Nothing that possesses measurable quantity exists in the external world except a body, even though quantity itself can be abstracted in the mind. The highest discipline, according to them, is what they call “metaphysics” when considered as a study of actual existence; they also dub it “divine science,” “first philosophy,” and “supreme wisdom.” By this they mean that which is abstracted from matter both in thought and in external reality.

When a specialist who understands realities examines their discourse on these sciences, he finds that they possess no knowledge of anything that actually exists outside the mind except for the branch they call “natural science” and—for the most part—the mathematics that is directly attached to it. As for mathematics considered as a pure mental abstraction, it is merely a set of judgments concerning mental magnitudes that have no existence in the external world. Likewise, the discipline they have named “metaphysics”—which they have stripped of matter both mentally and externally—yields, upon reflection, no knowledge of any being that exists in reality; they have simply imagined hypothetical notions that enjoy no external existence. Hence the furthest reach of their investigation, the endpoint of their philosophy and wisdom, is nothing but “unqualified, universal existence,” or an existence defined purely by the negation of every positive predicate.

Thus the subject of their so-called “divine science,” which investigates being and its concomitants, is the universal concept of existence divided into substance and accident, cause and effect, eternal and contingent. This has no reality outside the mind; it is a mere mental construct—yet it is what they regard as the highest science. In truth, the Most High who exists externally is Allah—there is no deity but He—who revealed:

“Glorify the Name of your Lord, the Most High, who created and proportioned, who measured and guided, who brought forth the pasture and then turned it into dark stubble.” (Q 87:1–5)

As for the Necessary Existent that they affirm, they either conceive it as a being stripped of every positive and negative determination, or they claim—as does Ibn Sīnā and those like him—that it is qualified solely by negations, devoid of any affirmative attributes. Such a notion exists only in the mind, not in external reality, for it is impossible for something real to be bereft of every positive quality—or of both positive and negative qualities altogether. Indeed, any insignificant existent you might posit would be better than this entity that is described by no positive attribute, for it shares with that lowly thing only the name “existence,” differing from it merely by a privative description.