In the previous chapter, I argued that all beings who have welfare and agency interests that can possibly be frustrated qualify as generally vulnerable. Furthermore, I claimed that some groups may be particularly vulnerable in some situations and thus need special protection and additional attention. I identified those beings who are more likely to have their legitimate claims unjustly considered or discounted by moral agents as particularly vulnerable. This may be due to sheer neglect or ignorance, biases and prejudices, or malicious intentions. That is, some groups are comparatively less likely to be given what they are due, and they thus qualify as particularly vulnerable groups which should be afforded more protection or attention.

What an individual or a group is due depends on both their characteristics and the context. For example, children and disabled persons may have specific claims that differ from those of typical adults. To list a few, children have a claim to education and schooling, while disabled children have additional claims depending on their disability, such as accessible school buildings or adapted learning materials (textbooks written in Braille, for example). At the same time, the particular setting may alter an individual’s claims. To give an example, healthcare practitioners taking care of highly infectious patients during an epidemic have an additional claim to personal protective equipment, and may refuse to work if this claim is not met. Similarly, being a refugee in a foreign country may also lead to additional claims, such as access to housing, healthcare, and translation services.

Thus far, I have primarily discussed human vulnerability and its ethical implications. In what follows, I turn to animal vulnerability, with regard to the following question: are animals, in general, vulnerable beings? I proceed in four steps: first, I assess whether the conditions for ascribing vulnerability—namely, the possession of agency and welfare interests that could be thwarted—can be applied to some animals. I answer this question in the affirmative. Second, I identify animals’ most important welfare and agency interests: an interest in the absence of hunger and thirst; an interest in the absence of suffering, such as pain, injury, and disease; an interest in expressing and pursuing normal behavior; an interest in the absence of discomfort, fear, and distress; an interest in leading a self-determined life; and an interest in continued existence. Third, I discuss whether these interests represent legitimate claims on animals’ part that ought to be duly considered by moral agents. I defend the view that moral agents do indeed owe animals certain direct duties, and that speciesism—that is, a form of discrimination based on species-membership—must be rejected. Furthermore, I argue that when evaluating animals’ interests, moral agents must apply the principle of equal consideration: equal and relevantly similar interests should be given equal weight, regardless of whose interests they are. Fourth, I conclude that animals’ basic interests, as outlined above, are legitimate claims that should be fairly considered by moral agents. This list of basic claims will serve as the basis for the following chapters, in which I will examine whether some animals should be regarded as particularly vulnerable in certain contexts and situations.

4.1 Animals: Universally Vulnerable Beings?

Are animals generally vulnerable beings? That is, do at least some animals fulfill the conditions for vulnerability ascriptions outlined in Chap. 3? To answer this question, we first need to investigate whether animals have welfare and agency at all. In the 1970es, philosophers debated whether or not animals have interests at all (for a discussion see, e.g., Frey 1977; McCloskey 1979). Given our current knowledge, however, it is now widely accepted that sentient animals (animals who are able to feel something)Footnote 1 have welfare interests that could be thwarted: it is in the interest of sentient animals to satisfy their basic desires and needs, such as for adequate nourishment, shelter, water, health, and rest, as well as to avoid mental and physical distress. If these interests are not satisfied, the animals usually experience some form of harm. Minimally, sentient animals have welfare interests and thus fall within the group of generally vulnerable beings: their lives can become better or worse for them, and they care about how they fare in life—they prefer to be better off than worse off. Animal welfare, in general, amounts to the satisfaction of basic biological and psychological needs. This satisfaction should be enduring—ideally throughout the animals’ entire life. “The good life” for animals thus depends on the enduring satisfaction of their most important welfare interests.

A few words about fish and insects. For a long time, it was assumed that fish were incapable of suffering. However, recent research suggests that fish likely experience pain in a manner similar to other vertebrates (Sneddon 2019). In addition, some fish have complex cognitive capacities such as memory; they can use tools; they form social bounds; they recognize themselves and each other; they even cooperate (Brown 2015). That is, fish have welfare interests, at the very least, and perhaps additional interests related to their agency. Consequently, we can add fish to the list of animals fulfilling the conditions for vulnerability ascriptions.

