?

I've argued that our sense of morality springs from the combination of our abilities to empathize and use logic. I see the combination of the two as making up our conscience and the basis for the Golden Rule.

But imagine an intelligent species from another world, a species which didn't have the evolutionary pressure of intricate and subtle social networks, and which leads a far more brutal existence. To this species emotions would be a weakness, and the same goes for empathy. One might well argue that they don't have a moral imperative to treat each other with kindness, that they could harm and kill one another without needing to be judged as evil by outsiders.

But should they be held morally accountable if they murdered a member of an emotional and empathetic species, such as our own?

And should a human be held morally accountable if they murdered a member of the brutish species? Not specifically as an act of revenge (despite the proximity of the questions), but in general?