I don’t find that obvious at all. I agree there is nothing special dividing vertebrates from unicellular organisms, but I definitely think that some kind of CNS is required for the experience of emotions like fear, happiness etc. I do not see at all how paramecium could experience something like that. What part of it would experience it? Emotions in humans seem to be characterised by particular patterns of brain activity and concentrations of certain molecules (hormones, etc). I really cannot see how a unicellular organism has any capacity to experience emotions as we do. I would also argue that there is no dividing line between life and non-life. Whether something is alive or not is quite nebulous and hard to define. As you say, viruses are a good example but there are many others. Eg. a pregnant mammal. The foetus does not fill the classical, basic conditions of life that are taught in school (MRS H GREN, or whatever acronym) but does it really make sense to say that it is not alive? How many organisms are there when we look at a pregnant mammal. It is not clear.
but I definitely think that some kind of CNS is required for the experience of emotions like fear, happiness etc.
okay, so when a scallop runs away from you it doesn’t feel fear?
and when a paramecium is being ensnared by a hydra or some weird protist on your microscope slide, and it’s struggling to get away, it doesn’t feel fear? lol
Obviously every moving living thing can feel fear, that’s why they’re moving living things and that’s why they run away from predators
I would also argue that there is no dividing line between life and non-life. Whether something is alive or not is quite nebulous and hard to define
With a few exceptions like viruses, it’s pretty obvious. Rocks don’t make more rocks, nor does water
I’m not sure if scallops can run…
But if you mean something like a mollusc, for example a snail, then I think it depends on which organism it is. I think a snail probably does feel fear yes in a very primal way. A bivalve like a scallop I’m not so sure, they have very basic nervous systems. An octopus I think is capable of fear and other more advanced emotions too, most likely. However, I think when we ascribe emotions to these animals we are anthropomorphising them. We have no way to know what their experience is like and we are sticking our human labels on them. Especially for a group such as molluscs, which diverged a very long time ago from the lineage that led to us. The feeling of fear, the understanding of danger and need to get away from it could be very primal and exist in many animals, but they may also feel it very differently to how we do. For example ants, I imagine a worker and does not feel fear for itself but rather the colony.
Unicellular organisms mostly move on the basis of concentration gradients, towards food and away from toxic things or predator signals. When one is struggling and being engulfed by a hydra or other unicellular organism, I don’t think it feels anything no. I think it is just trying to move away from the predator because it detects a molecular signal that it is “programmed” to move away from. By programmed I mean that behaviour is encoded in the complex interaction of the many systems that make it up, such as through the concerted action of it’s receptors, signalling pathways, enzymes, genes etc.
Rocks and water are not what I was talking about. Take for example cell-free translation systems. These are basically all of the contents of a cell but without any of the membranes. Like empty a cell into a (small) bucket. They still perform all of the biochemical reactions that took place in the normal cell. But they are not in a sack. There is no unified “thing” and it doesn’t move. If you did that to a paramecium, could that liquid still feel fear? It cant move away from anything. Is it alive? What makes something alive? Life is ultimately the sum of many complex biochemical reactions, but no one part of it is alive. Enzymes themselves are not alive surely. One single neuron is not alive.
If you had a human brain in a jar and, for arguments sake, it could still think as normal. It is intelligent and sentient, but it cannot replicate itself. But a virus, which is still much more simple than the brain in a jar, can. When you say that rocks don’t make more rocks, you seem to imply that the quality of life is in replication.
just youtube it, they can
and if they can do that, then of course they can feel fear too
When one is struggling and being engulfed by a hydra or other unicellular organism, I don’t think it feels anything no.
wild
I think it is just trying to move away from the predator because it detects a molecular signal that it is “programmed” to move away from.
replace the hydra with a tiger and the amoeba with a deer, how is it any different apart from the number of cells? The deer prey could maybe have conscious thoughts/sorrow about its children during the last seconds of its life, but other than that the fear is fundamentally the same, it’s just more complex/scaled up
By programmed I mean that behaviour is encoded in the complex interaction of the many systems that make it up, such as through the concerted action of it’s receptors, signalling pathways, enzymes, genes etc.
sure glad we don’t have any of those
Like empty a cell into a (small) bucket. They still perform all of the biochemical reactions that took place in the normal cell. But they are not in a sack. There is no unified “thing” and it doesn’t move. If you did that to a paramecium, could that liquid still feel fear? It cant move away from anything. Is it alive?
Uh, I’m not an expert but I would suspect they’re in the process of dying if you do that. They just don’t die immediately, because nothing does (even a person who gets shot stays alive for a few minutes afterward). Can you feed this cell jelly its normal food and have it sustain itself like usual? If not then I would say it’s only alive on technicality, just like a person who’s been shot in the head and can still talk for the next few seconds–they’re technically also alive! But the person will die once the last few bits of brain oxygen run out due to the mechanical reality of their heart not beating, and the cell-jelly-in-a-bucket will also die after some time due to the mechanical reality of their vacuoles or whatever not being able to properly absorb food (I’m guessing, anyway. But this isn’t really relevant to the central point)
If you had a human brain in a jar and, for arguments sake, it could still think as normal. It is intelligent and sentient, but it cannot replicate itself. But a virus, which is still much more simple than the brain in a jar, can. When you say that rocks don’t make more rocks, you seem to imply that the quality of life is in replication.