The case of insects is more complex. It is still an open debate whether insects are conscious and sentient beings, and disagreement persists about the methodological approach needed to settle this question once and for all (Birch 2020). The answer to the question “What is it like to be an insect?” is disputed, and it is unclear whether insects can experience pain, distress, frustration, happiness, and the like. For example, a study showed that injured bees who were offered both a pure sucrose solution and a sucrose solution with morphine did increase their liquid intake, yet did not show a preference for the solution with the analgesic. The authors of the study concluded that more research is needed to determine whether insects can feel pain, for example, by involving behavioral observation (Groening et al. 2017).

However, if future empirical research were to determine that insects have welfare and agency interests which can be frustrated, then we would likely consider them a particularly vulnerable group. After all, insects are bred as a source of food in many countries, and they are frequently regarded and treated as a nuisance and killed without a second thought (e.g., to protect crops). Their use in experiments is rarely regulated. If it turned out that insects consciously perceive what happens to them and experience frustration, pain and distress, then we would have to admit that our ignorance about them and their capacities rendered them particularly vulnerable. We would have to completely change the way we treat and consider them in many domains. However, for the purpose of this book, I will focus on animals who are clearly sentient, such as mammals and fish, provisionally setting aside ethical considerations about insects.

Most, if not all, sentient animals are unable to articulate what is in their interest and what matters to them, contrary to most humans who are generally capable of verbalizing their interests. As a consequence, one might say their interests do not really matter, as we can never really know what is in their interest. Note, though, that many animal species can indeed show what is in their interest and what they care about through their actions. For example, by actively avoiding injury and predation, animals can show us that they care about their life and welfare, even though they may be incapable of expressing this with words as humans do. Furthermore, by seeking out the types of food they want to eat and by attempting to preserve family bonds, animals manifest their preferences and what matters to them.

If the welfare interests of sentient animals are frustrated, these animals incur harm and consequently often suffer—as do humans in similar situations. We have to distinguish here between brief, slight pain, and pure suffering. Not every painful event in an animal’s life constitutes suffering and is detrimental to its welfare interests. On the contrary, briefly painful vaccine injections, for example, may in some cases be favorable to the overall welfare of the animal. “Suffering,” as I understand it here, denotes rather long and intense pain or distress endured by an animal.

So far, I have primarily discussed conscious and sentient animals’ welfare interests. A more controversial question is whether animals also have agency interests. I previously defined “agency interests” as interests in pursuing the life one wants, by following one’s individual values, main goals, principles, and beliefs—that is, the interest in actively choosing the life one wishes to live in accordance with one’s values, goals, and beliefs. Individuals usually strive to protect their values and aims as well as their freedom of choice and autonomy. Agency interests thus cover a larger span than a mere interest in autonomous decision-making (whereby autonomy is understood as self-governing actions). Both autonomy and freedom of choice are aspects of agency, but not the only ones: following one’s values, goals, and beliefs form another crucial part.

The question is then whether animals sometimes intentionally pursue actions in view of goals or hold values that can be thwarted, similarly to humans. That is, are animals active agents who shape the course of their own life? And if so, what kind of goals, values, and aims do they pursue? In the case of humans, we may hold personal values, such as leading a self-determined life or wishing our family’s well-being—and we choose suitable actions to realize these ends. Similarly, some animals also act according to what we perceive to be values and goals. Animals may, for example, strive for an “advancement in a social hierarchy, collection of a harem, protection of the newborn, and in some species (wolves and geese, for example), raising a ‘family’” (Feinberg 1984: 59). Furthermore, some animals value freely choosing with which animals (and humans) they interact, and others aim to defend and even increase their territory. Although animals may not be able to consciously utter or frame such goals and values, they show that they care about them through their actions. Thus, some animals have some goods and values they wish to attain, although they may not be able to consciously frame them.

One might object here that animals may value cultivating their relationships, raising a family, advancing in the social hierarchy, defending their territory, choosing how they spend their time, and the like, but that none of these interests really represent agency interests. After all, animals may just pursue these goals instinctively, as they are incapable of consciously revising and changing their values, goals, beliefs, and the like—that is, animals lack the capacities relevant for autonomous agency (Cochrane 2012: 11). The underlying assumption is that agency interests must, by definition, be consciously held and consciously alterable. To give a (rather trivial) example, I may want to eat a chocolate-peanut cake, which is a first-order volition or preference interest. However, I may want not to want to eat this cake because it is unhealthy, because I want to lose weight, or because I know that I am invited to a dinner party in half an hour. Thus, I can decide to refrain from eating chocolate cake and instead give priority to some more important value or aim in my life, such as maintaining good health (a long-term goal) or leaving room in my stomach for more food later on (a short-term goal). One might argue that animals lack such a distance from their goals and values or are incapable of revising them, and that they thus lack the reflective capacities necessary for having agency interests.

