Tony Leyh1Tony Leyh is an Articles Editor of The University of Chicago Law Review and a J.D. Candidate in the University of Chicago Law School Class of 2022. He received his B.A. from Eckerd College in 2013 and his Ph.D. from Emory University in 2020.

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In Naruto v. Slater (9th Cir. 2018), Naruto, a Celebes crested macaque from Sulawesi, Indonesia, snapped several “selfies” on wildlife photographer David Slater’s unattended camera. After Slater published the photos, People for the Ethical Treatment of Animals (PETA) filed suit as a “next friend” of Naruto, arguing that Naruto, not Slater, owned the copyright to the photos and was entitled to the proceeds from Slater’s book.

The parties were unable to litigate the merits of this issue, however, because the District Court for the Northern District of California dismissed the case, finding that Naruto failed to satisfy the threshold requirements of standing. In affirming this ruling, the Ninth Circuit confirmed that the district court’s rationale was sound: Naruto lacked statutory standing, even though the macaque, surprisingly, satisfied the requirements of Article III standing (and both were needed to survive dismissal).

Yet determining whether animals satisfy the requirements for Article III standing has a mixed pedigree. In Cetacean Community v. Bush (9th Cir. 2004), the Ninth Circuit held that animals qualify for constitutional standing, reasoning that Article III “does not compel the conclusion that a statutorily authorized suit in the name of an animal is not a ‘case or controversy.’” Moreover, animals have survived as named plaintiffs mainly when their standing goes unchallenged. For instance, in Palila v. Hawaii Department of Land & Natural Resources (9th Cir. 1988), the Ninth Circuit colorfully described the Palila bird, a critically endangered member of the Hawaiian honey-creeper family, as “wing[ing] its way into federal court as a plaintiff in its own right.” Yet later labeling the Palila court’s description as “nonbinding dicta,” the Cetacean court abrogated this unclear conferral of standing to the bird when the issue was raised explicitly.

Indeed, despite the Ninth Circuit’s continued recognition of Article III standing for animals, the Naruto court clearly implies that Cetacean—which established constitutional standing for animals—was wrongly decided and should be revisited. The court’s commentary here both intimates that an internal circuit split is fomenting and raises the larger issues of how to untie the Gordian knot of the suitability of Article III standing for animals.

This Essay suggests pulling some strands to loosen that knot. The essential point is that the substantive goal of providing Article III standing for animals can be achieved in ways that avoid the—to my mind regrettable but—recurrent arguments that courts and scholars deploy against finding that animals satisfy the requirements for Article III standing.

The alternative I suggest is a more capacious approach to determining when humans suffer aesthetic injury, a primary cause of action through which humans currently litigate on behalf of animals’ interests. I suggest that this alternative rests on a conceptually plausible interpretation of aesthetic injury, is less susceptible to the rhetorically potent arguments against Article III standing for animals, and would be equally effective in achieving greater legal protection for animals.

I.  Article III Standing for Animals: Arguments and Goals

The Cetacean court relied principally on a textual argument to justify conferring to animals Article III standing: a plain reading of the “case or controversy” requirement does not necessarily support restricting standing only to humans. Whatever the merits of this argument, animal welfare activists and scholars have provided a more theoretical argument to buttress the eligibility of animals for Article III standing.

The argument focuses on replacing animals’ current legal status as property with a designation of animals as legal persons. Granting legal personhood to animals would allow them to qualify de facto for Article III standing. The allure of this argument begins with appreciating two facts. First, the property status of animals is highly anomalous. No other form of property, for instance, is protected by anti-cruelty statutes. Moreover, several other nations—including Argentina, Portugal, Spain and Switzerland—have denounced the property status of animals. Second, legal personhood is capacious. Historically, membership in the human species has not been sufficient for legal personhood: slaves, women, and children were all once considered property in the eyes of the law.2Bruce A. Wagman, Sonia S. Waisman, Pamela D. Frasch, Animal Law: Cases and Materials 51–65 (2010). Nor is such membership necessary: courts have found corporations, trusts, and ships to be legal persons. Taken together, these two facts suggest both that (1) animals’ nonhuman status is not an absolute bar to legal personhood and (2) the inclusion of animals as legal persons is a reasonable extension of the term.

