
Derek V. answered 04/02/19
Philosophy Professor with 5 years of Teaching Experience
A few thoughts:
First, there are some philosophers who have argued that some non-human animals are the proper "targets" of our praise and blame, and this is because they think that, whatever it is that makes us the proper targets of praise and blame, some non-human animals have it too.
Second, for those of us who do not think that non-human animals are the proper targets of praise and blame might offer the following reason as to why it is that, e.g. tigers, are not morally responsible for anything they do. The reason is that it's plausible that a necessary, though perhaps not sufficient, condition for some thing to be morally responsible for its actions is that the actions in question are done in light of having a sufficient grasp of the relevant moral facts. This view would have it that if I wrongly take a candy bar from a store and I'm responsible for this wrong, then at the time of taking the candy bar I had a sufficient grasp of the moral facts--i.e. I had a warranted true belief that if I were to take a candy bar in this particular situation, it would be wrong of me to do so. Now, though it's plausible that some non-humans animals are capable of some degree of reason, it's at least doubtful that any non-human animal has or could have a sufficient grasp of any moral fact, and therefore it's at least doubtful than any non-human animal's actions are such that the actions in question are done in light of having a sufficient grasp of the relevant moral facts.
Notice that this view is consistent with non-humans either doing or being able to do wrong actions. Suppose that an alpha-tiger kills every member of his streak. I would say that the alpha-tiger's action is wrong. However, because I don't think the alpha-tiger can act in light of having a sufficient grasp of any moral fact, I don't think the alpha-tiger acted in light of having a sufficient grasp of the relevant moral facts, so I don't think he is morally responsible for the wrong he did.