However, at least some animals seem capable of revising their primary desires, interests, preferences, and aims: they are capable of not wanting some good X in favor of some other good Y. That is, some animals prioritize some desires over others, which shows that they actively choose what interests they deem more important compared to others. This indicates that many animals are not solely led by pure instincts, but actively choose which actions they want to pursue and which ones they regard as worthier of pursuit at a certain moment of their life. Pigeons, for example, are able to revise their desires and reverse their preferences in order to gain a more preferable food portion for which they have to wait a longer time (Ainslie and Herrnstein 1981). The same applies to cuttlefish (Billard et al. 2020). Similarly, other animals collaborate (and consequently share their ration) to obtain tastier food instead of a direct but smaller reward or no reward at all. Elephants, for example, waited up to 45 seconds for other elephants in a difficult task because they were aware that if they moved a rope by themselves, they would not receive the award they desired (Plotnik et al. 2011). Rats prefer to help other rats in pain or trouble instead of receiving a highly enjoyed food reward such as chocolate, and they also deny themselves the reward if it inflicts pain on other rats (Ben-Ami Bartal et al. 2011; Hernandez-Lallement et al. 2020). The same was found for monkeys (Masserman et al. 1964). Some birds—such as magpies—are more likely to share their food with their conspecifics who have none, which shows prosocial behavior (Massen et al. 2020). These examples illustrate that some animals actively choose between options, selecting the one they deem more valuable at a specific moment. They are capable of prioritizing some desires, goals, and interests (such as helping others) over others (such as getting food as a reward for only themselves), and they thus actively choose which goals they want to pursue at a given moment.

To summarize, many animals have not only welfare interests, but also agency interests. That is, they have values and goals they actively pursue through their actions. Furthermore, some animals are capable of prioritizing some desires over others, and they act accordingly. If animals are thwarted in the satisfaction of their agency interests, in most cases they incur harm—in other words, the frustration of the agency interest has a harmful impact on the animal’s welfare. For instance, if we impede animals from having those social interactions with conspecifics they want to pursue, they may experience distress or even suffering. Conversely, in many cases the satisfaction of animals’ agency interest has a positive influence on their welfare.

4.2 The Basic Interests of Animals

In the previous section, I established that some animals satisfy my definition of vulnerability: they have welfare and agency interests that could potentially be thwarted. The question now is: what is the exact nature of these welfare and agency interests? After all, welfare and agency interests represent large classes of interests, and need to be fleshed out. This is important, as understanding the basic interests of animals will help to determine what claims animals potentially have. These claims, in turn, are relevant to whether some animals are particularly vulnerable in some contexts, such as in research, in agricultural settings, and in the wild—topics broached in Chaps. 5, 6, and 7. Furthermore, we need to establish whether these interests depend on the characteristics of individual animals, or whether all animals of the same species share the same interests. To begin, I analyze animals’ welfare interests, and then I will turn to their agency interests.

There are some basic, fundamental interests that all vulnerable animals share. A useful starting point for determining animals’ welfare interests are the “Five Freedoms of Animal Welfare” developed by the UK Farm Animal Welfare Council FAWC in 1979 (Farm Animal Welfare Council FAWC, Website archived on 2012). These five freedoms are:

  1. 1.

    Freedom from hunger and thirst—by ready access to fresh water and a diet to maintain full health and vigor.

  2. 2.

    Freedom from discomfort—by providing an appropriate environment, including shelter and a comfortable resting area.

  3. 3.

    Freedom from pain, injury, or disease—by prevention or rapid diagnosis and treatment.

  4. 4.

    Freedom to express normal behavior—by providing sufficient space, proper facilities, and company of the animal’s own kind.

  5. 5.

    Freedom from fear and distress—by ensuring conditions and treatment which avoid mental suffering.

These Five Freedoms are considered by the FAWC to be essential for establishing animal welfare as well as for evaluating animal welfare. For the current analysis, I suggest reformulating them as interests:

  1. 1.

