Animal rights is an idea whose time has come.Footnote 1 This book looks at animal rights through the lens—and as a phenomenon—of new human rights.Footnote 2 It revisits a question once famously asked by the philosopher Paola Cavalieri: are human rights human?Footnote 3 In other words, can and should animals have some of the same fundamental rights that have traditionally been reserved for humans in the guise of ‘human rights’?

Not long ago, the very notion of human rights for nonhuman animalsFootnote 4 was easily dismissed as nonsensical.Footnote 5 After all, human rights are considered to be ʻliterally the rights that one has simply because one is a human beingʼ.Footnote 6 On the other hand, Christopher Stone reminded us that throughout legal history, each extension of rights to some new group has been ‘a bit unthinkable’.Footnote 7 When Olympe de Gouges (1791) and Mary Wollstonecraft (1792) first proclaimed the rights of woman in the wake of the 18th century’s declarations of the rights of man, the bold proposition that human rights might also be women’s rights was met with much the same incredulity and ridicule as animal rights are today.Footnote 8 Indeed, Thomas Taylor (1792) responded to Wollstonecraft’s A Vindication of the Rights of Woman with the satire A Vindication of the Rights of Brutes, likening the case for women’s rights to the case for animal rights—of course intended as a reductio ad absurdum. Over two centuries later, we can affirmatively state that women’s rights are human rights,Footnote 9 and we may ask in more earnest: are animal rights the next frontier of human rights?

1.1 Animal Rights as New Human Rights…

1.1.1 What Are Animal Rights?

Animal rights are moral and/or legal rights that protect certain aspects of an animal’s existence, well-being, intrinsic value, integrity, or other interests.Footnote 10 The term ‘animal rights’ tends to be used differently in theory, practice, and common parlance.Footnote 11 In a broad sense, it often serves as an umbrella term that covers any kind of (even marginal) protections for animals. For example, simple animal rights are the weak and oftentimes odd legal rights that animals may be said to have based on existing animal welfare legislation, such as a right to be slaughtered with prior stunning or a right of chicks to be killed by fast-acting methods, such as homogenisation or gassing.Footnote 12 More commonly, however, the notion of animal rights is distinguished from animal welfare law, and conceived as a temporal successor thereof and as a substantive progression therefrom.Footnote 13 In a narrow sense, then, the term ‘animal rights’ is typically reserved for a distinctive and more robust kind of normative protection in the form of basic rights, such as the right to life, liberty, and bodily integrity. These fundamental animal rights are strong legal rights along the lines of human rights that protect fundamental interests and are not easily overridden by countervailing considerations.Footnote 14

This book, like most of animal rights theory, is concerned with fundamental animal rights. In this sense, the idea of animal rights is about ‘universal basic rights for animals’ in virtue of their sentience or ‘selfhood’Footnote 15—as it were, fundamental rights that animals have simply in virtue of being animals. This dominant understanding echoes that of human rights—the fundamental rights that humans are said to have simply in virtue of being human—and connotes what might be cumbersomely called ‘human rights-like animal rights’. Even though animal rights theory has from its inception gravitated towards the natural rights and human rights tradition,Footnote 16 contemporary animal rights discourse has taken a more explicit human rights turn. There is now a growing trend to frame animal rights in the language of human rights, and to assert human rights claims on behalf of animals. As a result, animal rights are today considered among an eclectic group of new human rights candidates.Footnote 17

1.1.2 What Are New Human Rights?

New human rights—or claims to such—are novel (contested) rights that seek to enlarge the ‘protective umbrella of human rights’ beyond the currently accepted catalogue of rights in order to address an extant protective gap or new protective need.Footnote 18 New human rights discourses are a constant companion to the established human rights order. This is because human rights, by their very nature, are subject to evolution and revolution; they carry in them the permanent possibility of generating new human rights or extending old human rights to new right-holders.Footnote 19 For example, women and children were once new human rights-holders, and today, the right to a healthy environment may be considered one of the newest human rights.Footnote 20 Human rights are not static, but rather, in a perpetual state of ‘evolutionary flux’Footnote 21 and in ongoing need of extension, refinement, and revision.Footnote 22 It is this inherent dynamism that enables human rights to respond to changing social, political, ethical, or environmental needs and challenges, and therefore to meet the ‘problems that people face in a modern-day world.’Footnote 23

The present era is often referred to as the Anthropocene—the new human-dominated geological epoch in which humankind has become a central force in shaping the global environment, and in which the destructive and escalating impacts of human activities on planet Earth are becoming evermore manifest.Footnote 24 In the Anthropocene era, humanity is confronted with a number of new existential risks. These stem from a cluster of interrelated environmental and health crises such as anthropogenic climate change, biodiversity loss, and zoonotic diseases—all of which are intimately linked to our destructive and exploitative relationship with animals and the wider natural world.Footnote 25 Contemporary ‘Anthropocene problems’Footnote 26 are profoundly changing the ‘safe operating space’Footnote 27 for human rights, and may give rise to new (non)human rights at the human-animal-environment interface.Footnote 28 It is in this specific historical context that animal rights as new human rights articulations have started to flourish—fuelled not only by an evolving sense of animal justice, but perhaps more so by an acute awareness of ecological pressures.

