Sentient dignity and the plausible inclusion of animals

Abstract

Dignity often serves as the cornerstone for a justification of rights. However, it has been criticised for its exclusion of nonhuman animals and many human individuals: dignity is traditionally grounded in a capacity that some but not all humans and animals possess, e.g. rationality. To successfully overcome this problem of exclusion, this article argues that we should adopt an account of sentient dignity, i.e. an account of dignity based on sentience alone. The article thus makes three contributions. First, it demonstrates that the basis of dignity has yet to receive a plausible justification. To illustrate this, it outlines the problem of exclusion, and it exposes three problems with a prominent solution offered by Pablo Gilabert. According to Gilabert's view, dignity should be based on several valuable capacities including rationality, sentience and cooperation, among others. However, basing dignity on several capacities (i) risks over-inflating the scope of dignity, (ii) struggles to account for internal complexity, and (iii) produces problematic moral distinctions. Second, the article argues that sentient dignity overcomes these three problems whilst being plausibly inclusive. Finally, it contends that an account of sentient dignity vindicates the non-redundancy of dignity, renders sociopolitical discourse philosophically coherent, and harnesses dignity's potential strategic value.

Introduction

Dignity is a status that an individual possesses by virtue of having inherent worth. If a being has this status, they possess moral rights. However, dignity has come under fire recently for its purported exclusion of nonhuman animals (hereon: ‘animals’), and many human individuals such as infants and people with severe cognitive impairments (Challenger, 2023; Ebert, 2020; Kymlicka, 2018; Perry, 2023a; Rachels, 1990: chap. 2). This is because dignity is traditionally grounded in a single capacity that most but not all humans and only some animals possess, such as rationality (Christiano, 2008; Griffin, 2008; Kant, 1785/1997; Kateb, 2011). This is not only inconsistent with a presumed commitment to upholding the rights of all humans, but it also undermines the rights of animals.

This article argues that to successfully overcome this problem of exclusion we should adopt an account of sentient dignity, i.e. an account of dignity based on sentience alone, where sentience is understood as the capacity for subjective experiences. Although the notion that animals possess dignity is receiving increased philosophical, ¹ legal, ² and public attention, ³ few theorists have explicitly argued that sentience should be its fundamental basis, ⁴ and many do not directly defend an account of its basis at all. ⁵ This is despite the fact that the capacity for sentience is often understood as a morally relevant capacity, used as the justification for extending a wide number of ethical considerations to animals (Bentham, 1781/2000; Perry, 2024; Rachels, 1990; Regan, 1983; Singer, 1993). ⁶

Grounding dignity in sentience alone means eschewing its traditional basis in rationality, or another uniquely human capacity (Christiano, 2008; Griffin, 2008; Kateb, 2011). Some thinkers may worry that this undermines dignity. However, an account of sentient dignity is not only the most plausible way to overcome the problem of exclusion, but it also maintains the distinct benefits that come with adopting a dignitarian approach, namely, it vindicates the unique normative functions of dignity, renders sociopolitical discourse philosophically coherent, and harnesses dignity's strategic benefits.

To demonstrate this, the article examines one prominent pluralist solution to the problem of exclusion, defended by Pablo Gilabert (2018, 2023, 2024). ⁷ To include all humans and most if not all animals, Gilabert extends the number of valuable capacities at the basis of dignity beyond rationality to include empathy, cooperation, aesthetic appreciation, and even sentience, among others. ⁸ While Gilabert's account has many independent merits, it faces at least three problems in virtue of its pluralism:

it risks over-inflating the scope of dignity, since several entities other than humans and animals (such as plants and super-computers) may be counterintuitively included as bearers;

it creates intractable complexity when comparing the weight of dignity-based rights, because there are several fundamental grounds for those rights; and

it introduces problematic moral distinctions between different bearers of dignity, because not all dignity-bearers possess all the valuable capacities at the basis of dignity.

In contrast, an account of sentient dignity – that is, one which is based solely on sentience – avoids all three of these problems. Since sentience is the capacity for subjective experiences, and since humans and many, if not all, animals have subjective experiences, an account of sentient dignity includes humans and many, if not all, animals. Furthermore, it can account for a variety of different capacities by interpreting their moral relevance and comparing their relative moral weight in terms of sentience. Finally, since sentient dignity is based on a single capacity, it does not introduce problematic moral distinctions: all dignity-bearers have the same kind of status.

The upshot is that to plausibly overcome the problem of exclusion, we ought to advocate for sentient dignity. As the article will show, an account of sentient dignity maintains coherence with standard views about what makes dignity a valuable and important approach to theorising about rights in the first place – including providing the ‘desirable depth and structural functions that are needed to frame human rights discourse’ (Gilabert, 2024: 29). In doing so, it ensures the non-redundancy of dignity (cf. Zuolo, 2016): dignity is a unique status that informs us who the relevant rights-bearers are, helps to make sense of why interests generate rights, and explains how they do so. As such, it is also the foundation for a holistic approach to addressing practical and theoretical normative issues, one which lends philosophical coherence to socio-political discourse about ‘human’ rights. Finally, by focusing on a valuable capacity we have in common with other bearers of dignity despite our differences, sentient dignity can bridge both cultural and species divides. It can therefore harness the potential strategic value of dignity, by breaking down objectionable human-animal distinctions and promoting animal rights.

The article proceeds in three steps. First, it outlines the concept of dignity and the problem of exclusion in greater detail, alongside an overview of how exactly Gilabert attempts to overcome this problem. Second, it exposes the three problems faced by a pluralist solution to the problem of exclusion and, in doing so, reveals how and why an account of dignity based on sentience alone can overcome these problems. Third, it argues that sentient dignity vindicates the unique philosophical and strategic value of dignity: in other words, sentient dignity can lead to the plausible inclusion of all sentient humans and animals within a dignity-based rights framework. The article concludes with some brief reflections on implications. Most notably, sentient dignity forms a stable and robust strategic platform for a broad coalition in support of human and animal rights.

The problem of exclusion

While several philosophers have pointed out the exclusionary nature of normative theory in general, ⁹ there are good reasons why an exclusionary worry especially applies to dignity. Most prominently, Kymlicka (2018) has argued that several theories of dignity imply human supremacism. According to these theories (whose contemporary champions include Kateb (2011) and Waldron (2012)), ‘a core component of human dignity is our radical difference from, and superiority over, animals’ (Kymlicka, 2018: 768).

To see why, we need a more specific understanding of dignity. While there are numerous definitions in the contemporary literature (Bird, 2021: chap. 4; Debes, 2009: 60; Etinson, 2020; Killmister, 2020; Waldron, 2012), this article focuses on dignity as a deontic, or rights-based status that signals its bearers’ inherent value and the existence of particularly robust, claimable, and universal duties towards them. ¹⁰ In this sense, dignity is a kind of moral status. ¹¹ While the notion of moral status captures a range of normative positions, reliance on the notion of dignity signifies commitment to a particular substantive account. The notion of dignity is an anchoring idea within a holistic conceptual network for approaching the theory and practice of ‘human’ rights. Three of the structural components of Gilabert's (2018: 122–131, 2023: 6–10, 2024: 29–33) account demonstrate the role of dignity in that network:

Status-dignity: A has the status of dignity if A possesses P, a morally valuable property or set of properties that are at the basis of dignity. If a being possesses P, they have inherent value, and so they have this status.