    Interest in the absence of hunger and thirst

  2. 2.

    Interest in the absence of discomfort

  3. 3.

    Interest in the absence of pain, injury, and disease

  4. 4.

    Interest in expressing and pursuing normal behavior

  5. 5.

    Interest in the absence of fear and distress

More must be said about these different interests. The interest in the absence of pain, injury, and disease (under point three) can be subsumed under an interest in the absence of suffering, broadly conceived: similarly to humans, sentient non-human animals strive to avoid different forms of suffering, such as long-lasting disease, injuries, and pain. The interest in the absence of discomfort and the interest in the absence of fear and distress (points two and five) can be combined. They do not amount to suffering, but rather lighter forms of distress and discomfort which may negatively impact the animals’ welfare. Furthermore, animals should not only have the opportunity to express “normal” behavior but also enjoy possibilities to pursue such behaviors. The list of interests can be adapted and rephrased accordingly:

  1. 1.

    Interest in the absence of hunger and thirst

  2. 2.

    Interest in the absence of suffering (pain, injury, and disease)

  3. 3.

    Interest in expressing and pursuing normal behavior

  4. 4.

    Interest in the absence of discomfort, fear, and distress

These are basic interests which strongly influence and determine animals’ welfare, and consequently their flourishing. They constitute preconditions for the possibility of living a satisfactory life. They are not frivolous interests, but rather basic ones that persist over time and contribute to the animals’ well-being.

One may wonder whether there are species-dependent differences regarding these interests, and whether individual animals can have interests that differ from those of their conspecifics. Some interests are indeed universally shared by all animals fulfilling the conditions for vulnerability ascriptions, notably the interest in food and water, as well as the interest in the absence of distress and pain. Other interests depend on species-membership. For example, some animal species value living in packs, while animals of other species may be solitary. For some species, play forms an important part of a good life, while this may be of less importance to other species.

Furthermore, individual animals may have specific interests that differ from the interests of their conspecifics. Such individual differences are especially relevant to the interest in pursuing and expressing normal behavior. What amounts to “normal” behavior may differ among individual animals of the very same species. That is, individual animals may have preferences and interests that differ from those of their fellow species members. The category of “normal behavior” should thus be understood as “normal” or typical behavior for the individual animal—which may vary from one animal to another. For example, one pig may be very keen on regular exercise such as running; another pig may prefer spending her day sunbathing; a third pig may prefer spending her day socializing with humans or other animals. Insofar as such individual preferences contribute to the welfare of individual animals, they should be taken into account: the animals should be provided with sufficient opportunities to live out their individual behavioral preferences.

Two interests have not been discussed in detail so far: the interest in self-determination, and the interest in continued existence. As mentioned above, some animals have agency interests, and strive, for example, to advance in their social hierarchy. Others aim to defend or even increase their territory. Others still wish to roam freely and explore their surroundings. Beneath these variations, animals share some basic interests related to their agency: to follow their preferences regarding what they eat, whom they interact with, where they go, and what they do. Hence, like humans, many animals have a basic interest in self-determination: they have an interest in freely determining and shaping the course of their life (be it making important choices, or simply following their preferences), as Sue Donaldson and Will Kymlicka aptly explain: animals “have the need and desire to exercise control in their lives—not just to make temporally localized decisions (what we have called ‘micro agency’) about when to eat or to sleep, but also significant decisions about the general shape and structure of their lives (‘macro agency’) concerning where and how they live; who they mate with, live with and associate with; what sorts of activities they learn about, engage in, and pursue mastery of” (Donaldson and Kymlicka 2016: 235). Hence, animals have an interest in determining how their life proceeds—regarding decisions small and large.

There is debate in the literature as to whether animals’ interest in freedom and self-determination is intrinsic or rather merely instrumental (Cochrane 2009a; Garner 2011; Cochrane 2012; Giroux 2016; Wilcox 2020; Healey and Pepper 2021). This debate is not currently germane to the arguments presented here, however. What is relevant here is that at least some animals have an interest in determining the course of their life by and for themselves, regardless of whether this interest matters merely instrumentally for the sake of an animals’ well-being or purely intrinsically.

