, a relation such that when they are bound together in one subject they cancel out their consequences, as in a.a, Realitiesb in appearance (realitas phaenomenon), on the contrary, can certainly be in opposition with each other and, united in the same subject, one can partly or wholly destroy the consequence of the other, like two moving forces in the same straight line that either push or pull a point in opposed directions, or also like an enjoyment that balances the scale against a pain.