Dignity-based rights: There are certain rights, R, about how A ought to be treated that are responsive to P and justified with reference to P. ¹²

Condition-dignity: A experiences a condition of dignity if A's status-dignity is protected/respected, such that A is treated in accordance with R.

The problem of exclusion holds that theories of dignity tend to objectionably exclude animals, and they often also objectionably exclude many humans lacking certain capacities, such as rationality. This is because if an exclusionary property such as rationality grounds dignity, this implies that animals (and any humans that lack the relevant property) lack inherent value and so lack dignity. If this were true, it would also follow that animals (and some humans) lack rights. This conflicts with the recognition of animals as bearers of inherent worth, and supervening rights.

Kymlicka (2018) is not alone in advancing this objection. Rossello (2017a, 2017b) and Fasel (2019) argue that dignity is often understood as a form of speciesist ‘aristocracy’. This form of speciesism has its origins in an unjustified in-group/out-group ‘tribalism’ (Figdor, 2021; Jaquet, 2022). Given our shared similarity, drawing a line between humans and animals in this way is arbitrary (Ebert, 2020; Rachels, 1990). ¹³ Indeed, there may be no valuable capacity that can set humans apart from other animals, especially not in a way that meaningfully includes nearly all and only humans (Perry, 2023a). This arguably follows even if the relevant capacity is understood in modal terms (Gildea, 2024).

The problem of exclusion therefore has real force against traditional theories of dignity. Assuming that this challenge is correct, we should either reject dignity entirely in support of an alternative account of rights or develop an account of dignity and rights that includes all humans and most, if not all, animals.

This article opts for the second route. While there are several accounts of rights not based on dignity (e.g. (Cochrane, 2012; Donaldson and Kymlicka, 2013; Garner, 2013)), these lack the benefits that come with adopting a dignitarian approach (Gilabert, 2024: 27–29). Importantly, they lack the unique philosophical and strategic value of dignity, and so they are unable to make sense of, guide, and shape discourse surrounding dignity and human rights by providing it with explanatory depth and rendering it philosophically coherent. As the final part of this article argues in further depth, dignity avoids charges of redundancy even when extended to animals (cf. Bagaric and Allan, 2006; Macklin, 2003; Sangiovanni, 2017: chap. 1; Zuolo, 2016). For starters, dignity is a philosophically distinct concept that captures the unique status of its bearers (Bader, 2023; Zylberman, 2018), helping to ‘bridge’ the gap between interests and rights (Gilabert, 2018: 204–209, 2024: 27). Indeed, dignity is an anchoring idea that signals a holistic and structural approach to the theory and practice of ‘human’ rights (Gilabert, 2018: chap. 6). Second, dignity is relevant and necessary because of its potential strategic value. Using the word dignity adds ‘rhetorical flourish’ (DeGrazia, 1996: 67) to announcements or reminders of the rights-status of individuals and pulls on our psychological tendencies to favour in-group members. Indeed, the term has significance and weight in public discourse, and it is widely used in International Human Rights Law as an ‘interstitial’ concept that helps to bridge cultural differences (Riley, 2019). By conforming to contemporary usage, we increase the relevance of philosophical understandings of rights and can deploy dignity's potential strategic value in support of animals’ inclusion in social, political and legal contexts. Rather than rejecting dignity, we should rely on a more inclusive account that renders dignity more coherent and plausible: one that maintains the benefits above but does not focus on ‘humanity’ alone.

It is exactly such an account that Gilabert (2023: 4–14, 2024) has attempted to deliver. ¹⁴ Crucially, Gilabert (2018: 127, 2023: 8–9, 2024: 31) argues that we should be pluralists about the basis for status-dignity. Rather than eschewing rationality, Gilabert suggests that we should look beyond rationality and extend the list of valuable capacities that ground dignity to include creativity, sentience, empathy, cooperation, aesthetic appreciation, and a range of capacities for practical, technical and moral reasoning, among others. In Gilabert's view, possessing one of these valuable capacities is sufficient for the possession of status-dignity.

If successful, this pluralist move would overcome the problem of exclusion. All humans and animals traditionally excluded from possessing dignity can be included as bearers of dignity, assuming they have at least one of the valuable capacities at the basis. We (moral agents) have duties to treat them in line with moral rights that are responsive to those capacities. For instance, we should ensure they have time and opportunity to cooperate with one another. If we do so, then the individuals enjoy condition-dignity.

Three virtues of sentient dignity

Despite its appeal, a pluralist view about the basis of dignity faces three problems that an account based on sentience alone does not. Pluralism (i) over-inflates the scope of dignity; (ii) generates intractable if not unworkable complexity in the underlying capacities at the basis; and (iii) results in problematic moral distinctions between individuals who do and do not have certain valuable capacities. This section outlines these problems and argues that avoiding each of them is a virtue of an account of sentient dignity, that is, an account of dignity based on sentience alone.

Examining Gilabert's pluralist account helps us to see why the most plausible solution to the problem of exclusion is to ground dignity solely in sentience. However, Gilabert's view has several independent merits. While the arguments below critique it, they do not undermine the overall structure of his account. On the contrary, the article relies on the other components of Gilabert's view down the line.

To begin, a brief definition of sentience is needed. Sentience is the capacity for subjective experiences. While some accounts of sentience focus on pleasure and pain alone (Bentham, 1781/2000: Chap. 1), bearers of sentience – such as dogs, pigs, fish, birds and of course humans – experience a wide array of affective and evaluative states (Balcombe, 2009; Birch, 2024: chap. 2; Dawkins, 2006; DeGrazia, 1996). Sentience should therefore be understood as comprising the capacity to experience a range of modifiable mental states rather than solely pleasure and pain, such as contentment, boredom, grief, affection, and even simply the sensations in one's toes (Kagan, 2019: 13; Shepherd, 2018: 49–51). Several other theorists also adopt this more plausible and capacious understanding (DeGrazia, 1996; Kagan, 2019; Korsgaard, 2018; Regan, 1983). With this working definition in hand, let us turn to the three problems faced by pluralism.

Scope

The first problem concerns the scope of dignity. Gilabert offers a list of intuitively valuable capacities (sentience, self-awareness, empathy, cooperation, etc.) by surveying the world to ‘see what entities in it have valuable capacities giving rise to status-dignity’ (Gilabert, 2024: 33). While this is a plausible start, it is not the whole story. The second step in justifiably determining who is and is not a dignity-bearer requires us to examine which entities possess the valuable capacities we identify and to rule out many capacities as sufficient bases for dignity, especially if they result in incoherence down the line.