A second interest not mentioned in the list of the Five Freedoms is an interest in continued existence, as the Five Freedoms were established as a list about farm animal welfare, for whom death by slaughter is commonly unavoidable. Nevertheless, whether animals have an interest in continued life is a fundamental question which must be addressed, since it has an impact on how we are permitted to use animals and if we are allowed to kill them.

Indeed, death amounts to an irreversible deprivation of the possibility of future pleasurable experiences, and thereby of one’s most important good, namely one’s life. That is, death is a harm by deprivation: it deprives us of the possibility of any future experiences (Sapontzis 1987; DeGrazia 1996; Regan 2004; Rollin 2006). As Tom Regan states: “death forecloses all possibilities of finding satisfaction. Once dead, the individual who had preferences, who could find satisfaction in this or that, who could exercise preference autonomy, can do this no more. Death is the ultimate harm because it is the ultimate loss – the loss of life itself” (Regan 2004: 100).

Thus, death forecloses all future opportunities to satisfy one’s interests, which is harmful. The “badness” of ending an individual’s existence is proportional to the amount harm it causes—that is, the more it deprives the individual of. This deprivation must not be understood in terms of pure lifetime duration that is lost, however; for instance, we usually deem the death of an adolescent who had made long-term plans for her life worse than the death of a baby directly after birth. That is, the quality and intensity of the lost time as well as the number of future interests that are frustrated also count. This means that identity over time matters—how much we are connected by psychological continuity to our own future and plans. Jeff McMahan called this the “Time-Relative Interest Account” (McMahan 2002: 194). It can explain why the death of a teenager is worse than that of an embryo (although the latter loses more lifetime, if we take the average lifetime of an adult as our basis), or why a young person may have much stronger interests in some future pleasurable events than a ninety-year-old person. Death does not usually represent the same harm by deprivation to these different individuals; rather, death is worse according to how much one is connected to plans and anticipations of one’s own future. These considerations will become more relevant to the case of animals in the following chapters, in which I discuss the killing of animals for meat or medical research.

Animals, too, can be harmed by death, as death deprives them of all the future goods they could have experienced. If we kill a dog, for example, we deprive her of future enjoyable interactions with other dogs and her human companion, such as her daily walks or opportunities to frolic on the beach. The same applies to other animals, such as pigs and cows: by killing them, we deprive them of their family bonds, pleasant future moments, and the goods they normally enjoy throughout their life. That is, the interests of animals are frustrated when they are irrevocably prevented from enjoying potential future experiences.

To sum up, sentient animals have a basic interest in continued existence. This interest persists and exists even if animals may not be consciously aware of this interest or be able to conceptualize or express it. This lack of awareness does not pose a problem, as Alasdair Cochrane illustrates: a young child may not be aware that she is constantly inhaling oxygen and exhaling carbon dioxide; nevertheless, “it would be strange to say that she has no interest in breathing, for breathing straightforwardly benefits her. In light of this, it is plausible to claim that sentient animals possess an interest in continued life if it can be shown that continued life benefits them” (Cochrane 2009b: 437).

The same view—that animals do not have to be conscious of their interest in continued existence in order to hold this interest—is also defended by David DeGrazia. He claims that death harms animals by depriving them of valuable opportunities which continued existence would have made possible. It does not matter whether animals can consciously grasp the concept of death or the value of their own existence (DeGrazia 2009: 161).Footnote 2

Thus, it seems reasonable to add both the interest in self-determination and the interest in continued existence to the list of animals’ basic and most important interests:

  1. 1.

    Interest in the absence of hunger and thirst

  2. 2.

    Interest in the absence of suffering (absence of pain, injury, and disease)

  3. 3.

    Interest in expressing and pursuing normal behavior

  4. 4.

    Interest in the absence of discomfort, fear, and distress

  5. 5.

    Interest in self-determination

  6. 6.

    Interest in continued existence

This updated list represents animals’ most important interests, yet two questions remain open. First, it is unclear whether these interests represent legitimate claims by animals that should be taken into consideration by moral agents—a question to which I turn in the next section. Second, to what degree do these interests still count if they conflict with the interests of humans or other animals? This question will be discussed in Chaps. 5, 6, and 7.

