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Interspecies justice: agency, self-determination, and assent


In this article, we develop and defend an account of the normative significance of nonhuman animal agency. In particular, we examine how animals’ agency interests impact upon the moral permissibility of our interactions with them. First, we defend the claim that nonhuman animals sometimes have rights to self-determination. However, unlike typical adult humans, nonhuman animals cannot exercise this right through the giving or withholding of consent. This combination of claims generates a puzzle about the permissibility of our interactions with nonhuman animals. If animals sometimes have rights to self-determination, but lack the capacity to consent, then when, if ever, is it permissible for us to touch them, hold them, bathe them, or confine them? In the second half of the article, we develop a solution to this puzzle. We argue that while we cannot obtain animals’ consent, they can engage in authoritative communications of will through acts of “assent” and “dissent.”

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  1. 1.

    From this point on we use the term ‘animal’ to refer to nonhuman animals. Though convenient, this decision has two negative consequences. First, it implies that humans are not animals, which of course we are. Second, it obscures the diversity that exists between different animals. See further fn. 3.

  2. 2.

    See also, Donaldson and Kymlicka (2011, 2015, 2016b).

  3. 3.

    Throughout the paper, we often make general claims about animals. We do so, despite great variation in the animal kingdom, to simplify the exposition of the argument. Specifying which animals these claims apply to would require detailed empirical work about which animals possess the kinds of capacities we highlight as significant. However, we suspect that these claims can be defended for many subjectively aware animals.

  4. 4.

    Here and throughout we are particularly indebted to Groll’s excellent paper.

  5. 5.

    For this general conception of the grounds of rights see Raz (1986, p. 166).

  6. 6.

    For philosophical reflections on animal cognition and agency that are relevant to the discussion of this section, see DeGrazia (1996, 2009), Dretske (2006), Glock (2009), Regan (2004), Sebo (2017) and Thomas (2016).

  7. 7.

    To be sure, some people hold that personal autonomy is only of instrumental value for humans. However, insofar as proponents of this view nonetheless generally recognize robust autonomy rights for humans, for a variety of instrumental reasons, we believe that a very similar story can be told for many animals. Others hold that autonomy is not a constituent of well-being but an independent source of normative demands. Such a view is also compatible with our argument.

  8. 8.

    For accounts of the value of autonomy that put the exercise of agency front and centre, see Hurka (1987), Raz (1986, Ch. 13), Shiffrin (2004 and 2012).

  9. 9.

  10. 10.

    The idea that animals are autonomous is controversial and some may want to retain the label of “autonomy” for those with certain cognitive capacities (e.g. persons). We take no stand on this issue. To remain ecumenical, we refer to the good of animals in being able to exert control over their lives as the good of self-determination.

  11. 11.

    We address the question of how we should relate to non-competent animals in Sect. 5.

  12. 12.

    Of course, the precise specification of these general conditions is a matter of significant debate. Here we rely on an intuitive understanding of the conditions.

  13. 13.

    We do not mean to imply that nonhuman animals never possess anything that might sensibly be called a normative concept or attitude, nor that such attitudes might inform their actions and interactions. (For recent discussion see Andrews 2020.) We do, however, think that certain kinds of normative thought and activity, including those underpinning the power of consent, are likely to be almost exclusively human. Thanks to an anonymous reviewer for pressing us to clarify this.

  14. 14.

    Thus, while there are important continuities between, for example, the cognitive mechanisms underlying the social organization of the great apes, and the cognitive mechanisms underlying the social organization of humans, it also seems clear that there are important discontinuities when we consider human practices of politics, law, and interpersonal morality. We speculate that these differences emerge as a result of the different kinds of normative thought and action that many human beings are capable of.

  15. 15.

    An anonymous reviewer drew our attention to an important recent article by Charlotte Blattner that addresses this challenge in the context of animal labour (Blattner 2020).

  16. 16.

    Christine Korsgaard offers a clear articulation of this abolitionist argument (which she later rejects, albeit for different reasons). See Korsgaard (2018, pp. 176–179).

  17. 17.

    There has been some discussion of the relevance of animal “assent” and “dissent” in the context of biomedical research (see, for example, Fenton 2014; Kantin and Wendler 2015; Ferdowsian et al 2020). These authors overlook the possibility that animals have a right to self-determination that underpins the significance of their assent, and they tend to be much more pessimistic about securing valid assent. By contrast, we offer a more thoroughgoing account of how and when animal assent is normatively transformative in the context of everyday human-animal interactions.

  18. 18.

    For this reason, we bracket the question of how our account of assent and dissent applies to relationships between humans.

  19. 19.

    The idea of assent developed in this paper is intended to guide us in realizing just interspecies relations. Incarcerating animals in research facilities and using them as test subjects is antithetical to respecting them as subjectively aware agents with basic rights, so the issue of whether animals can assent to particular interactions in biomedical research contexts is generally beside the point.

  20. 20.

    Throughout the paper, we focus on one-off interactions to demonstrate how the assent and dissent of animals can be normatively transformative. The discussion leaves untouched whether, and in what ways, animals can assent to the more fundamental dimensions of their lives such as where they live, who they live with, and what they do more generally. While we hope that our account offers a starting point for addressing these issues, we cannot adequately deal with them here. For a discussion of closely related issues in the context of animal labour, see Blattner (2020).

  21. 21.

    Note that the “can” that features in the description of this case should be read as referring to non-normative beliefs on Hubert’s part (i.e. beliefs about what Hubert is physically able to do, and about how Dan usually behaves) rather than a normative belief (about what Hubert and Dan are permitted or entitled to do). Thanks to an anonymous reviewer for highlighting this ambiguity.


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Thanks to audiences at the Canadian Philosophical Association meeting in Montréal 2018, the Global Ethics Tea Seminar at the University of Birmingham, the Political Theory Research Group at the University of Edinburgh, and the Political Philosophy and Theory Group at the University of Glasgow, for useful feedback on this paper. Special thanks go to Sue Donaldson, Valéry Giroux, Will Kymlicka, Jonathan Parry, Daniel Viehoff, and an anonymous reviewer for this journal for written comments and discussion. Extra special thanks go to Mr BW for whom this paper was written.

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Correspondence to Richard Healey.

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Healey, R., Pepper, A. Interspecies justice: agency, self-determination, and assent. Philos Stud 178, 1223–1243 (2021).

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  • Nonhuman animals
  • Interspecies justice
  • Agency
  • Self-determination
  • Consent
  • Assent
  • Dissent