Depending on which capacities form the basis of dignity, a pluralist account can result in incoherence in the form of over-inflation. ¹⁵ Before explaining why, it is important to acknowledge that Gilabert recognises that the valuable capacities at the basis of dignity are an ‘initial list’ that we should see as ‘open to various forms of evidentiary support and epistemic improvement’ (Gilabert, 2023: 8–9). In other words, Gilabert expresses openness to his view being revised. With this in mind, recall that the guiding motivation behind the problem of exclusion is the moral undesirability of excluding animals and some humans from an account of dignity. However, we not only have convictions about who ought to be included, but about who ought to be excluded. Pluralism can result in a conflict with these intuitions. To see this, we need to run a simple test: if any given being only had one of the set of valuable capacities at the basis of a pluralist conception of dignity, and none of the others, then would we still want to conclude that they possess dignity? For example, it is conceivable that the supercomputer HAL from 2001: A Space Odyssey could engage in ‘technical, prudential and moral reasoning’ (Gilabert, 2023: 8), but supercomputers do not seem to be the kind of beings that strike us as possessing dignity. Since a being that can only engage in reasoning would lack their own ends (they would have none of their own interests), ¹⁶ they would not experience satisfaction when the things they reason towards are achieved, or obstructed. As such, it is not clear we could violate their rights. To be sure, this is a point that Gilabert also expresses concern for: he notes that ‘a capacity for theoretical knowledge might appear relevant only when associated with a capacity for qualitative experiences or for practical agency or striving’ (idem, 10; emphasis added). In other words, Gilabert appears to share the worry about over-inclusion, and that responding to this worry might require us to impose necessary limits on the possession of dignity.

For a different example, consider ‘cooperation’: many plants engage in cooperative ‘joint activities with others for common ends’ (idem: 8). For example, trees share nutrients through fungal networks. But plants do not tend to strike us as dignity-bearers. It seems implausible to think they have an inherent value that is independent of our valuing them (Mortto, 2003) – one which can ground a form of direct moral status such as dignity (Basl, 2019). Including plants as dignity-bearers would therefore be inapt, or even undermine the claim that sentient animals have dignity (Shaw et al., 2024: 3). Again, it may be that Gilabert's view can accommodate a critique of this sort if we adopt a more specific understanding of what counts as cooperation, e.g. Gilabert may have in mind cooperation involving intentional action for the benefit of sentient beings. As before, this points towards the idea that a capacity such as sentience might be necessary for dignity.

This might give rise to an immediate objection: even if we have intuitions that plants and supercomputers do not have dignity, many people also hold intuitions that cows, rats, and fish do not as well. Why should we give justificatory weight to some intuitions about who ought to be excluded from an account of dignity, and not others? To answer this question, an important clarification is needed. Reaching justificatory coherence is not about giving unexamined weight to beliefs we already have (Scanlon, 2003). Convictions about particular cases act as provisional judgement points for determining whether any particular conception of dignity is correct. If we have an intuition that some individual or entity does not have dignity, then we ought to investigate that intuition to see if there are any coherent and well-justified reasons for holding it. However, if we find that there are no such reasons, then we ought to reject that intuition. In other words, what counts as a good reason for giving an intuition justificatory weight is largely determined by wide reflective equilibrium with other principles and convictions (ibid). If someone holds the intuition that animals should be excluded from an account of dignity, then this intuition ought to be rejected because it follows from speciesist ideas as opposed to a well-considered theoretical position (as outlined in the previous section) (Horta, 2010; Jaquet, 2022). This is an instance in which a conviction ought to be revised if and because it is poorly justified and incoherent with other beliefs. In contrast, the intuition that we ought to exclude plants and supercomputers from an account of dignity can be coherently and plausibly justified.

To see this, consider the example of plants again. Imagine that someone has the intuition that ancient red cedars should be included as dignity-bearers. How should we explain this intuition? Perhaps in light of their age and magnitude, these entities may have significant moral and aesthetic value. But this does not coherently imply they have dignity for at least two reasons. First, extending dignity to these entities introduces more problems than it resolves. This includes the problems that will be explained below. But, as gestured at above, dignity is also an inapt notion to assign to non-sentient living beings because dignity is possessed solely by entities which have inherent value. Ancient red cedars may have immense instrumental or extrinsic value (and they may even hold this value as ends in themselves (McShane, 2007). However, this value is best explained by the fact that they are of value to sentient-beings (whether directly or indirectly) (Tenen, 2020, 2022), not as an inherent property. Second, a separate notion – that of indirect moral status – is sufficient to account for the weighty moral considerations we owe to them (Perry, 2024: 728; Tenen, 2020). According to this idea, the moral status of ancient red cedars derives from the value they have to sentient beings. It follows that we need not give justificatory weight to intuitions about excluding animals, even if we give weight to other intuitions about exclusion.

However, why should we think that including sentience as necessary for dignity will match our intuitions? We can be certain that an account based on sentience will include within the scope of dignity almost all humans as well as most, if not all, mammals and birds: the scientific consensus is that these animals are most probably sentient (Andrews et al., 2024; Birch, 2024: ch. 12). What's more, using sentience as a scope likely means including all other vertebrates at a minimum, including fish and reptiles (Birch, 2024: 236), as well as at least some invertebrates such as octopuses (idem: 237–240). These beings are likely to already strike us as plausible dignity-bearers. However, things become more nuanced when we turn again to our credible intuitions about exclusion.

A sentience-based approach very clearly rules out supercomputers and plants: few entertain the idea that supercomputers are currently sentient, ¹⁷ and the idea that plants are sentient has been debunked as a modern ‘myth’ (Mallatt et al., 2021) that ought not to be of precautionary concern (Birch, 2024: 281–283). ¹⁸ Nonetheless, there is still a large grey area between these cases, and the ‘clearest candidates’ of sentience, such as mammals (idem: chap. 12). This grey area includes invertebrates such as crabs, insects, and worms. The problem here is not only that we lack the evidence about which beings are sentient, but also that we lack confidence in our own evaluations (idem: 11). To grapple with this, Birch has proposed that we shift to the language of ‘candidature’ and away from any onus on certainty (idem: 233). This involves adopting a ‘theory light’ perspective, according to which we search for markers of sentience, instead of aiming to discover clear-cut evidence of it (Andrews, 2020; Birch, 2022). Rather than attempting to draw clear lines, we should embrace the reasonable zones of disagreement that this gives rise to, and develop precautionary policies and regulations (Birch, 2024: chaps. 4–6). For instance, consider insects. The consensus is that there is at least a ‘realistic possibility’ of conscious experience in some insects (Andrews et al., 2024). If true, it may be right to think of some insects as having a dignity. However, this implication need not lead to an objectionable conflict with our intuitions if we incorporate a sensitivity to this grey area into any practical, legal or public policy regulations. These should require us to be open to the latest research on which different beings are likely to be ‘sentience candidates’ (Birch, 2024: 1), thereby helping to determine more accurately which beings are bearers and non-bearers of dignity (Birch, 2022: 20, 2024). ¹⁹

Furthermore, regulations should be sensitive to the risk of over as well as under inclusion. In this sense, it is not only our intuitions that can sometimes be provisional: our evaluation of what counts as the kind of sentience that grounds dignity may need adjusting as we learn more. Reflective equilibrium is an iterative process. It allows us to embrace the ‘serious doubts’ that we start to feel when thinking about the dignity of some entities (one way or the other), such as bees or grasshoppers (Birch, 2024: 11). If including some entities is too counterintuitive, incoherent or implausible, we might make minor adjustments to our understanding of what degree or kind of sentience grounds dignity. As mentioned, the uncertainty here speaks against sharp lines. Much like Gilabert notes about his own account, the basis of sentient dignity should also be ‘open to… epistemic improvement’ (Gilabert, 2023: 8–9). An account of sentient dignity can capture this: it unequivocally includes the clearest candidates while integrating sensitivity to those at the margins. Adopting sentience as the sole basis for dignity therefore allows us to ensure adequate inclusion while implementing the best approach to avoiding counterintuitive overinflation.

