…and remote consequents.

He said: “As for the second doubt, it too is beside the point, for we do not concede that causality is something other than the very reality of the cause’s essence. Rather, we maintain that to conceive the essence of the cause together with the essence of its immediate effect necessarily yields knowledge that the cause is indeed the cause of that effect.”

I reply: This discourse, which they claim to be a demonstration establishing the universal principles of definition and proof, contains such corruption, error, and contradiction that a full exposition would be lengthy. We shall, however, draw attention to some of it by various routes.

First route: His statement, “The quiddity—by virtue of what it is—necessitates that consequent.” If by this he intends that the quiddity whose consequent is inseparably linked to it is in fact the efficient cause that brings about that consequent, as his words suggest, then this is among the most patent falsehoods. Not everything that is inseparable from something else is therefore its cause that produces it in reality. The cause itself is indeed inseparable from its particular effect: that particular effect exists only by virtue of that cause, and even if something of the same genus were to exist without that cause, it would not be that very individual. Moreover, the cause cannot simultaneously be an effect of its own effect while remaining inseparable from it.

Likewise, one of two effects may accompany the other. Fatherhood and sonship, for example, are concomitant, yet the existence of one is not the cause of the other; rather, both are effects of another cause. The same holds for all concomitants: rationality and the capacity for laughter in the human being are concomitant, with neither being the cause of the other; sensation and voluntary motion likewise accompany one another, yet neither causes the other. Instances of this abound in perceptibles, intelligibles, and matters of revealed law. The stars of the Pleiades, for example, remain together so long as the celestial sphere retains its present configuration, yet none of them is the cause of another. The four humors in the body of the son of Adam are concomitant, and none is the cause of the others. The attributes of the Lord—such as His knowledge and His power—are also concomitant, with neither attribute causing the other. And the proofs indicating—