determinate instance, and of this determinate instance, and of all other particular instances.” It follows that it is confined within each of its particular instances. Yet its confinement within one precludes its existence in another, just as a particular instance cannot exist within another particular instance. How, then, can it be confined within one particular instance while also being confined within another? This combines contradictory propositions repeatedly—indeed, more times than can be counted.

Had al-Āmidī mentioned this here, he would have recognized the invalidity of this argument, which he formulated on behalf of Ibn Sīnā’s followers in his two major books without explaining its flaw. He would have known how to resolve it, rather than merely offering a counterargument.

Likewise, al-Rāzī frequently argues along these lines, although he also frequently refutes such arguments. As he writes in his Mulakhkhas (Compendium), reporting the position of the proponents of philosophy:

“As for the mental universal, the commonly held view is that it is the mental form—that is, it exists as such only in the mind, not in external reality. In explaining this, they said that what is characterized by universality exists either in the mind or in external reality; otherwise, it would be entirely nonexistent. If that were so, it could not possibly be shared by many. It is impossible for it to exist in external reality, because everything that exists externally is individuated and determinate, and nothing individuated and determinate is shared by many. It follows that nothing existing externally is shared by many, whereas every universal is shared by