if I didn't stand up and at least try to do something, how could I expect anyone else to?

Exactly! Caring for others also involved caring for ourselves through the golden rule and reciprocal cooperation. It's automatically developed as we experience life and see how things work. This is how being "selfish" in Randian terms is accurate. Self-concern is coupled with other-concern in reasonable rationalization throughout life.

Yeah "legal law" is not the same as justice in moral law, as I see it, not sure if that's what you were getting at ;)