The last half a century has witnessed a transformation in animal ethics. From the early works of Peter Singer, Tom Reagan, and Paul Taylor in the 1970s and 1980s to recent contributions by Sue Donaldson, Will Kymlicka, and Christine Korsgaard, philosophers have argued that nonhumans have standing in their own right, and that this standing requires us to extend equal consideration to nonhumans. Shelly Kagan's How to Count Animals falls into this trend of defending standing for nonhumans. However, Kagan's central thesis is that the animal rights revolution has gone awry in defending the equal status of humans and nonhumans. Kagan examines and rejects this “unitarian” position, offering instead a “hierarchical” theory, in which the interests of humans are to be weighed more heavily than those of nonhumans. The book is a thorough, insightful, accessible, and immensely rewarding discussion of the kind of relative status we should seek between humans and nonhumans.
Kagan's first task is to defend the claim that animals have moral standing, that is, that they count directly, in their own right (p. 7). He establishes this claim on two grounds, treated independently. First, animals have sentience, understood as the capacity to experience pleasure and pain (p. 12). If one can show that cats can feel pain, Kagan writes, “[n]othing more is required for the cat to have moral standing” (p. 12). Second, animals have agency in the broad sense of the term that cuts the link between agency and stringent interpretations of normative thinking and deliberative rationality. Animals’ agency might not be of the same level as humans’, but even the capacity to have short-term goals and desires matters for standing. As Kagan concludes, “agency of any sort suffices for moral standing of some kind” (p. 30).
This first argument shows the liberating potential of Kagan's book. As he reminds us, “[o]ur treatment of animals is a moral horror of unspeakable proportions, staggering the imagination,” and many current practices would be precluded by Kagan's argument (p. 5). For example, he states that no one considering his arguments is “required to eat animals in order to stay alive,” which makes meat-eating for those persons “tremendously more difficult to justify – typically, perhaps, impossible” (p. 228).
However, this liberating potential is tempered when Kagan introduces the concept of status, which refers to “sets of normative features governing how we are to treat those things that have moral standing” (p. 8). This means that, though all creatures with sentience or agency have standing and therefore count in their own right, their interests might have different weights because of their different statuses. This is indeed Kagan's conclusion. He proposes a hierarchy which ranks creatures with sentience or agency and attaches different weights to their interests depending on their capacities for meaningful relationships, knowledge, creativity, aesthetic taste, normative reflection, virtue, and spiritual understanding (p. 48). For example, if human interests count for 1.0, then dogs’ interests would count for 0.3. Kagan's final hierarchy includes six layers, from humans to creatures “closest to being full-blown persons (like dolphins, whales, squid, or great apes),” “highly intelligent animals (like dogs, pigs, parrots),” “midlevel animals,” “lower” animals and finally animals with “the least developed psychological capacities,” such as insects and spiders (p. 294). Kagan does not defend this specific hierarchy, but uses it to exemplify the kind of conclusion his argument would achieve when supplemented with scientific knowledge.
The stand-out feature of the book is Kagan's defense of the hierarchical approach, and in particular his rejection of “unitarianism.” According to unitarianism, “there is only one kind of moral status – a status shared by both people and animals” (p. 2). Thus, when the interests of two creatures are considered, “it can make no morally relevant difference whether the given interests are had by a person, say, or a cow” (p. 38). Kagan examines this principle at length, pushing unitarians to specify its meaning. Historically, the principle was used to draw a contrast to equality of treatment (as opposed to consideration). Pigs do not need the right to vote, Peter Singer argued, because they lack the capacities to make use of this right; regardless, their interests should be considered equally.
When contrasted with Kagan's hierarchical approach, the meaning of the principle is harder to specify. On a straightforward interpretation, one would have to consider the same interests as equivalent, regardless of the species. For example, a drowning mouse and a drowning human have the same interest in life. Considering those interests equally leads to an impasse, since they are equivalent – unless, of course, other interests are at stake as well. But, as Kagan points out, this is a counterintuitive conclusion, since we have strong intuitive reasons to prefer the drowning human (p. 40). On the more complex interpretation of the principle, one is also required to consider the level of harm to be incurred by the two drowning creatures. Since the human has far more developed capacities, she would lose more by losing her life than the mouse. If so, according to unitarians, “that fact suffices, all by itself, to justify saving the person rather than the mouse,” without a reference to the notion of status (p. 43).
