Porter was in a thoughtful mood the other  night

 and wrote a poem he called 

yin yang:

A sign of peace?

A sign of love?

The white a fluttering dove?

But what is the black?

The side that attacks?

What about the opposite color in each?

Is it just like the words of the preach

There is good in all evil.

There is evil in all good.

(All of this is under my hood.)