Written by Roger Crisp

Last week, at a seminar organized jointly by the Oxford Uehiro Centre and the Wellcome Centre for Ethics and Humanities, Prof. Irina Mikhalevich presented a fascinating preview of a paper (‘Minds Without Spines: Toward a More Comprehensive Animal Ethics’) which forms part of a project she has been working on with Prof. Russell Powell.

Animal ethics has burgeoned in philosophy since the publication of Peter Singer’s landmark essay ‘Animal Liberation’ in the New York Review of Books in 1973. Its focus has been largely on vertebrates, especially relatively large mammals, but this group, Mikhalevich pointed out, comprises only 0.1% of all animals. Mikhalevich mentioned several possible explanations for this lack of attention, including the belief that such animals, because their brains are so small, are not conscious. She then went on to explain how recent developments in cognitive science and neuroethology have provided evidence that many invertebrates may have capacities for complex cognitive and non-cognitive states, including pleasure and pain. Ants, for example, can recognize themselves in a mirror, something which human beings achieve typically only when nearly two years of age. And something analogous to our ‘dopamine’ system has been found in certain invertebrates. Indeed, given the adaptive benefits of pain perception, one would expect this, or something analogous to it, in at least those invertebrates which can learn to avoid painful stimuli.

It is highly plausible to believe that capacity for pleasure and pain, or other affective states, is a necessary condition for moral standing. But it has to be admitted that invertebrates, and any mental lives they may have, are significantly less complex than those of animals standardly thought of as ‘higher’. So it might be thought that, though they have moral standing, that standing is vastly lower than that of the higher animals, and hence practically irrelevant. This may be true, but it is far from obvious, and requires argument. Some believe, for example, that all animals are to be treated equally, or even that justice requires that some priority be given to lower animals, on the ground that they are worse off – that is, their lives are less good for them overall than the lives of many higher animals are for them.

Would extending the moral circle to include invertebrates – accepting what we might call ‘spineless ethics’ — have major practical implications? Mikhalevich suggested that it may not, since it could turn out that the number of invertebrates with moral standing is relatively low, and the interests of such creatures may be less significant than those of vertebrates. As I just mentioned, and Mikhalevich herself admits, this second suggestion can be questioned. And of course it may be that the number of invertebrates with moral standing is, though relatively low compared to the total number of invertebrates, absolutely very large indeed.

Here are two possible implications of spineless ethics. First, we may be required to revise our current practices involving the extermination of invertebrates in agriculture, especially if they involve inflicting pain. There are difficult issues here involving aggregation, as Mikhalevich noted, but huge numbers of painful experiences, even if they are quite short, cannot be ignored, especially if it were possible (as it may well be) for human beings to live happy and healthy lives without such practices. Second, we may have to reconsider our attitudes to the badness of certain catastrophic events, such as a rise in global temperature which resulted in the extinction of higher species but left the world inhabitable by sentient invertebrates. We humans tend to think primarily of ourselves, or at least the higher animals, when considering the total amount of happiness on the planet. But given the numbers involved, our contribution to that total, on some not implausible views of aggregation, may be relatively trivial.