perceived by the senses. The possibility of such a thing’s existence therefore cannot be established on the basis of the existence of these abstract entities, because this entails circular dependence, with each requiring the prior establishment of the other—which is impossible.

The point is that some of their statements imply that intelligibles comprise only what a person apprehends intellectually within himself, such as universal knowledge. Yet they may claim that these intelligibles exist externally, thereby contradicting themselves. This occurs in the statements of most of them. They all say:

“Universals exist in minds, not in external reality.”

Then some of them say:

“Universals exist externally.”

For this reason, they frequently refute one another on this point. It is one of the foundations of their misguidance and figurative usages.

Their discussion of abstract intelligibles follows the same pattern. They have no proof establishing their existence; when what they offer as proof is carefully examined, it establishes only things apprehended intellectually in the mind.

In their usage, the term (substance) applies to five kinds: intellect, soul, matter, form, and body. They hold two opposing views on whether the Necessary Existent falls within the designation (substance). Aristotle and his followers place Him within the category of substance, whereas Ibn Sīnā and his followers do not. When their assertions concerning intellect, soul, matter, and form are carefully examined, nothing remains in their account except what is apprehended intellectually within the soul, a body, or an accident inhering in a body, as has been explained at length in its proper place.