[baumbart]

As humans we are evolved to have more compassion the more similar a being is to us, and less compassion the more different it is from ourselves. Human ethics is often selfish (pun not intended) in the sense that it is based on what feels bad for US when doing it. In my opinion, there is nothing objectively "good" or "bad", there is only harmony or disharmony in nature.

Pain indicates critical disharmony with the ideal state of any being. Same applies to plants! Do you think plants feel pain? They certainly do, but "pain" means something entirely different for them. What about planet earth and its ozone levels?

The real question we have to ask ourselves is, how much are we responsible for increasing the harmony in the world around us, vs. focusing on our own expansion in terms of technology, luxury and total population.