Meaning of Yin and Yang

 Yin and Yang means to me that everything is relational.  Nothing is individual or isolated.  Every action takes two or more parties to allow, create, arrange it to happen.  Discrimination doesn't make war.  Discrimination makes discrimination.  War makes war.  War takes two or more parties who are allowing, willing, creating, arranging it.  One hand can't clap; one party can't war.  It takes at least two.  War or peace between my wife and I or between two nations requires both parties making it happen.  The author is correct that neither yin nor yang can exist by itself.  Being aware that an event takes two helps me be more mindful of what I allow, contribute to, and create, and that helps me live more in the way I want to live.     

Agreed!

That is, each of Yin and Yang exist only in relation to the other. There is no "each"! Thisis the case for perhaps everything we can identify: Light and Dark, male and female, balance and imbalance.

The idea of cooperation does not directly shed light on this, but then again,Masahiro Oko's passage refers to an exceptional form of cooperation: effortless cooperation."Cooperation" in the usual sense of the word often implies a struggle or a negotiation and potential failure. But in the Yin & Yang sense, "cooperation" merely appears to exist due to anabsenceof conflict.

There is somethingdeeper to this notion ofeffortless-cooperation, of course:complementarity; peaceful existence (eg a beautiful dance pair performance) as the outcome of complementarity, rather than complementarity as the outcome of a struggle to perform a dance. In human, practical terms, the conclusion appears to be a little harsh: The dance pair who ceaselesslystruggle to achieve should cease and accept that complementarity will find them in some other way.