One final thought may be that not all valuable capacities at the basis of a pluralist account of dignity will result in over-inflation, for instance, if only bearers of sentience possess those capacities in any case. While this is true, it is not clear why such capacities must then play a role in grounding dignity. If basing dignity in sentience already determines the scope of dignity, then including additional capacities will be redundant, and, as we will see below, it produces additional problems for theorising about dignity and rights. In contrast, if it is sentience alone which is at the heart of what it means to possess dignity, then we can overcome the problem of exclusion while easily avoiding overinflation.

Complexity

The second problem is that pluralism cannot straightforwardly account for internal complexity without running into challenging questions about how to weigh up different capacities at the basis of dignity. As Gilabert notes, dignity-based rights must account for ‘complex connections’ between different capacities an individual might have (Gilabert, 2024: 31). To achieve this, Gilabert stipulates that some capacities ‘may well constrain other capacities’ when we specify the rights individuals have (ibid). This targets an important consideration about balancing competing interests. For instance, we should not always impose decisions that would be (objectively) good for someone's capacities in one respect (e.g. because it increases opportunities for cooperation), since this may fail to be responsive to their capacities in another respect (e.g. because it disregards their rational choices). Accommodating this seems necessary for an account of dignity to be plausible.

However, comparisons require a standard against which we can determine which option wins out. For instance, if you are deciding whether to admit person A or person B into a university you could use their grades as a basis for comparison. In contrast, if we face a conflict over whether to promote or protect one valuable capacity or another on a pluralist account of the basis of dignity, it is not clear what metric we should use to make this decision, precisely because the basis for dignity is morally fundamental in determining rights in the first place. Recall that this is because dignity-based rights are responsive to the basis of dignity. Hence, a challenge of incommensurability arises. For instance, if we must decide whether to prioritise a responsiveness to your capacity for empathy or to your capacity for rationality, then in any given context we have no means to work out which one should win out because both are morally fundamental.

These questions might be answered with further principles that assign different weights to the capacities at the basis of dignity. However, we do not face these problems in the first place on the sentient dignity account because an individual's sentience (in other words, their experiences of subjective mental states) forms the background against which we can make comparisons.

The basis of dignity (in this case, sentience) is what rights are responsive to. To account for the complexity in the rights individuals have, we should understand the value of the various capacities individuals possess via their sentience (Perry, 2024): for instance, you have a right to have your agency respected because your agency is valuable in virtue of you having positive subjective experiences when your agency is respected, e.g. because you appreciate what your agency can do for you. Because of this, we can compare which rights of an individual should take priority by comparing whether to prioritise one capacity or another with reference to those capacities’ sentience-based value. For instance, if we prioritise your capacity for agency over your capacity for aesthetic appreciation, we should do so because prioritising your agency is more valuable according to your subjective experiences about the (potential or actual) value of these capacities. Similarly, a dog's interest in smelling generates rights regarding their olfactory capacity because their olfactory capacity is valuable with reference to this capacity's (direct or indirect) impact on their sentience. We may sometimes prioritise their olfactory capacity over their capacity to play because sniffing things is more valuable to the dog in that moment.

Notice that claiming this does not require us to claim that a sentient being's other capacities lack value. ²⁰ Instead, the point is that their value should be thought of as depending on and deriving from their capacity for sentience. This is crucial because it allows us to account for a range of important moral considerations. For instance, consider agency once more. Ideally, an account of sentient dignity ought to be able to make sense of why agency has value. Consider an example in which sentience appears to have little direct importance. Imagine that person A is locked in a room against their will and person B is free to go where they want, but both have equal welfare (e.g. perhaps because A is currently unaware they are trapped). B's situation seems normatively preferably to A's, but this appears to be solely due to difference in their agential options. In this case, the most morally important factor is clearly freedom, but the reason why this factor is morally important can still be explained with reference to sentience. Freedom is valuable to sentient individuals who have the capacity for agency. This may be for prudential reasons, for instance, if A wanted to leave the room to pursue other things they value, they would not be able to. B's options are wider, and having more options is generally an instrumentally good thing because having options is in our interest. However, a focus on sentience can also explain why our capacities for agency may be valuable for their own sake, too, even if this follows for reasons that derive from sentience (Perry, 2024: 730–732). The idea here is that we might prefer B's situation to A's even if there is not instrumental benefit to B. For instance, it may be that ‘we appreciate the range of options this makes available’ irrespective of whether we pursue those options (ibid). Despite this, the value of this capacity still derives from the fact that we are sentient beings: it is because we have subjective experiences of valuing our agency that our agency is of value to us. It follows that even if sentience is not obviously the most morally important factor in any given context, it can still explain why other factors are morally important.

One of the virtues of this way of approaching internal complexity is that it has considerable explanatory power across species differences (ibid). ²¹ Consider fireworks that emit a loud bang. These impose a significant harm on other animals (Bateman et al., 2023). A focus on sentience allows us to explain the magnitude and wider impact of this on animals’ other experiences. For instance, it may be precisely because many of these animals have much more sensitive hearing than humans that the harm should be considered a dignity-based rights-violation. What's more, loud fireworks may have a damaging effect on a pet's fear response down the line independent of the initial harm it might cause them (idem: 397). Similarly, fireworks can negatively affect migratory and reproductive behaviours of wild birds (ibid). Centring sentience illuminates and helps us to understand these various wrongs.

However, a sentience-based theory may be vulnerable to a similar problem to pluralism concerning internal complexity about dignity's basis. This is because sentience in fact captures a range of smaller capacities – e.g. to feel one's toes being tickled, to experience a persistent ache in one's back, or to experience love and heartache. There are a considerable number, kind, and intensity of various subjective experiences. The thought may therefore be that we have simply passed the buck onto the different dimensions of sentience: if the problem for pluralism was its inability to compare the relative weight of different capacities at the basis, does this problem also arise for comparisons of the various dimensions of sentience?

A sentience-based view clearly faces challenging questions here. But these do not undermine a theory based on sentience because sentience should be thought of as a single, unified capacity, even if it is made up of several constituent dimensions that vary in intensity, duration, propinquity, fecundity, purity, and so on (Bentham, 1781/2000). Although different subjective experiences may vary widely, these experiences share an objective structure, one which plausibly remains the same for all sentient beings (Lee, 2023: 560–563, 2024). This follows even if unanswered questions remain about what a particular being's subjective experiences are like, e.g. what it is exactly like for a bat to be a bat (Birch, 2024: 56; Nagel, 1974). Consider an analogy with size (Lee, 2023: 560): an object's size is multi-dimensional because it is made up of its width, length and depth, but this nonetheless makes size a unique characteristic of an object. The same is true of sentience. We observe that a particular being has sentience by looking for certain markers of sentience that are made up of their more discrete capacities – such as the functioning of their nervous system, their cognition, and certain behavioural characteristics. We infer based on this that a particular being has a wider capacity for sentience as a whole, because this evidence points to the idea that their experiences are structured in terms of unified evaluative and affective characteristics (Lee, 2024; Shepherd, 2018: chap. 6). For instance, we might observe that some object produces positive/negatives affects in the nervous system, which the being responds to. We can infer from the activities they engage in what the ends they are striving towards are. We can read their body language and the messages they are communicating to us and to one another about their mental states. In other words, we can understand the ‘evaluative phenomenal character’ of their experience (Shepherd, 2018: 38) – the sense in which the world has a unified structure for them in terms of certain things as to-be-sought and to-be-avoided.

