The text’s example: the qualified term “rational”

Semantic Fallacies: Defects of Matter, Form, and Predication

الإنسان ناطق من حيث هو ناطق، ولا شيء من الناطق من حيث هو ناطق بحيوان
The human is rational insofar as rational, and nothing rational considered only in that respect is an animal.

The first statement predicates rationality of humans. The second abstracts “rational insofar as rational,” considering that characteristic without animality as part of its concept. Treating these two standpoints as an identical middle term is the source of the confusion.

Here nāṭiq is the classical logical differentia of the human, not merely the capacity to utter spoken words.