The goals behind these arguments are twofold. First, there is a clear policy goal. As it currently stands, the only justiciable injuries to animals are those that depend on injuries to humans. If animals qualify for Article III standing, however, the courts can protect the sundry interests of animals, particularly those that are either divorced from or not reducible to human interests. And it is relatively clear that animals do indeed possess interests that are largely nonjusticiable. A robust body of scientific literature testifies that many animals have rich, complex psychological and social lives; those lives can be easily frustrated by unwitting human interference.3See, e.g., Frans de Waal, Good Natured: The Origins of Right and Wrong in Humans and Other Animals (1996); Thomas I. White, In Defense of Dolphins: A New Moral Frontier (2007). Moreover, Martha C. Nussbaum has proposed a compelling framework that tailors a theory of animal welfare to the various interests of animals as determined by each species’ characteristic form of life.

The second goal is largely symbolic. Animals going through lawsuits as named plaintiffs may serve to elevate the awareness of how human actions intertwine with those of animals as well as to nurture a sense of responsibility that humans may have towards animals. The importance of symbolism for animals is not foreign to U.S. courts. The Wild Free Roaming Horses and Burros Act, for instance, protects horses and burros from capture, branding, harassment, and death because Congress recognized these animals as “living symbols of the historic and pioneer spirit of the West” and as “contribut[ing] to the diversity of life forms within the Nation and enrich[ing] the lives of the American people.”

II.  Arguments Against Article III Standing for Animals

The arguments against granting Article III standing fall into two general categories: (1) on a theoretical level, animals are so distinct from humans that their interests either cannot or should not be translated into legal venues, and (2) foreboding practicable difficulties will arise if animals are granted Article III standing.

The concurrence in Naruto obliquely touches upon the first argument. In the context of discussing next-friend standing for animals, Judge N.H. Smith suggests that “[b]ecause the ‘real party in interest’ [i.e. an animal] can actually never credibly articulate its interests or goals, next-friend standing for animals is left at the mercy of the institutional actor to advance its own interests, which it imputes to the animal or object with no accountability” (emphases in original). The general idea here is that an unrelenting skepticism about what interests animals possess prevents courts from adjudicating claims that principally involve animals’ interests.

Matthew Armstrong hosts a more extensive defense of both arguments in the context of criticizing Cetacean’s holding. Regarding the first argument, Armstrong posits:

Laws, by which we preserve [legal] rights, are artificial restraints on the natural impulses of human beings. Reciprocal restraint allows the formation of communities of humans that pursue selfish ends through, if not unselfish, at least tempered means. Not one of the [pro-animal rights] articles cited infra mentions any instance of an animal . . . exercising restraint to the point of forfeiting existence to comply with an abstract agreement. No one has produced an example of an animal even recognizing an abstract agreement. At the very least, then, even if humans extend animals individual rights such as those we enjoy—to life, freedom, property—a human will always be capable of tricking an animal into forfeiting those rights by breaching the contract the animal is not even aware exists.

Putting aside the largely gratuitous and dubious claims about human nature and the purpose of forming political communities, Armstrong’s essential point is that animals are unable to recognize legal rights and, as a result, the attribution of legal rights to them would be improper.

When faced with the obvious rejoinder that plenty of human beings who are incapable of recognizing legal rights are nonetheless afforded them (e.g., infants or intellectually disabled adults), Armstrong attempts to distinguish animals from infants on the basis that infants are presumed to be able to recognize their rights at some point in the future. (He avoids discussion of why intellectually disabled adults are afforded rights.)

Armstrong’s distinction cannot be adequate. Infants are not granted rights on the condition that they will maintain those rights only if they develop the characteristic rationality of human beings. Rooting infants’ legal rights on the presumption of their future rationality is a non-sequitur simply because their presumed development has no bearing on the rights they enjoy as infants. As it stands, the basic point is that an inability to recognize one’s legal rights is not a barrier to possessing them. Explanation of different origins of the inability to recognize rights is irrelevant to whether individuals with such an inability do indeed possess rights.

