Makes me think of a hierarchy of alien-ness that Orson Scott Card used in Speaker for the Dead

  “Styrka, Plikt, let me put you another case. Suppose that the piggies, who have learned to speak Stark, and whose languages some humans have also learned, suppose that we learned that they had suddenly, without provocation or explanation, tortured to death the xenologer sent to observe them.”

  Plikt jumped at the question immediately. “How could we know it was without provocation? What seems innocent to us might be unbearable to them.”

  Andrew smiled. “Even so. But the xenologer has done them no harm, has said very little, has cost them nothing-- by any standard we can think of, he is not worthy of painful death. Doesn't the very fact of this incomprehensible murder make the piggies varelse instead of ramen?”
  
  Now it was Styrka who spoke quickly. “Murder is murder. This talk of varelse and ramen is nonsense. If the piggies murder, then they are evil, as the buggers were evil. If the act is evil, then the actor is evil.”

  Andrew nodded. “There is our dilemma. There is the problem. Was the act evil, or was it, somehow, to the piggies' understanding at least, good? Are the piggies ramen or varelse? For the moment, Styrka, hold your tongue. I know all the arguments of your Calvinism, but even John Calvin would call your doctrine stupid.”