PHILOSOPHICAL DICTIONARY – Universal

Universal. In the technical language of philosophy, a general notion, that of a class whether genus or species is called an universal.

Since the Isagoge of Porphyry universals have generally been ranged under the five heads of genus, differentia, species, property, and accident, called in the title of his book the five φωναί, but in subsequent times more usually the five predicables. Aristotle, treating of the same subject, recognises only four. The question whether genus and species have independent reality is declined by Porphyry, but became the great philosophical controversy of the Middle Ages, that, under various subordinate aspects, of nominalism and realism.