The upshot of such a statement is to deny His knowledge altogether, for everything that exists outside the mind is a concrete particular. The celestial spheres—each one of them is a distinct particular—and the same holds true for every entity, its attributes, and its actions. One who claims that He knows only universals, therefore, admits that He knows nothing of actual existents; universals subsist only as ideas in minds, not as realities in the external world.

A full treatment of these people is set out elsewhere—most notably in the Refutation of the Contradiction between Reason and Revelation and similar works—for their unbelief is more heinous than that of the Jews and Christians, and even worse than that of the pagan Arabs. All of those groups at least declare that Allah created the heavens and the earth and that He brings creatures into being by His will and power.

Aristotle and the other Greek philosophers worshipped the stars and idols; they knew nothing of angels or prophets, and Aristotle’s writings contain no mention of them. Almost all their learning was confined to the natural sciences.

[The Corruption of Ibn Sīnā’s Patchwork in Theology]

In questions of divinity each of them is seldom correct and frequently mistaken; even the Jews and Christians—despite the alterations that have crept into their scriptures—possess far greater knowledge of such matters than they do. Later figures among them, such as Ibn Sīnā and others, tried to fuse the pronouncements of those earlier philosophers with the revelation brought by the messengers. They borrowed elements from the doctrines of the Jahmites and the Muʿtazilites, cobbling together a school sometimes dubbed “the philosophers of the religious communities,” yet it is riddled with corruption and contradiction that