Sentience is fundamental to our existence. To survive we need to be are aware of what goes on around us, to be connected to, to perceive, the outside world. Because we are able to take in data relating to the world, we can also then try to make sense of it, process it, and so find ways to change things for our benefit.

But although sentience is fundamental to who we are and how we live our lives, the standard definition of the word does not imply any actual interpretation of the sensations we receive. That is left to other parts of our brains to deal with and other words, such as intelligence, used to describe those processes.

Sentience though is not confined to we humans. To have an awareness of the world we inhabit, we all have to have some degree of sentience. What each species does with that information is peculiar to it. It may do a lot or very little in response. It may not need to give it very much thought if it has automatic mechanisms in place to take advantage of more favourable conditions and/or defence mechanisms to protect itself from problematic conditions.

Those mechanisms however are themselves examples of sentience. For instance when it rains, the osmotic pressure across the semi-permeable membranes in the roots of even the humble grass ensures that water is absorbed into the blades of grass to take part in the photosynthesis required to make the grass grow.

So then, in that sense, every living thing has sentience. It responds to its environment and, to respond, it has to have been aware of the environment in the first place – to have been sentient.

There seems now however to be some degree of confusion over this. Legislation was enacted by Parliament in 2022 – the ‘Animal Welfare (Sentience) Act 2022’. it was promoted behind the scenes  by Boris Johnson’s then newly acquired wife. It required the formation of a committee to consider “whether, or to what extent, the government is having, or has had, all due regard to the ways in which [any new government] policy might have an adverse effect on the welfare of animals as sentient beings.

Recently, the definition of ‘sentient animals’ was extended to include any ‘cephalopod mollusc’ (octopus, squid, cuttlefish or nautilus) or ‘decapod crustacean’ (lobster, crab, shrimp or prawn). I imagine that they weren’t originally included because although Mrs Johnson no doubt liked her crustaceans very much, she preferred them on a plate.

Curiously, the Act contains no definition of sentience, but the pressure to include them within the ambit of the Act came not because they are sentient. After all, all living organisms are sentient. It came from the signs of intelligence and emotions which can be seen in their behaviour. In other words, in this legislation sentience has lost its former specific, narrow meaning. It has instead become another all-purpose word describing how a particular species reacts to what is going on, and with what degree of complexity.

And these days we, as humans, are increasingly likely to consider ourselves as part of a continuum and so not wholly exceptional in the world as we used to do. It would be lovely to think that we are nonetheless at the apex of animal development. In many ways we are, but in environments hostile to us, such as the sea, we are nowhere near. That’s where the cephalopod molluscs and decapod crustaceans rule.

The change in the way we see ourselves, however, has certainly been encouraged by animal rights campaigners. The extremist animal rights organisation, PETA, says:

“Animal rights helps us to look past the arbitrary distinctions between different species, to rediscover our innate compassion and to respect all animals equally. "When it comes to pain, love, joy, loneliness and fear, a rat is a pig is a dog is a boy. Each one values his or her life and fights the knife."

But are the differences between different species actually arbitrary? Certainly the differences can be regarded as differences of degree. But what starts out as a matter of degree can change into a difference in kind.

It is for instance rather difficult to say that the difference between a model T Ford and a Ferrari is only one of degree because they both have engines and four wheels. Are roses only different in degree from grass because they both have roots and fronds?

The emotions that we display, including grief, happiness, friendship, anger, curiosity and frustration exist in other primates. Chimpanzees are generally held to be the primates nearest to us in their capabilities and social lives, but are they really only different in degree? Some of these same emotions exist to some extent in animals further down the chain, such as mice. Although they benefit from having social interactions, no-one has ever shown that mice engage in a period of mourning for a cousin lost in a mouse trap.

And so does not the difference of degree turn at some point into a difference in kind?

We know that reactions such as pain are there to tell us that we may be injured if we don’t back off. Our system of senses and emotions largely motivate us to act in our own best interests.

Although play is commonly found in other animals, it is there to encourage the formation of useful skills. I would hazard a guess though that not all of our emotions are so directed. Instead, some are are probably also self-replicating memes, such as Daniel Dennett proposed was the case with religion. Such things as art, music, poetry, darts, football and so on do not have any obvious or significant survival benefit for us, although they may though stop us from being bored. Can you imagine having the life of a cow – eating grass, chewing the cud and belching methane? And not going mad with the boredom?

And by the same token, we can reasonably infer that cows do not need the varied inner world which we possess, presumably because their awareness of themselves and their futures is far less acute than ours.

And then there is the question of intelligence. The level of intellect of a mouse is clearly a lot less than that of a chimp and that of a chimp is a lot lower than ours. They are therefore unable to solve problems of any complexity or make the discoveries or inventions typical of human-kind. They will necessarily therefore understand the world (and react to it) in an entirely different way. Again, surely not just a difference of degree?

Our emotions are an integral part of how we avoid danger, find food and find mates. But it does not mean that emotions are felt in the same way by all animals or with the same intensity.

Our own emotions are not just a reaction to what is then happening to us, but also what has already happened to us. And they reflect our knowledge of what may happen in our future. Lower order animals, having no real ability to work out what the future holds, at least beyond the next minute or two, would not have that additional element to their emotions. And so their view of their lives would inevitably be very different to ours.

For all these reasons, I find the PETA position really rather silly, and will continue to do so until the lion really does lie down with the lamb. After all, if the lion claims animal rights then that surely ought to be accompanied by its recognition of those rights for other animals.

Instead, we quite correctly describe nature as being red in tooth and claw. We mainly find it difficult not to feel empathy towards (other) animals. Even watching Sir David Attenborough’s nature programmes can be rather harrowing.

However, apart from our own squeamishness or wish to see ourselves as better, on a higher plane, than the other animals, why should we behave with care towards a member of another species if that species is about to hunt down a tasty member of yet another species? A rat is not a pig, which is not a dog, which is not a boy.

21 May 2024

Paul Buckingham