1. Based on random choice or personal whim, rather than any reason or system.
2. (of power or a ruling body) Unrestrained and autocratic in the use of authority.
All animals are heterotrophs, meaning that we must eat other things in order to survive. Most often, those things we eat are (or were) other living things. How should we human animals, as rational moral agents, decide which of the living things we ought to eat?
We could make a arbitrary decision. For example, we could, as human beings, decide without any real and independent reason, that only birds are fit to eat, or that only dogs are. We could decide that only cows raised on small farms where they get to live in rolling pastures are fit to eat, or only the eggs of chickens who are kept in large enough cages are. There are all kinds of arbitrary decisions we could make about what we consider fit for human consumption. Every other living creature, in some culture or another, at one time or another, is fair game for our gustatory bill of fare. Every animal – other than the human one – is on the menu for some diner somewhere and that’s arbitrary.
But wait, it will be said, it’s not an arbitrary choice to eat other animals but not humans. It’s a reasonable choice that can easily be defended. No, it is not. There is no relevant difference between the human and other animals. Choosing to not eat humans just because they happen to be human is arbitrary, just as it would be arbitrary to choose to not eat dogs just because they happen to be dogs – as opposed to cows. Or to not eat parakeets just because they happen to be parakeets - as opposed to chickens. Or to not eat cats just because they happen to be cats – as opposed to pigs.
The reason most Westerners do eat pigs, but not cats, has nothing to do with any relevant difference between pigs and cats. There’s nothing special about pigs – as pigs – which makes them somehow demonstrably different as sources of protein. There’s nothing special about cats which makes them completely unsuitable as sources of sausages. Other cultures do eat cats. And cockroaches, and leeches and the brains of monkeys. Those who eat pigs eat them just because they eat them. There is no relevant difference between pigs and cats when it comes to eating one and not the other. We eat pigs largely as an arbitrary matter of acquired taste (and because a huge industry does everything but force feed them to us).
Now what would be the relevant difference between human beings and other animals that would justify eating other animals but not people? It’s tempting to think that the “yuck” factor isn’t an arbitrary matter of taste when it comes to eating other humans, and certainly the bond of kinship is an important one. We do tend to protect those most closely related to us. So, perhaps, if it isn’t an arbitrary choice to eat other animals, then the cultural taboo against cannibalism is a sufficient reason to not eat other humans. But that taboo doesn’t justify our eating of other animals and we still need a non-arbitrary reason for eating them.
Could that non-arbitrary reason be that other animals can’t talk? or reason? or build buildings?or create works of art? or any of the other things we think humans are uniquely capable of? No, those reasons, taken one at a time or taken all together, are not non-arbitrary reasons which will justify our eating other animals. In fact, employing those reasons would be just stacking the deck against them. Perhaps if we look this from a different angle, what I am trying to say will be more clear.
Suppose that we ask Which qualities do women lack such that they should receive lower pay than men who perform the same jobs? Now, supposing that women are as qualified as men and are able to perform equally to men, then it would be arbitrary to say things such asMen deserve more pay because they are stronger, or Men deserve higher pay because on average they are taller. Both of these things may well be true, but since neither thing is relevant to the performance of the job in question (remember, we posited that the women were as qualified as and performed as well as men). So, even though those differences might attend, they are not relevant as to whether women in this case ought to be paid equally to men. Moreover, there is a certain circularity to the reasoning in the first place. It is a condition of the human male to be, on average, stronger and taller than the human female. So to then say, Men are worth more because on average they are taller is just to say Men are worth more because they are men. That’s no reason at all.
Differences in attributes are not necessarily accompanied by any differences in moral value or worth. A short and gentle man has the same value as a living being as does a tall and robust one; a woman has the same value as a living being as does a man. So it is when comparing humans to other animals. The human animal on average is more suited to performing well on human intelligence tests, but that says nothing about the value of other animals as living beings. A grizzly bear or an orca has greater strength than any man, but that says nothing about the value of men as living beings.
