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The Case for Non-Human Legal Personhood

Can non-human animals be granted legal standing?


Since Roman times, nonhuman animals have been considered property. This means that nonhumans have no legal standing and no voice in the legal system. Whilst there have been significant reforms over the last two centuries, including introducing animal welfare legislation, this does not go far enough to recognise the rights of nonhumans. Non-Human Rights Project on Behalf of Tommy v Lavery (‘Lavery’) and Non-Human Rights Project on Behalf of Hercules and Leo v Stony Brook University et al (‘SBU’) constituted an attempt by the Non-Human Rights Project (‘NHRP’) to have chimpanzees recognised as legal persons for the writ of habeas corpus. Whilst the NHRP was unsuccessful, the SBU judgment adopted a view of legal personhood capable of extension to nonhumans.


Habeas corpus is a common law writ that allows a ‘person’ to challenge their unlawful imprisonment. The NHRP brought Lavery and SBU on behalf of chimpanzees who were being held privately and at a university, respectively. The NHRP argued that chimpanzees had characteristics of autonomy and self-awareness, like humans, and so were deserving of equality and liberty. In Lavery, Peters PJ struck down any possibility of extending legal personhood.

In SBU, Jaffe J ultimately found herself bound by Lavery; however, the judgment indicated a contrasting interpretation of legal personhood and its potential for extension. Jaffe J acknowledged that legal personhood is subject to development, and not merely confined to human beings. It is not simply a matter of biology; rather, it is a question of ‘who counts under our law’. Noting the growing trend to avoid strict characterisation of nonhumans as property, Jaffe J implied that decisions of legal personhood should be contextual and seemed open to extending legal personhood based on nonhumans’ capacities.


Legal Personhood Exists on a Spectrum

Key to understanding the expansion of legal personhood is recognition that legal personhood is not binary but occurs on a range. Just as rationality and autonomy ‘fall on a continuum’, so does legal personhood, which flows from these characteristics. As discussed below, legal personhood does not come accompanied with a plethora of rights and responsibilities; rather, it is the capacity to hold a legal right, the content of which varies depending on context.

Characteristics of Nonhumans

The core reason for extending legal personhood to nonhumans is that they possess characteristics sufficient to hold legal rights. Research demonstrates that chimpanzees – the subject of Lavery and SBU – possess complex communicative and cognitive functions. In light of this, the basis of nonhumans’ claim to legal personhood — and humans’ current assignment of legal personhood — is practical autonomy, whereby nonhumans have interests that they pursue. In chimpanzees, this level of practical autonomy is comparable to humans’ practical autonomy. As such, this gives rise to the principle of equality: similarity in practical autonomy requires that they should be afforded the same access to legal personhood. Looking to research into nonhumans’ sentience and mental processes, it becomes evident that some nonhumans have exceptional capacities. Any distinction to humans, on such a basic level, is arbitrary. Nonhumans therefore deserve respect, dignity, and accompanying rights. To be effective, this must come in the form of legal personhood.

Advantages of a Rights-Based Approach

Legal personhood is preferable over conventional legislative methods of protection due to the ineffectiveness of the current legal framework around nonhumans, which is based on a welfarist approach. This approach states broadly that humans can use nonhumans providing that this is done humanely. The welfarist approach is not based on respect for nonhumans as individuals but is again anthropocentric and focuses on human concerns.

Conversely, rights-based protections focus on the equality and inherent worth of nonhumans and are a strong basis for protection. Expanding legal personhood would make the process of bringing actions regarding nonhumans more direct. This is because legal personhood would grant nonhumans standing and is likely to bring greater flexibility to the allocation of rights and duties in the case of humans and nonhumans. Moreover, opening the door for legal personhood for some nonhumans allows an incremental approach based on the context of each individual case, allowing the property status of nonhumans to be slowly dismantled.


There are some common objections to recognising legal personhood in nonhumans; however, as discussed below, these can be rejected.

Duties as a Feature of Personhood

As in Lavery, an objection to extending legal personhood is that nonhumans (unlike humans and other legal persons such as corporations) cannot fulfil duties – which are a fundamental element of legal personhood. Upholding duties requires a sense of rationality and morality, which nonhumans do not appear to possess. However, these attributes are not prerequisites to the assignment of rights: the question is whether legal personhood can exist without duties attached. The law already allows for some humans who are not required to uphold certain duties—but are still legal persons—due to incapacities, such as youth. Their legal personhood is flexible and contextual, as it would be for nonhumans. Thus, distinguishing between humans and nonhumans on this basis is arbitrary.

Dangerous Consequences

Some opponents argue that humans will be harmed by the recognition of legal personhood in nonhumans. This is based on the idea that expanded legal personhood would lower its value. However, extension of this principle does not mean that the basis for granting legal personhood to nonhumans (such as practical autonomy) would become the single definition of legal personhood. This is merely a ‘sufficient, not a necessary’ characteristic to acquire legal personhood, and, as discussed above, there would be different scales of legal personhood. Some argue that extending legal personhood could erode human equality, as many different beings would have scaled legal personhood. However, diversity within the human community is what gave rise to the idea of equality: it is illogical to suggest that increasing such diversity would endanger this principle.

Some contend that a finding of legal personhood will soon result in any nonhuman being granted the full array of human rights. Firstly, relying on Steven Wise’s account, only nonhumans displaying practical autonomy would be entitled to legal personhood. Secondly, the assignment of legal rights exists on a continuum, as does legal personhood. Recognising chimpanzees’ or other nonhumans’ legal personhood does not mean that they will be granted every possibly associated right. Rights would be assigned on a case-by-case basis, considering the nonhuman involved, their degree of practical autonomy, and their other capabilities. This is analogous to humans who are legal persons but do not possess the full myriad of rights, such as young children. Therefore, expanding legal personhood to nonhumans will not cause the radical and absurd results to which opponents allude.

Legal personhood for nonhumans is a logical step in recognising nonhumans’ innate capacities and interests. The courts are reluctant to affect this seemingly radical change, often rooted in a lack of prior recognition of nonhumans’ status. Yet, if this continues, and all ‘rights were defined by who exercised them in the past’, historical injustices would amount to ‘continued justification’. The SBU judgment shows promising willingness to consider the extension of legal personhood to nonhumans and conceptualises legal personhood in an expansive and non-binary manner. Ultimately, this approach of recognising the inherent moral worth of nonhumans, should be lauded.

Image: Rob Schreckhise

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