Still, unitarians need to say more to clarify how harms relate to equality of consideration. Is it that one interest (in life) relates to a web of other interests, such as to see one's children grow and philosophy flourish? If so, it is hard to see the usefulness of the principle, since the interests of individuals of different species would always carry different weights because of said connections, and we would never be considering the same interest. One of the virtues of Kagan's argument is to push unitarians on this topic.
Regardless of whether this challenge can be met, Kagan introduces a final argument against unitarianism, claiming that, despite their theory, unitarians assume the hierarchical approach in practice. According to him, if we acknowledge that the disparity between two creatures is “regular and systematic,” then we should say that there is a “standing presumption” to favor one of them (p. 53). For example, if we prefer the interests of humans to equivalent interests of mice in a variety of situations – when considering the interests in life, movement, and safety – then we can conclude that we have a systematic tendency to prefer humans. For Kagan, this means that humans effectively have a higher status than mice (p. 53). If unitarians’ arguments always give preference to the human, it seems “peculiar to deny that [their] theory is hierarchical, when it tells us to systematically favor one group over another” (p. 55).
While Kagan's arguments against unitarianism are incisive, it is less clear whether the concept of status plays an important role when the theory is applied to practice. It seems to me that reasons stemming from capacities related to sentience and agency are not always the most relevant reasons. For example, if a city council is deciding whether humans should expand their city limits by deforesting a habitat of other species, Kagan's approach would compare the harms created (presumably, the other species’ harms would be accumulated and weighed against the human benefits). It is not inconceivable that, after such a calculation, Kagan's approach would approve human expansion. However, this type of reasoning would neglect some important considerations. In particular, seeing that we are only one species on earth, we might feel the demand to share the world with others, regardless of their capacities. Even if calculations could show that removing an ant colony would be a lesser comparative harm, the question whether we have the right to do so seems undecided. Broader concepts that establish the human place on earth, and in relation to other species, are lacking.
This leads me to a larger point about the need for such intermediary or local concepts to supplement Kagan's theory. Kagan's philosophical approach is intuitionist. Unlike John Rawls's theory of justice or Donaldson and Kymlicka's theory of animal rights, Kagan's hierarchical approach does not introduce intermediary concepts, such as fraternity, reciprocity, cooperation, or citizenship. Instead, the hierarchy consists of figures, such as 0.3 and 0.8, which refer to creatures’ capacities. This is not an important problem in easier cases, where analogous interests of two individuals from different species conflict. For example, during a large-scale emergency evacuation, when time and resources make it impossible to save every creature, it would be reasonable to prioritize human beings over dogs. However, more complicated cases call for intermediary concepts. Take distributive justice. Choosing egalitarianism as his example of a theory of distributive justice, Kagan argues that egalitarian unitarianism requires bringing up the least advantaged creature – let's say a mouse – to an acceptable level of wellbeing (pp. 63–65). He rightly takes this implication to be absurd, but it is not obvious that egalitarian unitarianism has to demand it. Egalitarian theories make use of relational concepts, such as citizenship and reciprocity, and base their claims on these concepts. For instance, Donaldson and Kymlicka argue in Zoopolis (2011) that dogs are contributing political agents and therefore should be treated as part of the society's scheme of social cooperation, with its benefits and burdens. If Donaldson and Kymlicka could not establish this role for dogs, their theory would not lead to the absurd implication that we should bring the wellbeing of mice up to the level of humans. So, the conclusion in question needs relational concepts to be established. It is these concepts rather than the hierarchy of capacities that are at the core of such arguments.
I am not sure that Kagan would wholly disagree with this. His chapter on defense, which includes analyses of hunting, also makes use of intermediary concepts, such as whether the attacker is a deliberate threat or an innocent aggressor, whether the response is proportional, and whether the killing is necessary (pp. 254–57). The hierarchy of creatures is used to determine the weight of such broader considerations. Perhaps one can conclude, then, that the hierarchy of capacities will be crucial in some stark cases, such as that of evacuation, whereas other, more ordinary, examples will have to be decided primarily using concepts specific to the case.
In sum, Kagan could further clarify the relationship between the provided hierarchy and the more local concepts when examining practical issues in animal ethics. However, the book rightly focuses on the ambiguities in the unitarian principle that creatures’ interests should count equally, regardless of their species. His insightful and thorough discussion enriches the tradition of thinking on animal rights and shifts the burden of proof onto unitarians to clarify their main principle and address the alternative theory Kagan puts forth.