So, just because other animals may not possess the exact same attributes as do human animals, that doesn’t mean that other animals therefore have less moral value or worth than do humans. Attributes such as language or the ability to reason don’t have anything to do with moral value. No-one should seriously believe that a human being would have less moral value just because she happened to be born without the ability to speak, hear and talk. Neither should anyone seriously believe that intelligence or ability to reason confers moral value – the hopelessly mentally incompetent are still entitled to live the best lives available to them. It would be arbitrary to decide to kill other animals for reasons which would not justify the killing of human animals. Therefore it is an arbitrary practice to kill other animals and we ought not to kill other animals.
But certainly plants are living things and even the most dedicated vegan must benefit from the deaths of at least some plants in order to live? What is the relevant difference between plants and all the animals of the world that makes it such that it is morally acceptable to kill and eat plants but not other animals? What makes the choice to kill plants not also an arbitrary one?
It is this: Plants are not the sorts of beings which have experiences of life which plants care about.
Whatever else we may say about the lives and deaths of plants, plants do not possess any of the biological structures which we know with near certainty would be necessary for plants to be able to have an existence which contains awareness. Therefore, we know with near certainty that plants do not experience life. For example, we know that plants have leaves which turn into the sun not because of any desire to do so. The leaves of plants turn into the sun despite the fact that plants have no thoughts or beliefs about the sun at all. Additionally, we know tha plants do not conceive of any “self”, because plants are not the sorts of beings who have conceptions; plants are not living beings, plants are living things. Because plants don’t know what it is “to be”, because plants cannot know or believe anything, then plants have no interests in living or in not being harmed. Therefore, plants cannot be harmed – at all – in the same ways other animals can be harmed.
Other animals can be harmed in the same ways we can be harmed.
Other animals are the sorts of beings who have experiences of their own lives which they care about. Whatever else we may say about the lives and deaths of other animals, they do possess many of the very same biological structures and attributes which we know with near certainty are necessary and sufficient for us to be able to have an existence which contains awareness. Therefore it is reasonable to say we know that other animals have experiences and care about them; they prefer to live in order that they can continue experiencing.
Just as human beings can be harmed – either by having their ability to have experiences restricted in some way, or having the possibilities for their experiences removed altogether – other animals can be harmed too. Locking a human being in a closet for days on end would harm them by limiting their freedom to have the experiences they might otherwise prefer. Cutting off a human being’s arm would harm them, by cutting of their abilities to have some experiences. Killing a human being would harm them, by denying them any opportunity to have experiences altogether. In the same ways, other animals can also be harmed by denying them their liberty, compromising their bodily integrity, or killing them. Just as we ought not to harm other human beings, we ought not to harm other animals either, because they have the same desire as we do to not be harmed, and because we have no compelling relevant reason to.
There is a final question which ought to be answered. Are ALL other animals the sorts of beings who ought not to be harmed? In other words, is every other animal in the world the sort of being who has experiences which they care about? Are some other animals more like plants than they are like animals? We don’t know. Perhaps simple worms and mollusks don’t care about the experiences they have. Perhaps some other animals don’t have anything even close to experiences in the first place. There are bound to be difficult cases. Considering that our decisions about these cases are literally matters of life and death, perhaps we ought to err on the side of caution. But, when it comes to almost every other animal human beings we routinely interact with, we know that they are the sorts of beings who care about the experiences in their own lives. To harm or kill them would be an egregious error itself.
Dogs care whether they have food and water. Cats care whether they have warm and dry places to sleep. Cows care whether they get to live the lives which their natures give them (and to not have those lives cut short in the slaughterhouse). Chickens care whether they get to keep the beaks they were born with and it matters to them that male chicks get to live (despite their having no value as egg-layers). Dolphins and whales, blue-fin tuna and mackerel, mako sharks and octopuses all care whether they get to swim free in the waters of their births. Simply, we ought to let them and there is nothing arbitrary about any of this.