Which opposition holds between two universal propositions that have the same subject and predicate but differ in quality only?

Two universals with the same subject and predicate differing only in quality stand in contrary opposition.

These are the A and E propositions.

They share quantity, both being universal, but oppose in quality, one affirming and one denying.

Contraries cannot both be true, though both may be false.

This same-quantity, opposite-quality pair of universals is the contrary relation.