أحدها: ما يمتنع وجود أفراده في الخارج، كاللاشيء، واللامكن، واللاموجود
First are concepts whose instances cannot exist externally, such as “non-thing,” “non-possible” and “non-existent” in the text's terminology.
The discussion concerns general headings for which a genuine external instance is impossible. The mind can discuss such a heading; doing so does not bring a corresponding object into existence.
Important distinction: being intelligible as a topic of thought is different from being instantiated in reality. Absence of external referents does not by itself turn every concept into a particular.