Because of this general structure, sentience is meaningfully thought of as a single capacity that can be used as a common basis for internal comparisons and assessments of how to treat a sentient being, even if those sentient experiences vary because each of them can be thought of as making sense of the same thing: a being's subjective experience of the world. This by no means implies that all substantive problems of how to compare and prioritise different experiences and their impact on an individual's welfare are resolved (Lee, Forthcoming). However, it does mean that we avoid incommensurability difficulties because the discrete capacities we compare when we assess a sentient being's experiences are part of the same capacity.

Notice that a similar response is not available to the pluralist. This is because a pluralist cannot simply explain that we ought to focus on the way a particular capacity orders how we should understand other capacities without their view collapsing into some kind of monism. The problem of complexity arises for the pluralist because internal comparisons require a basis. There must be something in terms of which we should assess the relative weight we should assign an individual's different capacities. From a pluralist view, we lack this precisely because each capacity is thought to be morally fundamental. The moment one capacity orders and determines the moral importance of another, it is that capacity which is the fundamental basis of our moral assessment. And it is exactly this that makes an account of sentient dignity convincing: we can account for complexity because our other capacities are morally valuable in virtue of our sentience being morally valuable. Any problems that might arise in accounting for complexity are therefore avoided because sentience is the sole basis for dignity, and so it forms the background against which we assess and compare the value of other capacities. To be sure, this leaves certain questions open. But adopting sentient dignity provides the resources to answer those questions.

Moral distinctions

The final problem concerns the problematic moral distinctions that a pluralist account of dignity introduces, for instance, between animals that can and cannot cooperate with one another, or humans that possess complex rationality and humans that do not. Gilabert is aware of concerns of this sort. He states that ‘the dignity of the human individual involves a greater array of valuable capacities that call for greater regard’, but he also expresses the intuition that dignity should not be used to ‘quantify how much… [different dignity-bearers] count by comparison with one another’ (Gilabert, 2024: 37–38). While there is some tension here, Gilabert is optimistic that the dignitarian approach can be ‘fruitful’ in resolving this (idem: 38).

The dignitarian approach does have the resources to address this tension – but only if a sentience-only view of dignity is adopted. In contrast, a pluralist account introduces distinctions between animals that possess some of the valuable capacities at the basis for dignity and not others. This follows because several valuable capacities are used as the basis for different rights. ²² As such, those capacities take on a morally fundamental role in our reasoning about how to treat one another. This is what leads Gilabert (idem: 37–38) to conclude that a greater number of valuable capacities should lead to a higher degree or type of consideration, e.g. for persons as opposed to animals: if you have a valuable capacity that an animal does not, then there are further and fundamentally distinct ways in which we should morally consider you, according to pluralism. ²³

If several valuable capacities are at the basis for dignity, then moral distinctions will be pervasive, but perhaps the most troubling will be between different individuals of the same species: consider, for instance, humans who lack rationality, or developed capacities for empathy. If valuable capacities can be used to distinguish between humans and animals, then consistency would require us to also use them to distinguish between humans. But, to many, this seems highly objectionable. Indeed, it runs against the direction of contemporary thinking over human rights and dignity. As will be discussed below, such thinking emphasises unity in virtue of what we have in common. While a pluralist account will not argue that humans lacking a particular valuable capacity lack dignity, it would (on this rendering) seem to introduce problematic ranks between dignity bearers that could entrench already existing inequalities, for instance, between individuals who do and do not have certain cognitive impairments. Gilabert, (2024: 37–38) suggests we could avoid these implications by adopting a threshold above which individuals should be considered equal, and that such an approach could include people with cognitive disabilities. Yet, objections about the arbitrariness of the threshold then arise (Floris, 2023: 227–229): what would justify imposing the threshold in such a way that includes all humans (and some nonhuman animals) while excluding most other animals? Indeed, this move simply reinvites the problem of exclusion: while animals below the threshold would possess dignity on such a view, they would not possess the same dignity as other animals. As such, while the problem is no longer that animals are entirely excluded, there is still an exclusionary complaint. The dignity possessed by those surpassing the threshold is defended ‘on the backs of’ those that are excluded (Kymlicka, 2018: 770).

In contrast, a purely sentience-based account of dignity will not face these problems, because it is sentience alone that we must be responsive to when respecting others’ rights. As discussed, this can still allow us to make sense of the value of different capacities different beings might possess (including agency). This is because the capacities that, on pluralism, are used to fundamentally distinguish between bearers of dignity are still morally relevant. However, on a sentience-only view their relevance depends on and is understood in terms of sentience. As such, an account of sentient dignity does not lead us to the objectionable conclusion that some possess a distinguishable kind of dignity to others. Instead, all dignity-bearers possess dignity in virtue of possessing the same valuable capacity and so they have the same kind of dignity: one being's dignity is symmetrical to another's (Korsgaard, 2018: chap. 4; Zylberman, 2018: 746).

Yet, if all sentient beings have a symmetrical dignity, does this mean that all sentient beings possess the exact same rights and that those rights have equal force? For instance, would octopuses have the same rights as humans? A dignitarian approach has the resources to answer questions of this sort. We can do so by distinguishing between fundamental and derivative rights (Cochrane, 2013: 666; Schaefer, 2005). In a sense, sentient beings do possess the same fundamental right(s). A right of this sort is responsive to the capacity at the basis of dignity (sentience) and possessed symmetrically among all dignity-bearers. In contrast, sentient beings possess a diverse number and range of derivative rights. Derivative rights are specific and contextual versions of the fundamental right(s) and must be satisfied because they contribute to the satisfaction of the fundamental right(s). Claiming that humans have a right to education does not therefore require claiming that octopuses also possess that right, even if humans’ right to education is grounded in the same fundamental right that octopuses possess (e.g. to developing one's capacities) (Stucki, 2023: 95–99). What's more, other animals may have unique dignity-based rights that humans lack (ibid). Indeed, it may be plausible to develop species-specific sets of legal rights, philosophically grounded in sentient dignity, that help make sense of variations (Fasel, 2024: chap. 7).

It may be objected that while there may not be different kinds of dignity, there could still be different degrees. ²⁴ Since sentience can plausibly vary in degree (Lee, 2023), dignity could vary in degree by tracking this variation, too. This would result in a hierarchical account of dignity. A version of this view is defended in the case of moral status by Kagan (2019). If animals are included as bearers of dignity, this hierarchical view might be an attractive proposal, given challenging questions about how we should approach decisions over whether to prioritise a human's or another animal's interests. For instance, which sentient beings should we save in tragic rescue cases? A hierarchical view provides a straightforward answer: we should favour humans because they have a higher status. Yet, this is concerning from a dignitarian point of view because dignity-bearers are often thought of as ‘one another's equals’ (Waldron, 2017). A few points in support of a non-hierarchical account are worth noting, ²⁵ although these will fall short of a fully-fledged position in this debate.

