My thesis is the following:
Each thing generates its contrary. That is:
Each thing comes from its contrary.
Some remarks are immediately needed:
1. This law is not, absolutely speaking, universal. -- Laws enjoying exceptions or referring to one part, or to few parts of reality are not less important than the others, and have the further advantage of meaning something.
__Giovanni Papini, L'altra metà (1911), 1: The Law of Contraries