The Argument From Marginal Cases For Animal Rights

As of late, I’ve been getting really interested in animal rights philosophy, not because I’m close to turning into a vegan or anything, but simply because I find philosophical arguments that depend on comparative animal psychology to be really interesting. And I’ve been interested in the philosophy of animal minds for a long time, so the connection to my research is obvious. In particular, the Argument from Marginal Cases (AMC) really interests me. The AMC is one of the primary arguments used to support the idea that nonhuman animals have rights just the same as humans.  I found the following summary of the AMC in a paper by Daniel Dombrowski:

1. It is undeniable that [members of ] many species other than our own have ‘interests’ — at least in the minimal sense that they feel and try to avoid pain, and feel and seek various sorts of pleasure and satisfaction.
2. It is equally undeniable that human infants and some of the profoundly retarded have interests in only the sense that members of these other species have them — and not in the sense that normal adult humans have them. That is, human infants and some of the profoundly retarded [i.e. the marginal cases of humanity] lack the normal adult qualities of purposiveness, self-consciousness, memory, imagination, and anticipation to the same extent that [members of ] some other species of animals lack those qualities.
3. Thus, in terms of the morally relevant characteristic of having interests, some humans must be equated with members of other species rather than with normal adult human beings.
4. Yet predominant moral judgments about conduct toward these humans are dramatically different from judgments about conduct toward the comparable animals. It is customary to raise the animals for food, to subject them to lethal scientific experiments, to treat them as chattels, and so forth. It is not customary — indeed it is abhorrent to most people even to consider — the same practices for human infants and the [severely] retarded.
5. But absent a finding of some morally relevant characteristic (other than having interests) that distinguishes these humans and animals, we must conclude that the predominant moral judgments about them are inconsistent. To be consistent, and to that extent rational, we must either treat the humans the same way we now treat the animals, or treat the animals the same way we now treat the humans.
6. And there does not seem to be a morally relevant characteristic that distinguishes all humans from all other animals. Sentience, rationality, personhood, and so forth all fail. The relevant theological doctrines are correctly regarded as unverifiable and hence unacceptable as a basis for a philosophical morality. The assertion that the difference lies in the potential to develop interests analogous to those of normal adult humans is also correctly dismissed. After all, it is easily shown that some humans — whom we nonetheless refuse to treat as animals — lack the relevant potential. In short, the standard candidates for a morally relevant differentiating characteristic can be rejected.
7. The conclusion is, therefore, that we cannot give a reasoned justification for the differences in ordinary conduct toward some humans as against some animals

So here’s why I think the AMC is rather weak.

I don’t have any problems with premise (1). Premise (2) is already problematic though. The claim is that “human infants and some of the profoundly retarded [i.e. the marginal cases of humanity] lack the normal adult qualities of purposiveness, self-consciousness, memory, imagination, and anticipation to the same extent that [members of ] some other species of animals lack those qualities.” While it is undoubtedly clear that a human baby possesses less self-consciousness, imagination, and anticipation that human adults, there is a lot of evidence to support the idea that human babies are remarkably well-developed cognitively, they just lack the capacity of expression. So a human baby is certainly more intelligent than a chicken, and possibly more intelligent than a cow. The problem is that human babies have no way to express their intelligence since they can’t speak yet nor can they use their motor skills to communicate. But subtle experiments demonstrate the extent of their cognitive sophistication.

Moreover, the AMC ignores an obvious extension of the “marginal case” of the human baby: human fetuses. It seems like many speciesist would not include human fetuses in the moral sphere precisely because of how marginal their cognition is. And the development of human-like cognition is one of the markers for where we start drawing the line for abortion. The more developed the brain becomes, the less we feel it’s right to abort a child. And it could be said that the actual birth is an arbitrary cut-off point. If a baby was born without any brain, then it’s likely we would not include that baby into the moral sphere and mercifully end its life without its explicit consent.

But what about mentally retarded people like those with severe autism or Alzheimers? Clearly these entities lack the uniquely human cognitive capacities that characterize a normal human adult, yet we don’t treat them like cattle. Isn’t this inconsistent? Hardly. In the case of most autistic children, I believe the evidence shows that they either have a reduced human cognitive skill set or a different cognitive skill set, but it is rare that they have no skill set at all. I would daresay that your average autistic child is more cognitively sophisticated than a chicken. And the same for your average Alzheimers patient. Likely, an Alzheimer patient, for the majority of their disease progression, has a reduced cognitive skill set, but they don’t lack one altogether. And when such persons do eventually completely lack consciousness, why would a speciesist assume that they have full moral rights? Personally, if I ever developed Alzheimers, I would hope that my society permitted assisted suicide or mercy killing once I reach a totally advanced stage of the disease. Likewise for vegetative coma patients. It seems as if humans who totally lack consciousness are not fully included into the moral sphere, as, say, a normal human adult. This explains our attitudes towards those in comas with no foreseeable chances of recovery.