A secondary argument that Armstrong uses to support excluding animal interests from the courts’ grasp appeals to the special characteristics of human beings. Armstrong asks rhetorically: “If the whole concept of ‘morality’ is nothing more than a human construct, why should it not be species-centric?” Again putting aside the contentious claim about morality, the basic idea is that any charges of speciesism miss the point of how courts work: they are human constructs devised to resolve human conflict, and animals need not appear. This kind of argument is part and parcel with the Naruto concurrence’s worry about animals’ inability to express their interests in the courtroom: animals are just too distinct to have a place in the courtroom.

This reasoning is similarly unpersuasive. Courts undoubtedly are venues to adjudicate conflicting human interests. But that proposition does not entail Armstrong’s conclusion that animals should not be able to access the courtroom. At least since the time of Aristotle, who inaugurated the study of biology by investigating animal lives along the coast of the Greek island of Lesbos, human interests have involved the study of and interaction with animals.4See generally Armand Marie Leroi, The Lagoon: How Aristotle Invented Science (2015). Indeed, contemporary caselaw shows that interest in and care for such animals is alive and well. A New York court, for instance, recently decided who among neighbors is best positioned to care for a cat by considering where the cat would best thrive according to its own interests.

Another way of responding to this secondary argument is to recognize its philosophical imprecision. The idea of allowing animals to sue in propria persona is not a proposal to supplant a court’s focus on human interests in favor of animal interests. Rather, it is a novel and principled expression of a human interest. Scientific evidence abounds showing that animals have rich and nuanced nervous systems and perceptual apparatuses and correspondingly rich and nuanced lives.5See generally de Waal, supra note 3. For better or worse, human beings have positioned themselves to be de facto responsible for those lives.6See generally Martha C. Nussbaum, Justice for Animals: A New Theory of Animal Welfare (forthcoming 2022). Advocating for animals to qualify for Article III standing is an expression of that responsibility. More specifically, this advocacy expresses the worry that the current legal framework is inadequate to address the manifold injuries to which animals are susceptible. As a remedy to this inadequacy, the proposal is to allow animals to sue in their own names so as to ensure that such injuries are not anthropocentrically reduced to human injuries for which remedies may be insufficient.

The other common argument against Article III standing for animals is based on the practical difficulties that would arise if animals had standing. This practical difficulty argument admits of two general forms.

The first form is a variation on what Justice William Brennan memorably labeled in his dissent as a “fear of too much justice.” The Naruto concurrence suggests that granting animals Article III standing “would fundamentally alter the litigation landscape.” Attendant worries to this influx of cases are concerns about whether the animal interests expressed in a suit do indeed track the animals actual interests as well as concerns about whether animals will become pawns for other actors who are pursuing their own interests sotto voce.

These points are not to be taken lightly. Should animals be granted Article III standing, a whole host of procedural issues will need to be figured out, including, in addition to what the Ninth Circuit expressed, issues about jurisdiction and the distribution of potential damage awards. But these are surmountable obstacles, not absolute barriers that prevent recognizing what would otherwise be an appropriate legal posture. Indeed, there is no hard data about the possible influx of cases upon granting Article III standing to animals; it may very well be an overblown fear. Likewise, there are also common procedural devices that should minimize the threat of bad actors such as sanctions and frivolous litigation claims.

The second form concerns an animal’s appearance in the courtroom. As the Naruto concurrence intimates and as Matthew Armstrong argues baldly, “animals cannot walk into a courthouse and file a claim on their own” and therefore should not be afforded Article III standing. These kinds of arguments are just distractions, hand-waiving at a nebulous boogeyman and sidestepping the real issues. No advocate of standing for animals actually suggests that the animals must make an appearance in the courtroom to litigate their interests in their own names. (Nor indeed is presence in the courtroom necessary for such litigation.)