1.1.3 Are Animal Rights New Human Rights?

At present, animal rights are new human rights claims and as such ‘merely candidates for legal recognition’.Footnote 29 Broadly speaking, we can distinguish three stages in the ‘birth process’ of a new human right: from its intellectual inception (the idea phase), to its gradual reception and consolidation in legal and political arenas (the emergence phase), to its eventual legal recognition and codification (the recognition phase).Footnote 30 Animal rights are currently located in between the first and second stage of this ‘lengthy period of gestation’.Footnote 31

New human rights start out as (oftentimes fringe) discursive articulations by intellectual and political ‘norm entrepreneurs’ expressing a need to develop existing human rights law.Footnote 32 In animal rights discourse, we can clearly discern a human rights turn—a rising trend to articulate and integrate animal rights in the language, concepts, and frameworks of human rights. In animal rights theory, a growing body of scholarship casts animal rights as a ‘necessary dialectical derivationʼFootnote 33 or ‘logical extension of the doctrine of human rightsʼ,Footnote 34 and explores the continuities and interconnections between human and animal rights.Footnote 35 Conversely, the idea of animal rights is gradually permeating human rights theory,Footnote 36 where the ‘universal rights of animals’ are starting to be considered as a possible ‘fourth generation of human rights’.Footnote 37 In animal rights practice, we can observe a push to have animals’ fundamental or human rights legally recognized through legislative or judicial means. For example, a citizens’ initiative in the Swiss Canton of Basel-Stadt demanded a constitutional amendment recognizing the fundamental rights of nonhuman primates (which was, however, rejected at the ballot box in 2022).Footnote 38 Others have attempted to invoke before courts human rights on behalf of captive animals, such as the right to a fair trial,Footnote 39 the prohibition of slavery,Footnote 40 or—such is the litigation strategy of the US-based Nonhuman Rights Project—the right of habeas corpus.Footnote 41 These activities are typical for the first, idea phase of new human rights: scholars engage in fleshing out the conceptual foundations and contours of animal rights, while strategic litigation takes first steps to attain human rights for animals in practice.Footnote 42 Overall, the once quixotic idea of extending human rights to animals is gaining wider traction in the political and legal sphere.Footnote 43

Moreover, marking the beginning of the next developmental phase, there is a nascent but growing global animal rights case law. Over the past decade, some pioneering courts have embarked on a path of judicial recognition of fundamental animal rights, arriving at them either through a dynamic-extensive interpretation of constitutional (human) rights or via a rights-based interpretation of animal welfare law. Most notably, courts in ArgentinaFootnote 44 and ColombiaFootnote 45 have extended the fundamental right to habeas corpus, along with the underlying right to liberty, to captive animals. In another habeas corpus proceeding, the Constitutional Court of Ecuador has recognized a range of basic animal rights as part of the rights of nature.Footnote 46 Meanwhile, the Supreme Court of India and Indian High Courts have developed a remarkable case law recognizing and fleshing out the fundamental rights of animals, such as the right to life, dignity, and freedom from tortureFootnote 47—or the fundamental right of birds ʻto fly in the sky’.Footnote 48 The Islamabad High Court has also affirmed a range of fundamental animal rights, and further underscored their nexus with human rights and the ‘interdependence of living beings’.Footnote 49 Lastly, albeit more tentatively, the Swiss Federal Supreme Court has confirmed the legal possibility of fundamental animal rights in principle.Footnote 50 Suchlike (as yet still isolated) acts of judicial recognition of animal rights correspond with the early stages of the second, emergence phase of new human rights. This stage is characterized by the occurrence of legal activities that are more immediately relevant to the formation of rights, such as courts corroborating the idea of extending fundamental or human rights to animals.Footnote 51

Overall, recent developments in theory and practice suggest that legal animal rights are on the horizon, and that fundamental animal rights may be emerging as a new generation of (non)human rights.Footnote 52 We may thus be at the onset of the next, and perhaps most profound, human rights revolution—a nonhuman rights revolution: the extension of old human rights to a new class of nonhuman right-holders.

However, animal rights have yet to progress into the final developmental stage of new human rights: legal recognition and codification. Until such wider institutional, political, and legal validation occurs, they remain contested claims or ‘wannabe rights’.Footnote 53 Indeed, among the potpourri of new human rights claims, animal rights are particularly controversial, and contestation and opposition to them perhaps strongest.

