Jonathan Birch

If you have that Merkur-Pankset view, or that family of views, I should say, where we're talking about something very evolutionarily ancient, supported by subcortical mechanisms, mechanisms in the midbrain at the top of the brainstem, and that is about evaluative modeling of the animals' priorities and needs, then there's a very clear function relating to decision-making.

If you have that Merkur-Pankset view, or that family of views, I should say, where we're talking about something very evolutionarily ancient, supported by subcortical mechanisms, mechanisms in the midbrain at the top of the brainstem, and that is about evaluative modeling of the animals' priorities and needs, then there's a very clear function relating to decision-making.

in that what sentience allows is, well, an escape from being a reflex machine and the possibility of weighing up quite different options in very flexible ways. So that view has some plausibility, I think. And I also think it's quite plausible that sentience facilitates learning. That if you think about that hot stove situation, Think about what the pain does for you.

in that what sentience allows is, well, an escape from being a reflex machine and the possibility of weighing up quite different options in very flexible ways. So that view has some plausibility, I think. And I also think it's quite plausible that sentience facilitates learning. That if you think about that hot stove situation, Think about what the pain does for you.

What it doesn't seem to do for you is trigger the reflex withdrawal of the hand because that's underway already. But what it plausibly does do is help you learn about where not to put your hand on future occasions. And that leads to a very interesting debate about what kinds of learning sentience facilitates and why.

What it doesn't seem to do for you is trigger the reflex withdrawal of the hand because that's underway already. But what it plausibly does do is help you learn about where not to put your hand on future occasions. And that leads to a very interesting debate about what kinds of learning sentience facilitates and why.

Well, as I say, I think the sentience candidate is a better concept in a way. Fair enough. And I suggest in the book that insects are sentience candidates.

Well, as I say, I think the sentience candidate is a better concept in a way. Fair enough. And I suggest in the book that insects are sentience candidates.

So in terms of cases where we have enough evidence to really compel us to take seriously a realistic possibility of sentience, we're definitely talking about all vertebrates and the cephalopod mollusk, like octopuses, squid, cuttlefish, and the decapod crustaceans and the insects that are both arthropods. And then... It could be that we're talking about something that has evolved three times.

So in terms of cases where we have enough evidence to really compel us to take seriously a realistic possibility of sentience, we're definitely talking about all vertebrates and the cephalopod mollusk, like octopuses, squid, cuttlefish, and the decapod crustaceans and the insects that are both arthropods. And then... It could be that we're talking about something that has evolved three times.

It could be something that is there in the common ancestor of all three groups, and we're not really in a position to have much confidence either way on that one.

It could be something that is there in the common ancestor of all three groups, and we're not really in a position to have much confidence either way on that one.

Yeah, over 560 million years ago, very small worm-like creature So, I mean, yeah, perhaps unlikely to possess the mechanisms that convince us in those three cases that sentience is a realistic possibility. So I suppose I perhaps lean myself towards the three origin view.

Yeah, over 560 million years ago, very small worm-like creature So, I mean, yeah, perhaps unlikely to possess the mechanisms that convince us in those three cases that sentience is a realistic possibility. So I suppose I perhaps lean myself towards the three origin view.

Exactly, yeah, particularly in those lineages where we see complex active bodies. This is Mike Trestman's term, where you have the challenges that come with trying to manage articulated bodies with lots of parts. And you can't be a reflex machine as such anymore because then different bits of the body will start tearing each other apart.

Exactly, yeah, particularly in those lineages where we see complex active bodies. This is Mike Trestman's term, where you have the challenges that come with trying to manage articulated bodies with lots of parts. And you can't be a reflex machine as such anymore because then different bits of the body will start tearing each other apart.

there has to be some kind of centralized, sophisticated control system in place. And that's when we seem to start seeing realistic candidates for sentience. And if that's true, then certainly the cephalopod mollusks and the arthropods are looking like candidates.

there has to be some kind of centralized, sophisticated control system in place. And that's when we seem to start seeing realistic candidates for sentience. And if that's true, then certainly the cephalopod mollusks and the arthropods are looking like candidates.

Yes, well, the octopuses have become poster children, as it were. They're often the case that gets people to take the possibility of invertebrate sentience seriously. And I think once you've got that far, you think, well, you know, are they really the only invertebrates for which there's relevant evidence? And no, they're not.

Yes, well, the octopuses have become poster children, as it were. They're often the case that gets people to take the possibility of invertebrate sentience seriously. And I think once you've got that far, you think, well, you know, are they really the only invertebrates for which there's relevant evidence? And no, they're not.