This kind of argument is more of a rhetorical tactic, designed to make the opposing positions seem fanciful and impractical. Indeed, this is the exact kind of argument that the Palila court, with its poetical description of a bird “wing[ing] its way into federal court as a plaintiff in its own right,” forces advocates for animal standing to endure. Even if the merits of the argument are specious, its rhetorical force certainly has a natural foothold in peoples’ minds. Advocates for Article III standing for animals already have an uphill battle. It becomes almost Sisyphean when opponents are able to easily distort the proposal.

III.  Same Goals, Different Strategy: Expanding the Scope of Justiciable Human Interests

It is in an effort to avoid those tired but effective rhetorical arguments that my proposal gains purchase. Recall that the two central goals of animal standing were the substantive goal of expanding animals’ legal protections as well as the symbolic goal of having animals as named plaintiffs. My proposal is that a more capacious approach to human injuries on behalf of animals—specifically a more capacious approach to “aesthetic injury”—is a plausible and legally justifiable avenue to pursue the substantive goal.

The symbolic goal of Article III standing for animals lacks a necessary connection to the substantive goal of greater legal protection. We should not be concerned about abandoning the symbolic goal because there are several nonlegal avenues through which it can come to fruition. Popularizing and disseminating leading scientific research on the lives of various animals—either in documentaries, in widely read newspapers and online forums, or in already existing animal sanctuaries and wildlife reservations—are all viable means of promoting the importance of and responsibility toward animals. When push comes to shove, parsimony and clarity must prevail. It is best to pursue the symbolic goal in a manner distinct from the substantive goal in order to maintain focus on the substantive goal.

The Supreme Court has recognized aesthetic injuries to satisfy the injury in fact element of Article III standing. In the animal law context, an aesthetic injury occurs when a human plaintiff’s sensibilities are injured by the mistreatment of an animal or the animal’s habitat. In delimiting the precise scope of this injury, the Court has instituted a proximity requirement to ensure that plaintiff’s injury via the putatively mistreated animal is not too “abstract” but rather “actual or imminent.”

As an illustration of this idea, consider the facts of Lujan v. Defenders of Wildlife (1992). Plaintiffs claimed aesthetic injuries at the mistreatment of nile crocodiles in Egypt as well as Asian elephants and leopards in Sri Lanka. The aesthetic injuries were that each plaintiff planned to return to those areas to enjoy observing the animals, and developmental projects in both areas threatened their ability to do so. This injury, the Court admitted, counts as an aesthetic injury. Yet the Court ruled that plaintiffs’ injuries were not “imminent” because, although each plaintiff professed an intention to return to these areas, they had no concrete evidence to corroborate their intent (such as plane tickets to visit Egypt or Sri Lanka).

The proximity requirement of aesthetic injuries aims to accomplish two things. It sets a practical limit on which humans can bring lawsuits on behalf of animals so as not to overburden courts, and it disincentivizes frivolous lawsuits. But the underlying justification of the proximity requirement—that proximity is a proxy for one’s connection to the animal—is an antiquated one given our modern, technological world.

My proposal is to expand the meaning of aesthetic injury to include virtual observers of animals, thereby doing away with the unnecessary proximity requirement.7How will this proposal come about? It is well within a judge’s common law powers to endorse this interpretation should the appropriate case arise. Congress could also pass legislation that explicitly endorses the expansive interpretation as a viable reading. (Alternatively, one could expand the meaning of “proximate” to include virtual proximity; either analysis will lead to the same place.)

Several wildlife exhibits and sanctuaries host livestream videos of various animals, where viewers can enjoy observing these animals without being physically proximate. A daily viewer of the Homosassa Springs Manatees can suffer an aesthetic injury at the manatee’s mistreatment or the destruction of the manatee’s habitat, even if the viewer lives thousands of miles away from the animal. The same, moreover, can be true of hundreds of wild animals, including bald eagles in California, grey seals off the English coast, gorillas in the forests of the Democratic Republic of Congo, and the list goes on and on.