Thus, I think premise (3) is wrong in almost all cases. Moreover, we can use a different strategy to show why it’s consistent for a speciesist to treat newborn infants differently than they treat cattle: counterfactual biological development. Under normal healthy circumstances, a human infant will grow into a cognitively sophisticated adult. Under healthy circumstances, it is very very unlikely that a cow will grow into a cognitively sophisticated adult. And if that cow ever does mutate and develop the ability to rationally talk and engage humans in high-level moral conversation, then we should include that cow into the moral sphere. But what about someone with severe mental retardation who has no potential to grow into a normal adult? Well, as I said before, it’s doubtful that most retarded children are as cognitively stupid as a cow or chicken. Moreover, we can engage in a counterfactual analysis and think that it would have taken much less different alignment of genes for a retarded child to have been born with the potential to grow into a normal adult than it would be for a chicken or cow. A cow would have to have a total restructuring of the genome in order to produce a brain capable of learning human-like cognitive skills. So the counterfactuals are in fact quite different.

And there is another point where the AMC fails: it paints a false dichotomy whereby either animals have rights equivalent to adult human rights or they have no rights at all. This is a false dichotomy, because we can imagine a continuum of rights rather than an on or off switch. It makes sense to me that although a bonobo or dolphin has less rights than a human adult, it has more rights than a chicken, and a chicken has more rights than an oyster. I would never treat a bonobo like I would a chicken or a mosquito, but I would not treat a bonobo like a human child or a human adult. If there was a burning building, I would rescue a normal human adult or child over a bonobo, but I would rescue a bonobo over a chicken. Moreover, it’s false that this reasoning is arbitrarily speciesist because I would rescue a bonobo over a vegetative coma patient or a human fetus.

Now I want to discuss premise (5): human uniqueness. I see it claimed a lot in animal rights literature that the attempt to find uniquely human cognitive attributes has failed. Oh yeah? What about the set of cognitive attribute that allows you to send a robot to Mars? Or write a philosophy book?* Although there are certainly many similarities between humans and nonhuman animals, I just don’t take seriously anyone who denies the obvious and vast differences. Robot to Mars! Seriously! For those skeptical of human uniqueness, I highly recommend Michael Gazzaniga’s excellent book Human: The Science Behind What Makes Us Unique. As evidenced by practically everything in our culture as well as particular neural structures/functions, we are not just different by degree, but in kind. And even if it was just in degree, the level of difference in degree is of such magnitude it stills warrants the conclusion of human cognitive uniqueness. See this post for more.

So yeah, imo, the AMC has so many problematic premises it can barely even get off the ground as a convincing argument.

*Edit: I’ve realized that someone might wonder why the ability to send a robot to Mars is morally relevant. I don’t think it is. But the type of creature capable of sending a robot to Mars is also probably capable of moral deliberation and reflection, which certainly seems to me like a candidate capacity for bestowing moral worth. But since I do in fact place some value on basic organic sentience, clearly moral reflection is not the source of all of human worth, but I do think it grounds the majority of human worth. In fact, I think moral reflection (which is a skill enables by reflective consciousness) is of such importance than it generates moral value in terms of the counterfactuals for biological potential.


Filed under Consciousness, Philosophy, Psychology

5 responses to “The Argument From Marginal Cases For Animal Rights

  1. Mijnheer

    A few points:

    “Speciesism” is not always defined consistently, but generally it means a type of irrational bias, or prejudice. Someone who claims that, say, all humans have a higher moral standing than all non-humans, would want to show why their position was not speciesist — not why their position was “speciesist” but justified.

    The AMC does not entail that “either animals have rights equivalent to adult human rights or they have no rights at all.” Few people believe that even human children should have all the rights of adult humans; I don’t know of any philosopher who believes that chickens should have the same rights as adult humans. For example, neither Peter Singer nor Tom Regan, each of whom employs the AMC in his own way, believes such a thing. And each of them would favour the typical human over an animal in cases where a choice has to be made. Perhaps you are thinking of the idea that all who count morally deserve to have their interests counted equally with the like interests of others, or equally deserve to be treated with respect. But this does not imply equal treatment or having all the same rights.

    Do you believe that every severely mentally handicapped human being has a mental capacity at least equal to that of a normal bonobo — or dog? If there is one human who doesn’t measure up, but is nonetheless deserving of being treated with respect, then the AMC is still in play.

    Logically, the fact that most humans are moral agents cannot be used to attribute to those who lack moral agency whatever moral worth derives from being a moral agent.