4.3 The Moral Status of Animals

As shown in the preceding section, some animals have at least six basic welfare and agency interests: the interest in the absence of hunger and thirst; the interest in the absence of suffering; the interest in pursuing and expressing normal behavior; the interest in being free from discomfort, fear, and distress; the interest in self-determination; and the interest in continued existence. But are these interests of moral importance? Are moral agents obligated to take them into account, and if so, how much weight do they have compared with human interests? That is, do these interests constitute legitimate claims by animals, requiring duties of us as moral agents?

To answer these questions, it is necessary to recall the conditions for claims I outlined before. Individuals have a claim if they have an important interest and there is a moral agent who has the power to consider and eventually satisfy these interests (welfare or agency interests) and who at the same time has a duty correlated with these interests. Thus, for an interest Z to become a legitimate claim Z requires that there be a moral agent with the power over the satisfaction of Z and a duty to consider Z in his or her moral deliberation. Indeed, moral agents do sometimes have power over the satisfaction or dissatisfaction of animals’ interests. For example, we can decide whether or not to eat animals, to torture them for our pleasure, to keep them in small cages, to feed our companion animals or to let them starve. But do we have a duty to undertake some of these actions and to refrain from others?

Answering this question presupposes that we determine the moral status of animals. For an individual X to have moral status, as I understand it here, presupposes that X counts morally for his or her own sake (i.e., it matters to X how we treat X) and that we owe something to X—duties of fair consideration, for example. Thus, there is a difference between merely counting morally and having moral status: the reason why I should not carelessly destroy artwork, for example, is that it has value for myself or others—we have indirect duties with regards to the artwork; by contrast, I should save a drowning child for her own sake, as I owe her this duty directly (not to her parents, say). While the child has moral status, the artwork does not. Thus, I should take some entities (such as precious artworks) into account—I have duties regarding them—but I owe something to those who have moral status directly. In which category do animals fall?

Properties that determine moral status can be called status-conferring properties (McMahan 2005: 355). To be sure, one could argue that animals do not count for their own sake—that is, they do not possess any moral-status-conferring properties at all—and so we only have indirect reasons to consider them morally. For example, it is widely accepted that we should not torture animals gratuitously, but it has been suggested that we do not owe this directly to the animals themselves, but only to other humans. This is the indirect duty view. The German philosopher Immanuel Kant is a famous proponent of such an account. According to Kant, animals exist only as means, not as ends-in-themselves and for their own sake. Our duties toward animals, therefore, are solely indirect duties owed to humanity as such (Kant 2013: 212). That is, according to this view, animals do not matter morally for their own sake; rather, they are only worthy of moral consideration insofar as humans have duties toward each other. Contrary to animals, humans are moral persons, ends-in-themselves, imbued with dignity. Humans are capable of autonomous decision-making and of making their own moral laws. Thus, according to Kant, the capacity for autonomy and moral agency is a moral-status-conferring property. Animals, on the other hand, have the status of mere things and therefore only a price, not worth. They are incapable of making moral laws and thus cannot demand that other agents obey them—this capacity is unique to those endowed with rationality. According to Kant, we owe direct moral consideration only to rational moral agents—and consequently not to animals.Footnote 3

Kant’s reasoning illustrates a tendency in the history of philosophy. Many different properties have been proposed as candidates for conferring moral status: the capacity to use language, moral agency, self-consciousness, and rationality, to name just a few. But why are these properties relevant to moral status? It is far from clear why such primarily rationalistic and cognitive properties should determine moral status. As Sunaura Taylor argues in Beast of Burden: Animal and Disability Liberation, the reliance on such properties to determine moral status amounts to ableism, that is, discrimination against people with a disability: “When neurotypical and able-bodied human capacities are used as the measure of a being’s value, both nonhuman animals and disabled human beings lose out. The characteristics that humans have used to measure cognitive capacity are no doubt signs of a certain kind of complex cognition, but they are not necessarily the only ways to measure intelligence, let alone value or worth. What’s more, the criteria are both anthropocentric, because they reward only recognizably human capacities, and ableist, often leading us to discount the abilities of those with disabilities” (Taylor 2017: 72).