First, a hierarchical account is not straightforwardly implied by the nature of the property that grounds dignity. If sentience varies in degrees, then this does not necessitate variations in dignity (Miklosi, 2022: 374–380). The relevance of the mere possession of sentience and the relevance of how much sentience one has are two separate things. If sentience is fundamentally morally relevant for a being's possession of dignity, this does not necessarily imply that how much sentience a being possesses is also relevant. The reverse is also true: if sentience did not vary in degrees then this would not necessitate equality. This is because ‘every kind of egalitarianism has the responsibility of saying why all subjects are to be treated as having equal worth’ (Debes, 2009: 59). So, the relevance and scope of moral equality must be established, and this follows for any account of dignity based on natural properties (Sangiovanni, 2017: chap. 1).

Second, conflicts between rights can be addressed without resorting to the claim that dignity should come in degrees because variations in different beings’ interests can be incorporated into the derivative rights they possess. Imagine for illustrative purposes that one fundamental right is the right to life (Cochrane, 2018: 28). Further, imagine that two beings – a dog and a human – both require rescuing in a wildfire. Is it the dog or the human who has the derivative right to rescue? A hierarchical view will claim that the human has a more stringent fundamental right to life, and so all things considered will have the derivative right to rescue. While this is the intuitively correct outcome, we need not claim that the human has a more stringent fundamental right to arrive at it. Instead, we can reach it by simply specifying the content of what the fundamental right to life requires, even if we hold that both the dog's and the human's rights are equally stringent (Zylberman, 2022: 556–561).

The content of a fundamental right should be specified by two things: the interests at stake, and the particular contexts in which those interests are threatened. For now, let us put the contexts to one side (these will be addressed below) and focus just on the interests. Although different beings’ interests will vary widely depending on the kind and degree of sentience they possess, all dignity-bearers have sentience. So, as we saw above, we have a stable basis to both determine and compare these interests. To do so, we should work out which interests the being has at stake and try to determine the relative disadvantage each being faces to pursuing those interests. The relative disadvantage is determined by the amount that each being's interests will be set back. In other words, which being has the most to lose from not having their fundamental right to life satisfied? In many cases, answering this question may involve claiming that the human has a derivative right to rescue because they will face a greater relative disadvantage than the dog, precisely because they have weightier interests in continued existence (McMahan, 2002: 195–199; Singer, 1975: chap. 1). This weightier interest might derive from their more extensive life plans, for example (ibid). Importantly, though, this does not mean that the dog's fundamental right to life has less absolute stringency. Instead, the conclusion follows merely from differences in the relative interests at stake. Indeed, this reflects the idea that equal consideration need not require equal treatment (Cochrane, 2013: 669–671; Singer, 1993: 58–61): in fact, equal consideration often requires us to give differential treatment when some individuals face a greater relative disadvantage in achieving their interests than others (McMahan, 2002: 195–199).

Consider how this approach would address the possibility (mentioned in the discussion of scope above) that an account of sentient dignity might include insects. If some insects were to possess a relevant capacity for sentience, for instance, then they may have dignity. However, this would not translate into identical treatment between insects and other sentient beings, even if it were to require that we more widely consider our treatment of insects. Our moral obligations to sentient beings vary based on their specific sentience-based interests, and the relative disadvantages they face. If insects are sentient, they most probably do not experience suffering in the same way as other animals (Birch, 2024: chap. 14), meaning their moral inclusion would not be too demanding. The framework for addressing conflicts proposed here allows for varying obligations based on the level of disadvantage an individual faces in relation to their sentience-based interests.

Finally, contextual and relational factors are important (Aaltola, 2005; Palmer, 2010). There are several reasons why an account of dignity should be sensitive to these and might mean that we are sometimes required to favour other animals over humans. First, our assessment of which interests should take priority can vary widely based on contextual factors. There are likely cases in which some animals, particularly those with well-developed capacities for prudential reasoning, have a deeper interest in continued existence than some humans, such as elephants or dolphins. Second, relative disadvantage in other areas should play a role in our considerations. For instance, it may be that we ought to save a young farm animal who has grown up on an industrial farm over an elderly person who has lived a long life. When comparing the relative disadvantage and success that each of these dignity-bearers have in leading a life that is of value to them, we can see that the farm animals will have experienced greater deprivation and obstruction to their interests. Third, we ought to be careful of the weight we give to intuitions in support of humans, especially given psychological tendencies and the possible social and legal consequences of not saving humans. Finally, relationships with and between humans and animals significantly impact our moral evaluations. Our previous relationships with certain animals may justify awarding them priority.

None of these reasons are exhaustive. But they help to show that while such conflicts will undoubtedly be hard to solve and require further philosophical attention, we ought not to settle for a hierarchical account of dignity. Indeed, sentient dignity has good prospects to vindicate this idea. Recall that the claim defended here is not that sentient dignity is an equal but a symmetrical status – meaning everyone possesses the same fundamental rights. In contrast, claims to moral equality are comparative: they are expressive of the attitude that duty-bearers should have relative to two (or more) individuals (Floris, 2023). To answer questions of moral equality, an account of sentient dignity would have to show why variations in sentience are morally irrelevant by appeal to a ‘fitting, basic and independent moral attitude’ (idem, 232). ²⁶ That is too large a task to tackle here. However, note that sentient dignity does capture a significant component of why moral equality is often thought to be relevant, because it can reject hierarchy. Claims to moral equality often involve claims that each individual should have the same inclusion in decision-making, i.e. that no one should receive more fundamental consideration than others (Degrazia, 2008; Sangiovanni, 2024: 117–119). Because it does away with problematic distinctions at the basis and extends the same fundamental rights to all, the concept of sentient dignity already secures this. In short, although complex questions remain, these are issues which a dignitarian approach is equipped to address.

Why sentient dignity?

Basing dignity on sentience alone avoids the three problems above. But why focus on dignity in particular? Does dignity play a sufficiently non-redundant and meaningful role? There are two ways to understand this challenge. ²⁷ One is as a generalised scepticism about the usefulness of dignity, whether it applies to humans or animals (Bagaric and Allan, 2006; Macklin, 2003; Sangiovanni, 2017). Here, the worry is that dignity should have a unique normative function. If it lacks that function, then we should simply focus on sentient rights instead (see, for instance, (Cavalieri, 2002; Cochrane, 2013)). Another is more targeted: it may be that extending dignity to animals in particular is a misguided idea (Zuolo, 2016). On one reading of the literature on dignity, the entire purpose of dignity is to implement a strict demarcation between humans and other animals (Kymlicka, 2018; Rossello, 2017a; Shaw et al., 2024: 207). We can observe this via the dignitarian focus on distinctly human capacities such as rationality, personhood and moral agency (Griffin, 2008; Kant, 1785/1997; Kateb, 2011). It is also present in more ‘aristocratic’ conceptions of dignity (Fasel, 2024: chap. 3) that socially assign a ‘high rank’ to members of the human community alone (Killmister, 2020: chap. 5; Waldron, 2012). If the exclusionary challenge is correct that it is objectionable to exclude other animals as bearers of dignity, then dignity appears fundamentally redundant. The very point of upholding dignity would rest on a harmfully mistaken assumption. This section argues that there are good philosophical and strategic reasons why sentient dignity resists both versions of the redundancy challenge. ²⁸

Let us start with the philosophical considerations. Dignity signifies a unique kind of direct moral status that is irreducible to other concepts. An account of sentient dignity maintains the features of this status but is more inclusive in applying to all sentient beings. A conception of sentient rights could be developed without relying on dignity, but it would not necessarily have the five features that jointly constitute what it means to possess dignity: ²⁹

Inherent value: dignity supervenes on the (sentience-based) inherent value of its bearers. ³⁰ It is in virtue of their inherent value that a being has dignity (Debes, 2009: 61). ³¹

Claimability: dignity signifies that a particular being is the object of a range of directed duties held by agents (Wallace, 2013; Zylberman, 2017: 936–937), arguably both positive and negative (Gilabert, 2023: 23–27). ³² These duties correlate with the dignity-bearer's rights.

