A surprisingly common argument against animal rights goes like this: only beings capable of exercising moral choice and reasoning have rights. Animals don’t exercise moral choice and reasoning (i.e. they aren’t “moral agents”). Therefore animals don’t have rights.

I say that the frequency with which this argument is made is surprising because it implicitly denies something that most of us, I think, believe, namely that there are certain human beings who have moral rights who aren’t necessarily moral agents. Infants, children, the severely mentally handicapped, the brain damaged and comatose, and people with severe Alzheimer’s are, almost certainly in some cases and quite probably in others, incapable of moral reasoning and choice, and yet no one (or hardly anyone) is willing to bite the bullet and say that these classes of human beings have no moral rights. In fact, I suspect that most of us would find the denial of moral rights to any or all of these classes of people to be morally monstrous.

So, it’s hard to see why being a moral agent should be taken to be a necessary condition for being a moral patient, or an object of moral concern. No one proposes that we can treat, say, an infant any way we wish simply because he or she isn’t capable of moral reasoning and choice. It may be that being a moral agent is a sufficient condition for being a moral patient, but I’m hard pressed to see any reason why it should be necessary.

I wonder if the roots of this argument lie in a kind of “contractualist” way of thinking about morality. That is, morality is seen as a kind of contract or bargain into which people enter in order to establish mutually beneficial rules of conduct. If that’s what morality was, then you could see the plausibility of holding that only moral agents had moral rights, since they’d be the only ones capable of entering into such a contract.

But it’s pretty clear that’s not what morality is like, at least if we don’t want to abandon deeply held beliefs about the duties owed to infants, children, the mentally handicapped, etc. Contractualism has a very hard time making sense of moral duties that go beyond what self-interested rational agents have, or would agree to.

A better criterion of who counts morally, far more plausible than the capacity for moral agency, is the capacity for experience. That is, the possibility that one’s life can go better or worse for oneself. Rocks don’t count morally because things can’t go better or worse for a rock. But things can certainly go better or worse for a chimpanzee, a pig, a chicken, a trout, and quite possibly a grasshopper. There’s no particular reason why the pain of an adult human being considered simply in itself should count for more than the the pain of an infant, or an animal, other things being equal. And there’s certainly no good reason why the fact that a being lacks the capacity for moral reasoning should entail that we can treat it in any way whatsoever, that anything goes.

It doesn’t follow from this that animals would have all the same rights as human beings (a right to education, say, or health care, or subsidized museums). This is because, as philosopher Mark Rowlands has pointed out, they have no interests in such things. But they do have interests in things like not suffering, not being killed, and so on, and it’s not at all clear why those interests should be utterly disregarded for the mere convenience of human beings, as they often are.