And if they maintain that from the One, considered under a single aspect, only one being can proceed—and that if two proceed, they must do so from two distinct aspects; or if they insist that this is self-evident and needs no proof, arguing that there must always be a correspondence between the source and what proceeds, and that one aspect cannot correspond to two—then we reply: this assertion undermines your denial of the divine attributes. The Lord has brought forth a multitude of creatures; if from the One, under one aspect, only one could issue, it would be impossible for all these beings to emanate from their Creator in a single way. This clearly shows that He possesses many realities—diverse attributes and diverse actions—by virtue of which all created things have come to be. The very root of their error is their supposition that the universe could issue from the “One” they imagine, a being that exists only in the mind, not in external reality. One scholar spoke well when he said, “A slap in the face is better than the philosophers’ doctrine of oneness”—indeed, even that is an understatement.

If they say, “He is One, devoid of attributes and actions inhering in Him; therefore, were more than one being to proceed from Him, it would mean that from the One, under one aspect, more than one had proceeded,” we answer: if that First Being were one in every respect, then only one being, in every respect, could issue from Him—yet this contradicts plain observation. And if some kind of multiplicity does exist in Him, then more than one has already proceeded from the One under a single aspect. Should they contend that the aspects found in the first emanated being are merely privative, we respond: even so, multiplicity has proceeded from Him by virtue of them. If such a move is allowed, then the many relational properties affirmed of the First may likewise be made the origin of multiplicity. Whichever way their argument is turned, it proves to be more unsound than the Christians’ doctrine of the Trinity.

The essence of their position—as Ibn Sīnā and his followers formulate it—is that any being one might posit in existence would be more perfect than the Lord of all worlds. For they describe Him as “existence conditioned by the negation of every positive reality,” which is what they mean by “existence restricted by the negation of all quiddities” or “existence to which no quiddity attaches.” Ibn Sīnā builds this on his claim that the existence of quiddities is accidental to them, holding that everything contingent in the external world possesses an existence and a quiddity that are distinct.