1.2 … or the End of (Old) Human Rights?

As new human rights claims, animal rights are met with strong resistance, if not ridicule or hostility—especially by human rights scholars.Footnote 54 For one thing, the ongoing expansion and proliferation of human rights has generally given cause for concern.Footnote 55 Critical voices warn against such human rights inflation, as it risks undermining the currency, legitimacy, and universality of human rights.Footnote 56 These concerns may appear even more acute with regard to animal rights, considering the sheer number—billions—of potentially entitled animals and the ensuing exponential growth of new human rights-holders and conflicts.Footnote 57 Moreover, human rights are already under pressure. In practice, they are undermined by widespread and persistent violations, illiberal backlashes, and an implementation or theory-practice gap.Footnote 58 In theory, human rights are an ‘essentially contestable concept’Footnote 59 that suffers from remarkable foundational uncertaintyFootnote 60 and are the target of penetrating critiques and challenges.Footnote 61 As one commentator has put it, ‘Virtually everything encompassed by the notion of “human rights” is the subject of controversy’,Footnote 62 and as a recent review of human rights theory has concluded, there is a ‘diversity of positions … with no prevailing philosophical view even on fundamental issues like what a human right is’.Footnote 63

Amidst the plethora of problems, one seemingly banal assumption has remained relatively uncontested and operative in most of human rights discourse: that human rights are human, i.e., rights held by human beings simply in virtue of their humanity.Footnote 64 In this respect, animal rights obviously differ from other new human rights claims in that they aim at a rights expansion not within but beyond the human species. Animal rights thus challenge a (perhaps the) core axiom of human rights, which may be perceived as a further corrosive trend undermining the viability of human rights. Indeed, against the gloomy backdrop of talk of an ‘endtimes of human rights’Footnote 65 or a ‘post-human rights era’,Footnote 66 the very idea of taking the ‘human’ out of human rightsFootnote 67 and introducing some form of dehumanized,Footnote 68 post- or nonhuman rights might be feared to herald the end of human rights. As Costas Douzinas has summarized these sentiments, ‘to question human rights is to side with the inhuman, the anti-human and the evil.’Footnote 69

This book addresses two sets of objections against animal rights in particular: philosophical or conceptual and political or practical ones. The first group of concerns relates to the conceptual nature of human rights, which one might say is ill-suited to accommodate animals, because it is intrinsically linked to humanity. Any attempt to insert the nonhuman would be incompatible with, and lead to a collapse of, the very concept of human rights. The second group of objections concerns the practical undesirability of extending human rights to animals. It is often assumed that animal rights are bad for human rights and will lead to harmful consequences, such as levelling down the normative status of (non-paradigmatic) humans.Footnote 70 For both types of objections, opposition to animal rights is considered a necessary position in defence of human rights.Footnote 71

This book seeks to defend animal rights against both the conceptual objection (which maintains that only humans can, and animals cannot, have human rights) and the practical objection (which maintains that only humans should, and animals should not, have human rights). It argues that the inclusion of animals under the human rights paradigm is justified on both philosophical and practical grounds; that is, it is conceptually sound and politically warranted for both principled and prudential reasons. In other words, this book seeks to show that human rights need not be predicated on the exclusion of animals, and that tending to animal rights may ultimately help save human rights.

1.3 Something Old and Something New: One Rights

In a nutshell, this book submits that (some) human rights can and should be extended to animals, and advocates the recognition of animal rights as new human rights. It argues that there are compelling conceptual, principled, and prudential reasons for modernizing and expanding the human rights paradigm anew, and for including animals in its protective ambit. Ultimately, this book advances a holistic understanding of human and animal rights as part of the same family of fundamental rights: One Rights, indivisible and interdependent.

The novel term ‘One Rights’ is proposed here as a normative companion to the scientific One Health approach.Footnote 72 One Rights encapsulates the union of (old) human rights and (new) animal rights under a shared normative framework. On this understanding, animal rights are located not alongside or below human rights, but form an integral part of an updated and broadened conception of (post-)human rights. As will become clear throughout this book, the One Rights approach is based on the idea that, for all their nuances and differences, human rights and animal rights share a deep conceptual kinship and practical interdependence. The One Rights approach asserts that in a conceptual sense, human rights are animal rights and animal rights are human rights, and that in a practical sense, protecting human and animal rights in concert promises to yield better outcomes for humans, animals, and their shared planetary home.

