The government has finally caught up with what most animal behavioural scientists have been saying for years by formally recognising animals as sentient beings in its animal welfare (sentience) bill. In November it was confirmed that the scope of the bill would be extended to include in the “sentient” category all decapod crustaceans (such as crabs and lobsters) and cephalopods (including octopuses, squid and cuttlefish). This ruling heeds a review led by Jonathan Birch of the London School of Economics, who points out: “Octopuses and other cephalopods have been protected in science for years, but have not received any protection outside science until now.”
Although these rulings are welcome, their tardiness is sobering. People have been arguing fiercely, dogmatically and even violently about animal welfare for a very long time – yet framing the issue in terms of legally enforced rights comes with baggage about the socially constructed (and therefore exclusively human) nature of moral status and rights-based reasoning. The starting point should rather have been the nature of animal cognition: how we and other beings are situated in a broad panorama of minds. While there is still plenty to learn about that mindscape, Birch is right to imply that, given what science has already told us, it borders on the absurd that UK law took so long to formally acknowledge animal sentience.
There was, however, a long historical tradition of human prejudice and exceptionalism to overcome. Aristotle distinguished humans from other animals by asserting that only we have a “rational soul”, in addition to the “sensitive soul” of animals. In the 17th century René Descartes notoriously asserted that animals are mindless mechanisms, so that we shouldn’t mistake signs of apparent pain or distress as an indication that brute beasts truly feel anything at all. His supporters were accused of the most heartless acts of vivisection (although Descartes himself was said to be devoted to his dog, Monsieur Grat).
Charles Darwin’s claim that there are “no fundamental differences between man and the higher mammals in terms of mental faculties” didn’t deter the radical behaviourist psychologists of the 1950-70s, such as BF Skinner, from returning to something like the Cartesian view of animals as automata. (Skinner saw no ethical problem in training pigeons to be living guidance systems inside bombs.) Not until the modern age of neuroscience have we truly begun to recognise a continuity of neural hardware and cognitive ability between us and other animals.
Still the question lingers of whether there is some fundamental difference of mind that makes humans special. Certainly, the sophistication of our language, and perhaps in consequence of our culture, seems unique. But there’s no reason to suppose that the capacity to experience pain, curiosity, empathy and other felt aspects of existence belongs to humans alone.
Some biologists now argue that sentience may be a property of all living things, even bacteria and single cells. They assert that plants, despite lacking a nervous system, show signs of genuine cognition, even feeling. But if it is still disputed at what point in the living world sentience begins, the view expressed by philosopher Daniel Dennett is now common: “Sentience comes in every imaginable grade and intensity, from the simplest and most ‘robotic’, to the most exquisitely sensitive, ‘hyper-reactive’ human.”
The concept of sentience liberates the debate from the more contentious matter of whether other animals are conscious: a question in which the obsolete Enlightenment view that “human reason” is like a divine spark activated within us is still discernible. A ghost of Aristotelian exceptionalism remains in the suspicion that, while other animals may be sentient, only humans have that special form of it we call consciousness. The problem is that it’s hard to assign clear, quantifiable meanings to these words – even in humans, where, for example, arguments rage over the cognitive status of people in a permanent vegetative state after brain trauma (that very term harking back to Aristotle’s view of plants as possessing a mere “vegetative soul”). Although we might not know or agree on what consciousness is, it looks increasingly peculiar to imagine it as a single and absolute cognitive attribute.
The question for animal welfare is how the evident differences in “qualities of mind” between species colour our attitudes and obligations. One commonly cited criterion is whether other animals experience pain. American neuroscientist Joseph LeDoux argues that emotions such as pain are human-specific responses to physiological reactions: narratives we alone can create because of our linguistic capacity (for example, “I’m hurting”). Others counter that, since all observable indicators of and responses to “pain” in, say, dogs or chimps, look like those in us, it makes no sense to imagine some fundamental difference. At any rate, the humane position is surely to assume an equivalence unless we have clear reason not to.
And it’s not just about physical pain. Experiments have shown, for example, that farmed pigs respond as if “depressed” when kept in barren conditions devoid of mental stimulation, responding to signals (about food, say) as if they have acquired a pessimistic lack of interest in things that might benefit them. Again, we don’t know what that situation feels like to a pig – but they do seem to have a response to their experience that displays a sensitivity to the richness (or not) of their surroundings.
One challenge is how to avoid framing this debate in anthropomorphic terms, to assess rights on the basis of how closely an animal seems to approach human-like cognition. Cephalopods in particular have suffered from that tendency. The common ancestor we share with them probably lived about 600m years ago – far more distant than that of all vertebrates, such as fish – and their nervous systems are very different: most of an octopus’s neurons are in the arms, not the central brain. Some researchers think they might have a kind of dual or even multiple consciousness – a bizarre situation we struggle to imagine. Octopuses are “probably the closest we will come to meeting an intelligent alien”, says philosopher Peter Godfrey-Smith. For octopuses do show signs of considerable intelligence, even if their motives can be hard to deduce. For this reason, in 2019 more than 100 experts in cephalopod cognition called for a ban on octopus farming in “sterile, monotonous” environments.
In the end, the notion of “rights” is hugely anthropocentric. Even the rights of, say, human embryos or people in untreatable comas (which might be argued to have less sentience than a chimp) are framed in terms of the potential for human experience. The Great Ape Project makes a compelling case for rights among our closest primate relatives: to not be killed (except in self-defence), to be allowed freedom and dignity, habitat protection and freedom from intentionally inflicted physical and psychological pain. But while the often blunt instruments of law can be needed to prevent obvious abuses, the better question is not what animals “deserve” or should be granted, but what kinds of mind they have, and what obligations we humans incur towards them as a result.
The Book of Minds by Philip Ball will be published by Pan Macmillan in June.
Other Minds: The Octopus and the Evolution of Intelligent Life by Peter Godfrey-Smith (William Collins, £9.99)
Sentient: What Animals Reveal About Our Senses by Jackie Higgins (Picador, £20)