animal rights *Libertarianism is only advocated for human *persons. Human persons are also animals, of course: a species of primate. “Animal rights” refers to those animals, sometimes known as “beasts”, that are not persons.
A *“right” is normally understood as a *legitimate claim by one person against other people, who thereby have a *“duty” to behave in accord with it. It would be clear to say that someone whose sausages were stolen by another person had thereby had his rights infringed. But if a dog took the sausages it would be odd to say that the dog itself had infringed their owner’s rights (and obviously absurd to “arrest” the dog and put him on “trial”—although such things have been known historically). It would be similarly odd to describe the beating of a dog, however wrong that might be (see *animal welfare), as violating the dog’s rights. The possession of rights implies reciprocal *duties—circumstances permitting, at least—and other animals cannot have literal duties (although a dog might have some inkling of what behaviour is expected of him).
However, it is part of modern *rights inflation that other animals are sometimes held to have rights even though they cannot have duties. Some animal rightists have even called some non-human animals “persons” and asserted that they have *“nations”. This ascription of “animal rights”—and personhood, and nationality—looks to be some combination of *propagandistic hyperbole and a category mistake. One thing that is clearly irrelevant to this debate—and it is, ironically, a form of “speciesism” to assert that it is relevant—is the genetic relatedness, particularly of certain apes, to humans. Being a person is what matters to rights, and that is not necessarily related to a species. If gratuitous cruelty to non-human animals is inherently bad and immoral, this cannot be because those animals have rights.
animal welfare If people object to cruelty to animals, then preventing this is better exemplified by the influence of the *market and *charity than by the *state. People can choose to withdraw their custom from businesses that do not treat animals humanely, or they can buy—or own by first-capture—the animals they wish to protect (including rhinoceroses, elephants, and whales; with GPS tagging and tracking). Animal charities are often more popular than human ones. The state sometimes causes unnecessary animal cruelty, such as the introduction of compulsory animal-testing for various products: this can serve little purpose, especially when human volunteers would otherwise be available and more relevant if allowed.
That said, there is a danger of anthropomorphism and sentimentalism with respect to “beasts” (animals that are not *persons) especially where there is no actual suffering involved, although some experiment might look or sound gruesome. These errors are also muddled with the views of *egalitarian statists who partly use them as pretexts to attack—upper *class—fox-hunting, game-shooting, and fur-wearing but not—lower class—rabbit-hunting, rod-fishing, and leather-wearing. When interest groups can lobby for *legislation on these grounds, then the state can overprotect beasts—or even hurt them—at the expense of people.
A beast has little conception of its own future or its own death, and certainly no life-plan that can be frustrated. Neither has it, in most cases, relations and companions that will grieve severely and long at its death (although these things are sometimes less true of the higher animals, which approach being persons and so might merit more considerate treatment). Many animals only exist, in such great numbers or at all, because we like the products we can obtain from them. And if we continually replace, say, older sheep with younger ones, in a humane way, then there will be more animal *welfare than if we instead allowed the sheep to die of old age or predators; and considerably more animal welfare than if we did not breed them at all (as we largely would not if we could not *exploit them). By contrast, to kill a person is to destroy a higher being with a unique biography and life-plan and mind (intellectual life), and usually a network of similar friends and relations. Any systematic human-killing is also likely to be known about and thus give rise to a general fear and even terror that would undermine human welfare considerably.
People who are sincerely interested in animal welfare should be championing the humane exploitation of animals rather than denigrating all animal use and likening them to persons. Where there is a clash among people in terms of the treatment of animals, both *liberty and humaneness would seem to suggest that it is better to allow the different groups to go their own ways (although *free speech, *boycotting, and purchase remain to persuade the other side) rather than that either side uses systematic *aggressive coercion, paid for by *tax-*extortion if statist, to impose its preferred option on the other.
(These are entries from A LIBERTARIAN DICTIONARY: Explaining a Philosophical Theory [draft currently being revised]. Asterisks indicate other entries.)