@trinsec I think I see what you're getting at, but why is the impulse "defend the underdog" rather than "expel the bully?" Particularly, at a certain point bullies are able to achieve tribal dominance.
@dclr42 I'm not really good at explaining it. I think you might find this book worth a read, since it in part also tells about the 'justice' feeling of humans. How we all are, in essence, sort of 'good'.
Humankind: A Hopeful History
by Rutger Bregman
@trinsec Sorry to leave you hanging all weekend. I don't see a strong connection between a naturalistic explanation of the universe and things like justice. It seems like, for these things to exist, there has to be some kind of "higher power."
@dclr42 I'm not talking about the 'justice' that you know from laws. I'm talking about the justitious feeling in every human.
If you see a big bully hurting a smaller person just cause, you feel that this is 'not right'. It's the kind of feeling that makes people root for the underdogs.
Aggressive individuals in any species won't last long in general, because they are putting the whole species in danger. We're not that much different from other species in that regards.