 A is per se2 with respect to B iff ‘B’ is in the account which gives the essence of A and A belongs to B. Mathematical examples: straight and circular-arc belong to line, odd and even to number. Some commentators have held that it is the disjunction which belongs per se2 (e.g., straight or circular-arc belongs per se2 to all lines); others that the examples are that each predicate belongs per se2 to the subject (e.g., straight belongs per se2 to (some) line). However, Aristotle should know that not all lines are straight or circular.