    • Gary Williams

      Hi Mijnheer,

      Thanks for the comment. I understand that “speciesism” is typically used as a derogative term to mean an irrational bias, but I was using the term “speciesist” to mean anyone who thinks that the human species is superior, morally or otherwise, to all other animals. Another term for a speciesist in this sense would be “human chauvinist”. I have no reservations about using the term in this sense to apply to myself, because I actually do believe that humans are superior and unique compared to all other animals. That is, I think humans are on just on an entirely level of cognitive existence than other animals. Of course, I still believe that humans are evolved animals, not divine angels, but for whatever contingent reason not too long ago, humans took off in an orthogonal direction from all other animals, and here we are, talking to each other through an incredibly complex symbolic medium on the internet across vast distances using computers that have been used to explore outer space.

      “I don’t know of any philosopher who believes that chickens should have the same rights as adult humans.”

      I don’t know about philosophers, but from what I understand, animal rights scholar Gary Francione and other “abolitionists” make exactly such a claim and repudiate Singer for not endorsing it. From what I understand, such persons claim that the only morally relevant principle is sentience. Therefore, according to this view, any creature with sentience has just the same right to avoid pain as a human. So I don’t think I am actually attacking a strawman that no one holds. Perhaps there are no major philosophers who defend such a view, but I think it’s highly likely that many hardcore animal rights activists would defend exactly such a view.

      “Do you believe that every severely mentally handicapped human being has a mental capacity at least equal to that of a normal bonobo — or dog? If there is one human who doesn’t measure up, but is nonetheless deserving of being treated with respect, then the AMC is still in play.”

      A few things. No, I don’t believe every severally mentally handicapped person is cognitively equal to a bonobo or dog. But I would only eat a bonobo or dog in an extreme survival situation, not for my nightly dinner. Given their cognitive abilities, I would not treat dogs or bonobos primarily as a means for human food. The same is not true for a chicken or cow. But to my knowledge, bonobos are way more intelligent than a chicken or cow. Similarly, I think it’s wrong to primarily treat dolphins as a source of food. So I would definitely treat a bonobo or dog with “respect”.

      However, according to my proposed principle of genetic counterfactuals for the biological development of human-like cognitive faculties, a bonobo or dog is still “farther away” counterfactually from the human sphere than a mentally retarded person, given that many forms of mental retardation arise from single-point mutations, which is the difference of just one base. Perhaps it is ultimately nonsense to use such intuitive counterfactuals as a ground for morally relevant species differences, but I think it’s at least initially promising as a principle of differentiation. Perhaps it assumes to much about what a “near possible world” is like, but I think the idea is intuitive.

  2. Nightvid Cole

    It seems an obvious empirical fact that people think they have some reason to accept a particular position on a moral issue, when in fact the argument was made up to support the opinion rather than the other way ’round. The influence of family, friends, and culture on one’s moral opinions is, for most people, not only undeniable, but under the right circumstances can overpower any amount of sound argument to the contrary. Consider women’s right to vote for instance. Embedded in a society that values women’s suffrage, almost no one advocates denying it, and yet, one need not look far back in history to see a time when the near-consensus position was that women shouldn’t be granted suffrage because they would just vote the same way as their husbands, a position still held to in some fundamentalist Muslim nations today.

    What this means is for most people, moral reflection is an illusion, and people believe themselves to be thinking for themselves when they are not. I think this makes it absurd to claim that most (over 50%) of our intrinsic moral value is due to moral reflection or reasoning, because, if this were true, most of the population would be excluded. It would be worse to kill one person who does think originally, than two people that don’t.

    • Gary Williams

      Hi Nightvid,

      Thanks for the comment. To clarify, I don’t think our intrinsic moral value results from the *actual* act of reflecting and reasoning about complex moral problems because you are right, most people are not actively reasoning about moral issues in their day to day life. However, the general cognitive skill that enables the possibility of moral reflection also allows us to do other things that are distinctively human. So it doesn’t matter if most people don’t engage in true “moral reasoning”. Their cognitive lives are still of a level of sophistication far above any nonhuman animal. So the cognitive skill that enables moral reflection also enables a cognitive way of life that is, in my opinion, radically different from nonhuman animals. This is particularly evident in our use of complex symbolic technology. So I don’t think my view is committed to the absurd claim that it’s worse to kill one original thinker than two nonoriginal thinkers.

  3. Unexplained


    Thanks for this.

    I find much of the philosophical discussion on this issue seems to be driven by advocacy, so your post is an interesting perspective.

    I also came across this survey / summary (not sure when it was posted):

    I’d be interested in any further response or thoughts you may have.

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