Indeed, disabled individuals historically were—and currently still are—frequently victims of ableism. Previously, I identified as “particularly vulnerable” those who face a decreased likelihood of having their basic claims taken into fair and impartial consideration—due to negligence, biases, prejudice, ignorance, and the like. Clearly, many disabled individuals can be considered particularly vulnerable in Western societies: their valid claims are often overlooked or insufficiently met. To give a few examples: cognitively disabled individuals are often denied political participation, despite their being perfectly capable of voting or running for office; physically disabled individuals are often denied social participation due to their environment’s having been construction in an inaccessible and maladapted way. If one is in a wheelchair and/or blind, participation in public school may be difficult, if the schools fail to provide what one claims for accessibility—namely, entrance ramps, elevators, and other equipment and adaptions that would allow one to follow the lessons and take notes in Braille. That is, many disabled individuals face a decreased likelihood of being given what they are due. As a consequence, they can be deemed a particularly vulnerable group in need of special attention to ensure that they receive what they are due.

As Sunaura Taylor has shown, it is unclear why primarily cognitive capacities such as rationality and self-consciousness should confer moral status. After all, many animals have astonishing capacities that humans lack: some animals are highly agile and others can reach extreme speed. Still others communicate with echolocation. And some animal species have an incomparable capacity to smell things. Nonetheless, we do not regard such qualities as determinants of moral status—likely because humans would then miss out.

One might accept this line of reasoning, but still reject the view that moral agents owe direct moral duties to sentient animals. One might advance the position that human beings have a different moral status than animals because of their membership of the human species—independently from their specific properties, capacities, abilities, and characteristics. Such views usually presuppose that membership of the human species per se justifies special treatment and a corresponding inviolability of basic rights or claims. The view that the members of some species matter more, in moral terms, than the members of other species is called speciesism. The term was originally introduced by Richard Ryder and taken up by Peter Singer, who presented the first detailed analysis of it in his book Animal Liberation: “Speciesism – the word is not an attractive one, but I can think of no better term – is a prejudice or attitude of bias in favor of the interests of members of one’s own species and against those of members of other species” (Singer 2009: 6). Singer makes an analogy between speciesism, racism and sexism: both racism and sexism are unjustified discriminations based on criteria which are irrelevant to moral consideration—namely, race and gender. In turn, non-speciesists claim that discrimination based on mere species-membership is morally problematic because species-membership is a purely biological property which is irrelevant from a moral perspective.

Most animal ethicists usually do not put much effort into defining speciesism; they concentrate instead on its different forms and its moral implications. But it is important to define this notion properly to understand what speciesism is and what it entails from a moral perspective. Oscar Horta, one of the few authors to offer a well-developed account of speciesism, defines it as “the unjustified disadvantageous consideration or treatment of those who are not classified as belonging to one or more particular species” (Horta 2010: 244). That is, we are not only speciesist if we deem some interest X of humans more important than the very same interest X of animals. We also act in a speciesist way if we treat some animal species much better than others for an arbitrary reason. For example, it is speciesist to accord greater protection to elephants and pandas than to pigs and chickens simply because we find the former more “majestic” or cuter than the latter.

According to Horta’s account, to defend a speciesist attitude is always and necessarily a morally problematic position, as the word “unjustified” in his definition suggests. Horta provides a formal framework for understanding speciesism, but he does not show in detail exactly why it is morally reprehensible. The reason is the following: speciesism is wrong because it discriminates on the basis of a purely biological property, namely, species-membership (Jaquet 2020). That is, speciesism falsely begins from the assumption that a purely biological criterion—namely, species-membership—is morally relevant. And as a consequence of speciesist discrimination, animals are frequently denied what they are due. But what does non-speciesist consideration imply, in practice? As outlined above, speciesism entails “an unjustified disadvantageous consideration or treatment” (Horta 2010: 244). Conversely, for a non-speciesist treatment of animals, one would have to consider their interests in a non-disadvantageous way—on a par with relevantly similar human interests. Treating animals fairly means that equal or relevantly similar interests—be they held by humans or animals—ought to be considered alike. This is called the principle of equality, or the principle of equal consideration of interests (Singer 2011: 20). According to this principle, the same consideration should be given to equal amounts of pain or suffering experienced by animals and by humans, other things being equal. David DeGrazia formulates this principle as follows: “If A judges that interest X of a being B has moral weight W, A must judge that (relevantly similar) interest X of beings relevantly similar to B has W” (DeGrazia 1993: 19). By applying this principle, and considering pain and suffering of equal intensity as equally bad wherever they occur, moral agents avoid discriminating based on species-membership.