1.4 Approach and Structure of the Book

This book brings together the seemingly disparate theories of human and animal rights, and consolidates them under a novel One Rights paradigm. It approaches the question whether animals can and should have human rights through an extensive interrogation of contemporary human rights philosophy and the justifications most commonly advanced therein. The animal question raises foundational issues about the nature and grounds of human rights. ʻWhat are human rights, after all?ʼFootnote 73—and why do all (and only) humans have them? These questions are surprisingly difficult to answer, not least because the concept of human rights is highly indeterminate and ʻnearly criterionlessʼ.Footnote 74 Human rights law—the legal field dealing with institutionalized human rights—is of little avail in finding answers to these fundamental questions. Perhaps because human rights are today so firmly entrenched in international and constitutional law, lawyers take the institution of human rights for granted and rarely feel the need to reflect on its foundations. As Samantha Besson notes, legal scholars tend to treat human rights as axiomatic or ‘self-justificatory, an irreducible value that is not in need of further justification’.Footnote 75 Rather than looking to human rights law, the animal question leads us deep into human rights philosophy, which is tasked with justifying—giving reasons—for human rights.Footnote 76

The philosophical landscape of human rights is marked by a bifurcation into naturalistic and political conceptions. Briefly put, naturalistic conceptions contemplate human rights as inherent moral rights deriving from some abstract human nature, whereas political conceptions centre on the practical functions of human rights as derived from concrete political practice. While naturalistic and political conceptions of human rights are often cast as opposing theoretical accounts, there is good reason to think that this dichotomy might be overdrawn.Footnote 77 Matthew Liao and Adam Etinson argue that naturalistic and political conceptions can be seen as mutually complementing rather than incompatible theories, since they address different aspects of human rights that do not necessarily overlap.Footnote 78 Indeed, naturalistic conceptions are primarily concerned with the nature and grounds of human rights (and with the innate qualities of their individual holders), whereas political conceptions are primarily concerned with the functional role of human rights (and the institutional dimension of their protection).

For the purposes of this book, it seems sensible to adopt a pluralistic approach that takes into account both naturalistic and political conceptions of human rights, in order to fathom both the conceptual and practical side of the animal question. Naturalistic theories, which analyse human rights in terms of their conceptual nature, are more pertinent for illuminating the conceptual issue whether animals can have human rights, whereas political theories, which explain human rights in terms of their practical functions, are more instructive for evaluating whether there are good practical reasons for affording animals human rights. Accordingly, this book pursues a two-pronged analysis that looks at animal rights through the lens of both naturalistic and political theories of human rights. In doing so, it takes a parsimonious approach that is agnostic to the issue of which conception of human rights is correct.Footnote 79 The aim of this book is not to determine the ‘true’ meaning of human rights, but rather, to examine whether animal rights can and should be an integral part of human rights, however properly understood.

Chapter 2 deals with the conceptual question whether animals can have human rights. It examines a range of naturalistic human rights theories in terms of their potential for providing a conceptual home for animal rights. It distinguishes between exceptionalist and non-exceptionalist conceptions of human rights: two families of naturalistic theories—resting on either ‘old’ or ‘new humanism’—that differ in terms of their investment in human exceptionalism and their exclusiveness towards animals. As will be shown, the demarcation from and exclusion of animals is conceptually built-in to the first, exceptionalist conceptions, whereas the second, non-exceptionalist conceptions are only incidentally exclusive but conceptually open to animals. This chapter ultimately argues that the modern human rights paradigm is one of accidental yet inherent transspecies inclusivity, and therefore need not, indeed cannot consistently, be limited to the human species.

Chapter 3 addresses the practical question whether animals should have human rights through the lens of political conceptions and the functions they commonly attribute to human rights. This chapter argues that extending human rights to animals is politically warranted for both principled (intrinsic) and prudential (instrumental) reasons. As a matter of justice, animals deserve and need human rights as a normative response to their experiences of violence, discrimination, and oppression. Moreover, animal rights also serve the indirect function of alleviating some of the gravest human rights threats such as dehumanization and environmental crises, and so have beneficial effects for humans too. This chapter thus challenges the dominant narrative of a principally antagonistic relationship between human and animal rights, and recasts it as one of synergism and interdependence. It argues that in light of their socio-political and ecological interconnectedness, human and animal rights are best protected in concert.

Chapter 4 synthesizes the insights drawn from naturalistic and political justifications of human and animal rights, and outlines the holistic One Rights approach as a new (post-)human rights paradigm for the Anthropocene.

Lastly, an important caveat is in order. The goal of this book is to introduce the novel concept of One Rights, and to substantiate its theoretical foundations along the dominant strands of human rights theory. In doing so, this book seeks to take the first steps towards a post-anthropocentric paradigm shift in the traditionally anthropocentric terrain of human rights. What this book does not aspire to do, however, is to develop a full-fledged and detailed account of One Rights as a legal paradigm. This would include, for example, an examination of what particular (human and nonhuman) right-holders hold which specific rights, what legal mechanisms may serve to resolve rights conflicts, and by what means to operationalize legal institutionalization, implementation, and enforcement. These questions are beyond the scope of this book, and may hopefully be the subject of future research.Footnote 80