Advocates of animal rights are generally wonderful people. The animal liberation philosophers do a professional job of defending noble ideas. Unfortunately, good intentions are not enough to make a philosophical project successful.

WOULD-BE SHORT-CUTS TO CONCLUDING IN FAVOUR OF ANIMAL RIGHTS

The argument from mentally disadvantaged humans

This argument notes that the main reason why nonhuman animals are given little or no moral status is because they are (allegedly) mentally inferior to normal humans. However, there are humans such as the mentally challenged from birth, those who have had accidents and strokes, and so forth. They also may be so "inferior" (a distasteful term due to its historical connotations). So if these humans have rights, then animals deserve rights too, according to the argument.

However, it is a serious mistake to marshal the argument from mentally disadvantaged humans as a defence of any single theory such as animal rights. This relatively straightforward argument does not hold true no matter what one's theory. The first two prominent ethical theories listed here do permit different treatment of animals and mentally disadvantaged humans, and the second two theories permit like treatment of both types of beings that is far from favorable:

1. Ethical Egoism Since this framework acts for others only insofar as it is in one's self-interest, the view does not favour animal interests if this will not best benefit ego. On this theory, ego can care for his or her family above not only other human families but certainly also nonhuman animals.
2. Moral Skepticism This theory permits any way of life whatsoever.
3. Utilitarianism For instance, utilitarian R. G. Frey supports medical vivisection on both animals and mentally disadvantaged humans, claiming that the benefits from such experiments may well outweigh the costs to the victims.
4. SuperiorismSuperiorists argue that less good is associated with the lives of animals and mentally disadvantaged humans (due to their enjoying fewer kinds of goods, and producing less good in the world), and so therefore it is less worthwhile to assist such beings. Unsurprisingly, Frey adheres to something like superiorism, praising the value of what he calls "richer" lives.

Now let us look at other would-be-short-cut arguments, and the perils of theories that permit the exploitation of animals as those listed above do.

Anti-Speciesism

If any of the theories listed above are right, then falling short of animal rights is not a speciesist outcome but one dictated by legitimate moral theory.

Animals as Persons

Granted, animals have minds and even personalities, but it begs the question to assume that they have moral or legal rights, which is the relevant sense of personhood status for animal rights.

Might Does Not Make Right

This principle plays no part in any of the theories mentioned, except such a principle might be permitted by the nihilism of moral skepticism.

Speciesists Are Selfish

These theories have many adherents who are altruistic, but then, it begs the question merely to assume that ethical egoism is wrong.

We Shoud Not Permit Unnecessary Suffering, Harm, or Violence

Harms to animals and/or mentally disadvantaged humans are permissible on the four theories.

Having Compassion

It can be argued that we should care about others according to the theories in question.

We Should Uphold the Equal Consideration of Interests

This begs the question against ethical egoism, and superiorism, utilitarianism, and moral skepticism allow a like consideration of interests short of animal rights.

It is absurd then to put forward the argument from mentally disadvantaged humans as a defence of animal rights, since someone who adheres to any of the greatest four rivals to animal rights would be totally unmoved by the argument in question. Thus the comparison only preaches to the animal rights choir, who would indeed agree that both mentally disadvantaged humans and animals have strong rights. In sum, ethical egoism and moral skepticism allow treating these two broad types of beings differently, and utilitarianism and superiorism permit treating both categories of animals in like ways that are not favorable to them. This is a total failure since a defence of animal rights must justify animal rights (this argument provides no such justification) and decisively object to theories that compete with animal rights. This much-vaunted argument manifestly fulfills neither goal.

ALTERNATIVE COMPREHENSIVE ANIMAL RIGHTS THEORIES

Tom Regan’s Unreliable Argument for Animal Rights

Regan also uses the would-be-short-cut argument appealing to the case of mentally disadvantaged humans. However, as I have shown, we cannot rely on that argument, so any remaining claim of Regan is intuitionist, such as the intuition that animals have a dignity that must equally be respected. Humanists can simply counter with the intuition that animals do not have such a dignity from the standpoint of ethical theories such as utilitarianism, superiorism, ethical egoism, moral skepticism, and so on. However, here is Regan’s argument which relies heavily on the argument from mentally disadvantaged humans:

1. Mentally disadvantaged humans have a welfare, can be harmed and so intuitively, they have inherent value and we owe them a right to respect and direct duties which should spare them from harm.
2. Mentally disadvantaged humans and nonhuman subjects of a life are relevantly similar in that both can be harmed, have a welfare, and therefore inherent value.
3. Therefore nonhuman subjects of a life also deserve rights.

Regan offers many subsidiary arguments, but it should be noted that he has an intuition that human beings have equal inherent value, which is the key to his overall argument. This argument is helpless in winning over anyone who does not share a similar intuition. For example, someone can intuit that they lack direct obligations to anyone but ego, or that utilitarianism is right, or that nobody has inherent value and therefore moral obligations do not exist in any absolute form. Regan also has other arguments to help his case, such as evidence that many animals have significant mental capabilities, and that we cannot have any decisive evidence concerning souls. He argues that beings can have interests even if they do not use human forms of language. He also objects to theories which compete with his own, although in Universal Animal Rights I illustrate how his objections are inconclusive. At any rate, these other arguments are merely adjuncts to his central argument and while they are noteworthy, they do not vindicate the case for animal rights either.

Gary L. Francione’s Unreliable Arguments for Animal Rights

Francione also relies on the argument from mentally disadvantaged humans (especially in his discussion of medical vivisection which I will not treat here) and intuitionism. His argument can be summarized as follows:

1. Intuitively, human beings have an interest in not being considered property.
2. Intuitively, we should uphold the principle of equal consideration of interests.
3. Intuitively, nonhuman animals have an interest not only in avoiding unnecessary suffering, but also in not being considered property.
4. Therefore, just as humans (we can intuit) have the right not to be considered property, so, due to the equal consideration of interests, do animals also have such a right.

Note that Francione does not use property in the literal sense of ownership, but intuitively associates it with being treated like an object, mere resource, and so on. Like Regan, he addresses other arguments such as “What about plants?” “What about moral dilemmas?” and so forth, but his key argument for animal rights, summarized above, does not work. For like Regan’s case, Francione’s argument does not refute ethical egoism, moral skepticism, utilitarianism, and superiorism. Also, in assuming that we should equally consider and defend everyone's interest in not being considered property, he begs the question or presumes that which needs to be justified in defending his particular version of animal rights. Therefore this is hardly a defence of animal rights and a defeating of anti-animal-rights perspectives, but little more than an intuitionist animal rights declaration in effect.

Francione uses an additional faulty argument:

1. Animals should not be subject to unnecessary suffering.
2. Uses of animals for food, clothing, entertainment, and scientific research all involve unnecessary suffering.
3. Therefore we should not use animals in these ways.

In the spirit of constructive but honest inquiry, I offer much more detailed critiques of Regan’s and Francione’s arguments elsewhere, especially in Universal Animal Rights. (Note that Peter Singer's book, Animal Liberation, which started the modern animal liberation movement but is not so much associated with animal rights but rather utilitarianism, is also heavily dependent on the argument from mentally disadvantaged humans.) The above is only to demonstrate that these other animal rights thinkers by no means provide arguments that win the animal rights debate. If some animal rights activists or academics wish to depend on unreliable research, that is their choice. However, in my considered opinion, it is not credibly in the animals’ best interest to rely upon such arguments.