so by a universal syllogism is still greater.

Thus, when they say, “From what is hot nothing proceeds but heat, because it is one, and from the one only one can proceed,” we ask: what do you mean by “proceeds”? Do you mean that the cause produces its effect independently, or merely that it is a contributing cause such that, once joined to something else, the complete agent comes about?

There is nothing in existence that acts alone except God alone.

If you intend the first meaning, we do not grant that anything in the created realm is a fully sufficient agent or that any being acts independently other than God, exalted is He. The hot object that causes heat and the cold object that causes cold operate only upon a substrate capable of being heated or cooled; the heat found in that recipient exists by virtue of both the substrate and the hot agent together. Moreover, the effect is contingent upon the absence of any impediment; should something block the effect, it would not occur. The same applies to the ray of light: if one claims that the sun produces it unaided, the claim is unfounded, for the effect depends on the body upon which the ray is reflected and on the absence of obstacles such as clouds or a roof.

Accordingly, nothing in existence acts by itself save God alone. The Exalted has said: “And of all things We created two counterparts, so that you might take heed” (Q 51:49). Mujāhid and others commented: “That you might reflect and know that the Creator of souls is One.” He, exalted is He, also said: “How could He have a son when He has no consort, and He created all …” (Q 6:101).