What’s more, watching these animals virtually can likely establish a digital trail capable of performing the gate-keeping functions that the elements of aesthetic injury typically involve. Investigating the history of an IP address, for instance, can show whether an individual who claims an aesthetic injury on the basis of virtually observing a mistreated animal has indeed observed the animal with the frequency and duration necessary to satisfy the “actual or imminent” prong of injury in fact. There are surely manifold technological issues that will arise in developing this idea further, but addressing these are not necessary to see the conceptual promise of the idea.

Let us reimagine the facts of Defenders of Wildlife. Suppose that the plaintiffs did not travel to Egypt or Sri Lanka to observe the crocodiles, elephants, or leopards, but rather observed these animals virtually (and ample digital evidence confirms this). Under these facts, a court can plausibly find that the time and attention the plaintiffs invested in observing the animals shows that they are not bad-faith litigants and that the enjoyment they receive in observing these animals, if legitimately threatened, is a cognizable injury that courts can redress.

The principal benefit of this expanded scope is that it can achieve the substantive goal that advocates of Article III standing for animals seek: greater legal protection for the sundry interests of animals. Since animals are readily observable in the wild and divorced from immediate human presence, enjoyment from observing these animals—assuming the filming is unintrusive—does not prevent expression of how those animals live their characteristic lives and therefore the kinds of interests they may possess. In other words, a capacious approach to aesthetic injury can allow more interests of animals to be included.

Moreover, this novel approach to aesthetic injury can include animal interests in a nonreductive fashion. That humans may sue on the basis of their enjoyment in observing animals does not mean that only the direct elements of that enjoyment are justiciable. Basically, the capacious approach to aesthetic injury allows any factor that affects one’s enjoyment of observing an animal—ranging from extreme examples like the active hunting of the animal to more subtle ones like depriving the animal of a necessary food source—to be litigated in the courts. When I observe beavers, for example, the trapping of beavers could constitute an aesthetic injury, but so too, under the right conditions, could the eradication of trees out of which the beaver needs to build its dam. If the enjoyment of observing an animal presupposes that the animal has in place conditions necessary for it to live its characteristic life, then human-caused damages to those conditions may fall under the auspices of an aesthetic injury.


In the broadest terms, my solution to the entrenched stalemate concerning the pursuit of Article III standing for animals requires us to disentangle the goals of this pursuit from the strategy. Three things follow from doing so.

First, we are able to reevaluate with fresh eyes how the goals of Article III standing interrelate. Along these lines, I have argued that the substantive goal of achieving greater legal protection for animal interests takes priority over the symbolic goal, which can be easily achieved through other means.

Second, we are able to sidestep the traditional arguments against Article III standing. The idea of using a capacious approach to aesthetic injury avoids the traditional arguments against granting standing to animals. Although I find that these arguments on the whole are uncompelling, one need not share that finding to endorse a strategy that eschews confronting those arguments head on. Relatedly, my approach is also much less susceptible to the intellectually uncharitable but rhetorically effective characterizations that continue to haunt animal welfare advocates in the courtroom.

Third, reviewing the justifications behind the original limitations on aesthetic injury—such as the proximity requirement—shows them to be outdated. Our modern world has made aesthetic enjoyment and, correspondingly, aesthetic injury possible without being physically proximate to an animal. Moreover, a change that does away with this relic of a requirement allows humans to pursue legal remedies for the legitimate and cognizable interests of animals when those interests are unjustly burdened. Ultimately, if the goal of pursuing Article III standing for animals really is about increasing the legal protections afforded to animals’ manifold interests, I propose that those who care about this project turn their attention toward promoting an expansive interpretation of aesthetic injury and put Article III standing for animals aside.

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Tony Leyh is an Articles Editor of The University of Chicago Law Review and a J.D. Candidate in the University of Chicago Law School Class of 2022. He received his B.A. from Eckerd College in 2013 and his Ph.D. from Emory University in 2020.

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Featured Image: Sandra Strait, Celebes Crested Macaque-Postcards for the Lunch Bag.

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