Universality: dignity is based on a ‘relatively general and important’ (Gilabert, 2023: 15) feature or set of features of individuals (their sentience). ³³ Hence, it is neither ‘restricted to special relationships’ nor ‘contingent on specific acts or relationships’ (Zylberman, 2018: 746).

Robustness: dignity signifies the separateness of its bearers (Rawls, 1971: 27). A dignity-bearer ‘matters not merely because of how useful’ they are (Bader, 2023: 167). As such, duties towards them are ‘especially exigent’ and typically prohibit ‘sacrificing the dignity of a single person for the greater well-being or even the dignity of others’ (Zylberman, 2016: 201–202). ³⁴

Symmetry: all dignity-bearers have the same status. One sentient being's dignity mirrors another's (Zylberman, 2018: 746). As explained above, this means all dignity-bearers have the same fundamental right(s), even if their derivative rights might vary.

Because it comprises these five necessary features, dignity has a determinate philosophical function: it bridges the gap between interests and rights (Gilabert, 2018: 204–209, 2024: 27). Although dignity therefore implies a conception of sentient rights, ³⁵ it is not exhausted by a conception of sentient rights. Instead, dignity is the status that explains who possesses rights, why they do so, and how they protect their bearers. In answer to the who question: dignity's basis in sentience tells us that it is all sentient beings that have the same fundamental rights (feature (e)) irrespective of contingent social relationships or institutions (feature (c)). Social arrangements do not decide who bearers of rights should be, the possession of sentience does. What's more, we ought not merely focus on ‘interests’ without specifying their source, because this tells us little about which interests we should consider. ³⁶ In answer to the question of why sentient dignity-bearers possess rights: dignity tells us what the purpose of organising a system of rights is. Rights are claimable requirements held against particular agents (feature (b)) that secure the conditions in which an individual's dignity can be realised and they thus allow each of us to have a fair claim to have our interests respected, protected and fulfilled. For instance, your right to freedom from torture should secure you against torture, irrespective of the social circumstances (feature (c)), and even if torture might promote others’ interests (feature (d)). Ultimately, rights therefore exist to protect our sentience-based inherent value (feature (a)). Finally, in answer to how rights protect dignity-bearers: if a being possesses dignity, this places particularly demanding requirements on how we should act towards them (feature (d)) and how we should include them in our decision-making (feature (e)). These requirements come in the form of constraints prohibiting us from aggregating considerations about their interests with other being's interests or using them merely as means to an end. For instance, it is wrong to raise and care for pigs merely because this makes pork taste better. What's more, these requirements apply symmetrically to all sentient beings (feature (e)). No sentient being possesses a greater number or weight of fundamental sentient rights than others (even if their derivative rights might vary).

However, dignity is not simply a philosophical bridge. It is also a foundation for commitment to a holistic approach to theorising about morality and justice (Gilabert, 2018: chap. 8, 2023: chap. 1). A dignitarian approach therefore allows us to deploy a network of structured moral concepts (Gilabert, 2018: 191–194), including the social dimensions of dignity such as norms concerning shame, humiliation, recognition and cultural markers of respect (Abbate, 2020; Coghlan, 2024; Killmister, 2020). ³⁷ For instance, we can make sense of the ways in which someone's dignity can both be inherent and fragile (Gilabert, 2018: 122–126). It is inherent because it is possessed as a universal and symmetrical status deriving from their sentience-based value. This is the status of dignity. Yet, it is fragile because that status is also a condition that must be realised in social circumstances. While all sentient individuals have dignity, many sentient individuals do not experience conditions in which it is in fact realised. A focus on dignity as the basis for rights therefore makes sense of and applies to a range of philosophical issues, because it provides dignity with a ‘deeper and more structural role’ than other accounts (Gilabert, 2024: 29). Dignity ‘immediately links up to several distinctive and important roles in human rights discourse which would be less apparent if we just used “moral status”’, or a similar alternative term (Gilabert, 2018: 147).

In this sense, sentient dignity continues to provide discourse surrounding human rights with philosophical coherence and explanatory depth, as will be touched on further below. It can do this because the account offered here is neither merely descriptive nor stipulative. Instead, it is a ‘deliberative interpretative proposal’ to ensure ‘human’ rights are plausibly inclusive and philosophically sound (Gilabert, 2018: 118). This means that it can maintain a degree of ‘continuity’ with the practice of human rights – all the features of dignity relied on above can be found within human rights discourse (ibid: 194–199). However, it also ‘involves an interpretation of the practice [of human rights]’ and provides ‘a view of… how it could be developed’ (ibid: 118). It does not therefore seek to simply describe what dignity is in the context of human rights. Instead, it aims to make sense of what people are referring to when they claim that human rights are underpinned by dignity, and it offers prescriptions for how dignity should be progressively and coherently developed. ³⁸ Most significantly, it departs from the scope often found in human rights literature: it extends ‘beyond the human’ (Perry, 2023a) to include any animal with the capacity for sentience. A conception of sentient dignity should therefore result in the robust legal protection of human and animal rights (Kotzmann and Seery, 2016: 35).

This revisionary prescription is plausible even though in much of the human rights literature the scope of humanity is claimed to be central to human rights practice. Some proponents of a distinctly ‘human’ dignity argue that this centrality is required to ensure the inclusion of the most vulnerable humans (Dupré, 2013; Phillips, 2015). Indeed, these approaches are premised on the very idea of ensuring the inclusion of those humans lacking a complex capacity for rationality (Fasel, 2024: 66–69). And yet, sentient dignity also secures the inclusion of the vulnerable without human supremacism, and it does so on a more stable footing. This is not only because it overcomes the challenge of exclusion, but also because it is not vulnerable to objections of arbitrariness (like many approaches that focus on humanity as a social category (Fasel, 2024: 69–71; Perry, 2023a)).

