A Virtue of Precaution Regarding the Moral Status of Animals with Uncertain Sentience


We address the moral importance of fish, invertebrates such as crustaceans, snails and insects, and other animals about which there is qualified scientific uncertainty about their sentience. We argue that, on a sentientist basis, one can at least say that how such animals fare make ethically significant claims on our character. It is a requirement of a morally decent (or virtuous) person that she at least pays attention to and is cautious regarding the possibly morally relevant aspects of such animals. This involves having a moral stance, in the sense of patterns of perception, such that one notices such animals as being morally relevant in various situations. For the person who does not already consider these animals in this way, this could be a big change in moral psychology, and can be assumed to have behavioural consequences, albeit indeterminate. Character has been largely neglected in the literature, which focuses on act-centred approaches (i.e. that the evidence on sentience supports, or does not support, taking some specific action). We see our character-centred approach as complementary to, not superior to, act-centred approaches. Our approach has the advantage of allowing us to make ethically interesting and practically relevant claims about a wider range of cases, but it has the drawback of providing less specific action guidance.

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  1. 1.

    That is, sentience in the sense of a capacity to experience pain or suffering. A capacity to feel bad; to have mental states that are affective and aversive or that have negative valence of the sort recognised by many ethical theories.

  2. 2.

    Broom (2013, p. 152) draws the weaker conclusion that “there is a case for some degree of protection for spiders, gastropods and insects,” without specifying the step from the empirical to the normative.

  3. 3.

    Examples of such judgements have been given above.

  4. 4.

    For an overview of notions to this effect, see Hansson (2013), Munthe (2016), and Steel (2014).

  5. 5.

    E.g., Mather (2011) discusses contractarian, utilitarian and rights-based approaches, but not approaches focusing on virtue or character.

  6. 6.

    For an overview, see Akhtar (2011).

  7. 7.

    The number 1018 is from Hölldobler and Wilson (2009, p. 5), which refers to a calculation by Williams (1964). The number 1019 is from the Entomological Society of America (2010), which says that according to E. O. Wilson, there are nearly 1019 insects. The numbers 1018 and 1019 may refer partly to animals that are sometimes no longer classified as insects; in particular, springtails, which are tiny, extremely numerous organisms. When they were considered insects, they were the most numerous insect (Hopkin 1997 front flap).

  8. 8.

    For more on this topic, see Tomasik (2016c).

  9. 9.

    A reply to the doubt that the suffering may not be sufficiently severe is to make a conservative assumption about the likelihood that the beings’ suffering is sufficiently severe, although it would make the argument more complicated.

  10. 10.

    As Sandin et al. (2002, pp. 292–293) notes, “cautiousness in one respect often leads to incautiousness in another.”

  11. 11.

    Consistency requirements of this sort on precautionary recommendations have been suggested by, e.g., Munthe (2011) and Steel (2014).

  12. 12.

    Both Lockwood and Eisemann and colleagues here speak of respect for living organisms, but they seem to have the possibility of sentience in mind. Others, however, emphasize respect for life (seemingly life itself). For example, Adamo (2016, p. 78) says that “insects should be handled with care for reasons that do not hinge on whether or not they experience pain…. All research animals should be handled in a way that reflects a respect for life, regardless of their ability to experience pain.” A respect for life is different from the disposition we are concerned with in this section: attention and cautiousness when there is sufficient uncertainty about sentience.


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We are grateful to Oscar Horta, Brian Tomasik, Bengt Brülde, Dorna Behdadi, Ragnar Francén, Peter Singer and especially Joakim Sandberg for generous feedback on earlier versions of this paper. We also thank Benjamin Martens and Gordon Hanzmann-Johnson for improving the English of earlier versions of the paper.

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Correspondence to Simon Knutsson.

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Knutsson, S., Munthe, C. A Virtue of Precaution Regarding the Moral Status of Animals with Uncertain Sentience. J Agric Environ Ethics 30, 213–224 (2017). https://doi.org/10.1007/s10806-017-9662-y

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  • Ethics
  • Insects
  • Invertebrates
  • Fish
  • Pain
  • Sentience