It is: instead of fighting the bad, grow the good.
Of course, some of the principles we live by become invisible... this is one of those.
It's not my invention. In fact the two wolves the Indian (Native American) tale speaks of, use exactly this principle: feed the good in you.
But the way it was worded in the book I just read was more profound. It says: Let me grow more of the good myself so the bad is less of me.
I didn't need to kill the iceman (in me). I didn't even need to fight him. I just needed to make more of myself, so that he would be less of me.