A second set of considerations in support of dignity are strategic. The term ‘dignity’ is not going to disappear from contemporary socio-political discourse, legal documents and everyday parlance. It is a symbolically valuable notion that is often harnessed to bridge cultural divides (Riley, 2019). As a tool for achieving greater inclusion for animals, adopting the concept of sentient dignity therefore has the potential to be strategically beneficial. Integrating sentient dignity into political, legal and everyday contexts means harnessing dignity's symbolic value in human rights law and practice (Kotzmann and Seery, 2016). The goal here would not only be to achieve greater protection of animals’ morally important interests – for instance through the creation of new legal regulations, public policies and revised personal attitudes towards other animals – but to overturn our focus on the idea that dignity can and should demarcate humans from other animals. ³⁹

Appeals to dignity are often used as a way of uniting diverse perspectives within human groups. These appeals pull on our ‘tribalistic’ (Jaquet, 2022: 939) tendency to favour in-group as opposed to out-group members (Clark et al., 2019). ⁴⁰ They do this by framing humanity as a single in-group to which we all belong (Killmister, 2023). Dignity thus harnesses our psychological tendencies to counteract exclusionary practices via appeal to our common humanity compared with our different sex, race, class, or citizenship. ⁴¹ This strategy of appealing to a shared group is arguably found across social justice movements that attempt to counter oppression (ibid), as well as contemporary and ancient philosophy. For instance, Sangiovanni (2017: 5) writes that it is the Stoics to whom ‘we largely owe our contemporary conception of the ‘unity of mankind’, the idea that all human beings share a fundamental status that binds us together as a species’. As the problem of exclusion makes clear, humanity is not a plausible ground for dignity, and we ought to reject tribalism as a philosophical justification for the human-animal divide (Figdor, 2021; Jaquet, 2021, 2022). Yet, if dignity is strategically unifying across seemingly diverse groups, then it is an important political and legal idea (Riley, 2019: 446).

The notion of sentient dignity can make sense of this by doing double duty. First, it can harness our psychological tendencies by appeal to a shared in-group. A relevant feature of tribalism is ‘how little the nature of the groups in question matters’ for this phenomenon to occur (Jaquet, 2022: 939), as long as members perceive themselves as belonging to the relevant group. Sentient dignity draws on this. It demands that we focus on a plausibly and justifiably inclusive social group as the basis for what we have in common with others: all bearers of sentience. Harnessing this might therefore help us to think of the community of sentience-bearers as a single tribe of dignity-bearers. Second, thinking of animals as members of our shared group provides philosophical coherence to the political discourse surrounding what we have in common, grounded in qualities that we share despite our differences (Gilabert, 2018: 114–121). If we adopt an account of sentient dignity the idea that we possess an inherent value in common with other bearers of dignity can be maintained: it is not our common humanity, but our shared sentience that generates the inherent value at the basis for dignity. However, it does so whilst also plausibly applying to almost every human and nonhuman animal irrespective of their species, age, or capabilities. If part of the reason dignity is politically valuable is precisely because it can apply across legal systems and normative orders (Riley, 2019), then sentient dignity allows us to make sense of this political value while including animals.

One concern is that this approach may backfire given the legacy of dignity as a form of exclusionary human supremacism. If dignity has historically been used to assert a human–animal divide, then the more dignity permeates public discourse, the harder it may be to fight speciesist prejudices. The enshrinement of ‘animal dignity’ in the 2008 Swiss Welfare Act is a case in point here (Swiss Confederation, 2008). This legal extension of dignity to animals might seem to be progressive on the face of it. Yet, article 3 of the act explicitly writes that ‘if any strain imposed on the animal cannot be justified by overriding interests, this constitutes a disregard for the animal's dignity’ (Ibid). In other words, if they are used for human interests, then the mistreatment of animals does not constitute a violation of their dignity according to Swiss law. What is troubling here is both that the instrumentalization of animals is enshrined into law, and that this is claimed to be consistent with respect for animals' dignity (Bolliger, 2016: 344). Shaw et al. (2024: 4) argue that this is a ‘new and different type of dignity’ because it problematically relativises dignity, and for this reason works against rather than in support of animals' interests. For this reason, the conception of animal dignity in Swiss law appears to be confusing, inapplicable and unhelpful (Persson et al., 2017). It departs from and directly conflicts with what it actually means to possess dignity, as outlined above. Shaw et al. (2024) may therefore be right that animal dignity should be abandoned.

Yet, this need not mean that we should abandon sentient dignity. The above concerns ought to be taken seriously: the point here is that sentient dignity has the potential to be of immense strategic value to achieve greater recognition of and protection for animals' rights. The Swiss case shows that achieving this depends on dignity being properly framed and deployed. The first lesson is that we should not advocate for ‘animal dignity’ and for ‘human dignity’ as separate notions precisely because this reinforces human-animal in-groups and out-groups and thus provides space for the instrumentalization of animals. Part of the strategic benefit of sentient dignity lies in the fact that it can help us to collapse that divide by applying it to both humans and animals. Another lesson is that in extending dignity to all sentient beings, we should not water it down (in the Swiss Act the protection of animals does not even preserve their right to life (Bolliger, 2016: 361; Shaw et al., 2024: 5)). Any promotion of sentient dignity must ensure it stays faithful to the genuine meaning of dignity to avoid it becoming a relativised and a metaphysically vague concept (Persson et al., 2017). As we saw above, dignity expresses a particular kind of status that we should be transparent about. In defending sentient dignity, we should centre the role of sentience as the basis for dignity to make clear what we should be protecting, and why.

Conclusion

An account of sentient dignity is the most plausibly inclusive way to overcome the problem of exclusion: it ensures that all humans and many, if not all, animals can be understood as bearers of dignity and dignity-based rights. It is tempting to simply extend the list of valuable capacities at the basis for dignity beyond rationality alone, to include empathy, cooperation, aesthetic appreciation, and even sentience, among others. However, the arguments above show that this move produces at least three problems: (i) it risks over-inflating the scope of dignity; (ii) it struggles to account for complexity; and (iii) it generates problematic moral distinctions. Although some complex questions remain to be addressed, an account of dignity based on sentience alone overcomes these problems. What's more, it can do so while maintaining the non-redundancy, philosophical coherence and potential strategic value of dignity. Humans and animals have something in common despite our differences: a shared capacity for sentience, and so, a shared dignity that extends across the species.

This has several revisionary implications for ethics, law, political activism and public policy. There are at least five that are worth mentioning in closing, and which merit further work. First, sentient dignity is a stable and robust strategic platform for a broad coalition in support of human and animal rights. This requires us to revise a number of legal and socio-political frameworks, including those used in human rights scholarship (Fasel, 2024; Stucki, 2023) and our political systems (Cochrane, 2018; Donaldson and Kymlicka, 2013). Second, more research is needed into the notion of sentience, how to measure it, and how to address differences in the interests of sentient beings (Birch, 2024). The public should also be made more widely aware of the extent, kind and degree of sentience possessed by a range of animals so that this can better inform democratic decision-making. Third, an account of sentient dignity implies that many exploitative and harmful practices involving animals should cease, including for instance the rearing of farm animals for food and resources and the killing of ‘pests’, among other things. These are not simply issues in which we must ensure we minimise a harm to animals’ welfare. They are direct violations of sentient beings’ dignity, akin to those we would commit against similarly placed humans. We ought to adopt practices consistent with other animals’ dignity. However, questions remain about what shape regulations should take, and which practices involving animals can plausibly continue. Sentient dignity need not imply an end to all human–animal relationships. Fourth, there are also open questions surrounding how other animals’ interests should be actively promoted, especially within conservation practices, environmental concerns, and predator–prey relationships. Finally, because they possess sentient dignity, other animals are not only owed much wider inclusion in the above matters. They are also owed greater priority. Our primary focus on the interests of humans is not simply morally wrong – it fails to treat other animals with dignity.