One may wonder here whether similar interests must always be considered similarly: do we not sometimes have relationships that allow us to circumvent this principle and give priority to those close to us? If an accident occurs, for example, I may be allowed to ease the pain of my daughter before, or instead of, the same pain with the same intensity in another child or an animal with whom I have no relationship. This is not because there is a difference in the importance of said pain; rather, I value (probably rightly) my personal relationships more and am thus allowed (or in some situations, maybe even morally required) to give priority to those close to me, due to special relationships, resulting in special duties.

Importantly, equal consideration of interests does not entail equal treatment, but rather equal consideration of relevantly similar interests. In practice, this may result in different treatment, depending on the being whose interests at are stake (Singer 2009: 2). After all, equally considering a pig’s interest in well-being with a human’s interest in well-being will doubtless result in very different treatments: we may have to provide the pig with entertainment possibilities and mud areas, while humans have interests that pigs lack, such as access to education or the liberty to marry whomever they wish.

The question, though, is whether animal and human interests can in fact be compared. One may argue that humans’ complex mental life renders the very same amount of pain worse for them than for animals: humans can reflect upon the pain, develop anxieties (“It will never end!”) and thus suffer more from it than animals do. On the other hand, most animals lack the knowledge that their pain or suffering might stop at a certain moment in time (e.g., thanks to the administration of pain-relieving medication)—a state of uncertainty which might increase their psychological suffering overall. Furthermore, humans can compare their pain to previous forms of suffering (“It is not so bad after all, I have experienced worse!”) and distract themselves from the pain by focusing on something else. Mental capacities to reflect upon suffering thus do not necessarily influence the severity of suffering; instead, the severity of suffering very much depends on the situation and the individual in question. Nonetheless, we can imagine forms of pain and distress which feel equally bad for both humans and animals. In Chaps. 5, 6, and 7, I will spell out the importance of various interests of animals in different contexts—agricultural settings, research laboratories, and in the wild—as well as their respective weights, and I will outline what these considerations mean in practice for our treatment of animals and our interactions with them.

To summarize, the basic interests of sentient animals matter for their own sake: sentient animals can fare better or worse, and they care about how their life goes. Furthermore, moral agents have direct duties toward animals: they owe it directly to animals to take their most fundamental interests into account. Moreover, animals’ interests should be considered in accordance with the principle of equal consideration by those holding power over the satisfaction or dissatisfaction of these interests. The basic interests of animals outlined at the beginning of this chapter thus have the status of legitimate claims.

4.4 The Claims of Animals

So far, I have established that sentient animals fulfill the conditions for vulnerability ascriptions I outlined in Chap. 3. I have shown that sentient animals have welfare and sometimes even agency interests that could be thwarted. I have defended the views that these animals matter morally for their own sake and that moral agents owe them direct duties of consideration. I argued against speciesism and in favor of the principle of equal consideration, which requires that like interests be considered alike, regardless of who holds them. Accordingly, one of the most important duties of moral agents is to fairly consider the interests of vulnerable animals—that is, animals who fulfill the conditions for vulnerability ascriptions.

Therefore, I infer that the six basic interests of animals are not solely interests, but rather have the status of legitimate claims, provided a moral agent can be identified who has power over satisfying or denying them. Consequently, moral agents have a duty to take animals’ legitimate claims into consideration by fairly applying the principle of equal consideration and counting like interests alike. These deliberations lead us to the following list of basic claims of animals:

  1. 1.

    Claim to the absence of hunger and thirst

  2. 2.

    Claim to the absence of suffering (absence of pain, injury, and disease)

  3. 3.

    Claim to express and pursue normal behavior

  4. 4.

    Claim to the absence of discomfort, fear, and distress

  5. 5.

    Claim to lead a self-determined life

  6. 6.

    Claim to continued existence

Note that these claims are not necessarily absolute and need not be satisfied in all cases. In some circumstances, they could be outweighed by more important claims. In other words, the claims listed here are pro tanto claims.

In the following chapters, I examine the situations in which these legitimate claims can be trumped by more important ones. In discussing how my account of vulnerability should be applied, I will address the following questions: are some groups of animals particularly vulnerable in some situations and contexts? Are some—or even all—animal species particularly vulnerable groups? In this vein, I will take a closer look at animals used and killed for food, animal experimentation, and the duties moral agents owe to wild animals.