This is a disjoint coutnerexample, the point is not that a brain in a jar can’t replicate itself, but that the original organism that brain comes from, can. A man who gets a vasectomy is still alive, because his default state is being able to reproduce.
Rocks however, can NEVER reproduce. There is not A SINGLE rock that can reproduce. Therefore rocks are not alive.
I don’t find that obvious at all. I agree there is nothing special dividing vertebrates from unicellular organisms, but I definitely think that some kind of CNS is required for the experience of emotions like fear, happiness etc. I do not see at all how paramecium could experience something like that. What part of it would experience it? Emotions in humans seem to be characterised by particular patterns of brain activity and concentrations of certain molecules (hormones, etc). I really cannot see how a unicellular organism has any capacity to experience emotions as we do. I would also argue that there is no dividing line between life and non-life. Whether something is alive or not is quite nebulous and hard to define. As you say, viruses are a good example but there are many others. Eg. a pregnant mammal. The foetus does not fill the classical, basic conditions of life that are taught in school (MRS H GREN, or whatever acronym) but does it really make sense to say that it is not alive? How many organisms are there when we look at a pregnant mammal. It is not clear.
okay, so when a scallop runs away from you it doesn’t feel fear?
and when a paramecium is being ensnared by a hydra or some weird protist on your microscope slide, and it’s struggling to get away, it doesn’t feel fear? lol
Obviously every moving living thing can feel fear, that’s why they’re moving living things and that’s why they run away from predators
With a few exceptions like viruses, it’s pretty obvious. Rocks don’t make more rocks, nor does water
I’m not sure if scallops can run… But if you mean something like a mollusc, for example a snail, then I think it depends on which organism it is. I think a snail probably does feel fear yes in a very primal way. A bivalve like a scallop I’m not so sure, they have very basic nervous systems. An octopus I think is capable of fear and other more advanced emotions too, most likely. However, I think when we ascribe emotions to these animals we are anthropomorphising them. We have no way to know what their experience is like and we are sticking our human labels on them. Especially for a group such as molluscs, which diverged a very long time ago from the lineage that led to us. The feeling of fear, the understanding of danger and need to get away from it could be very primal and exist in many animals, but they may also feel it very differently to how we do. For example ants, I imagine a worker and does not feel fear for itself but rather the colony.
Unicellular organisms mostly move on the basis of concentration gradients, towards food and away from toxic things or predator signals. When one is struggling and being engulfed by a hydra or other unicellular organism, I don’t think it feels anything no. I think it is just trying to move away from the predator because it detects a molecular signal that it is “programmed” to move away from. By programmed I mean that behaviour is encoded in the complex interaction of the many systems that make it up, such as through the concerted action of it’s receptors, signalling pathways, enzymes, genes etc.
Rocks and water are not what I was talking about. Take for example cell-free translation systems. These are basically all of the contents of a cell but without any of the membranes. Like empty a cell into a (small) bucket. They still perform all of the biochemical reactions that took place in the normal cell. But they are not in a sack. There is no unified “thing” and it doesn’t move. If you did that to a paramecium, could that liquid still feel fear? It cant move away from anything. Is it alive? What makes something alive? Life is ultimately the sum of many complex biochemical reactions, but no one part of it is alive. Enzymes themselves are not alive surely. One single neuron is not alive.
If you had a human brain in a jar and, for arguments sake, it could still think as normal. It is intelligent and sentient, but it cannot replicate itself. But a virus, which is still much more simple than the brain in a jar, can. When you say that rocks don’t make more rocks, you seem to imply that the quality of life is in replication.
just youtube it, they can
and if they can do that, then of course they can feel fear too
wild
replace the hydra with a tiger and the amoeba with a deer, how is it any different apart from the number of cells? The deer prey could maybe have conscious thoughts/sorrow about its children during the last seconds of its life, but other than that the fear is fundamentally the same, it’s just more complex/scaled up
sure glad we don’t have any of those
Uh, I’m not an expert but I would suspect they’re in the process of dying if you do that. They just don’t die immediately, because nothing does (even a person who gets shot stays alive for a few minutes afterward). Can you feed this cell jelly its normal food and have it sustain itself like usual? If not then I would say it’s only alive on technicality, just like a person who’s been shot in the head and can still talk for the next few seconds–they’re technically also alive! But the person will die once the last few bits of brain oxygen run out due to the mechanical reality of their heart not beating, and the cell-jelly-in-a-bucket will also die after some time due to the mechanical reality of their vacuoles or whatever not being able to properly absorb food (I’m guessing, anyway. But this isn’t really relevant to the central point)
This is a disjoint coutnerexample, the point is not that a brain in a jar can’t replicate itself, but that the original organism that brain comes from, can. A man who gets a vasectomy is still alive, because his default state is being able to reproduce.
Rocks however, can NEVER reproduce. There is not A SINGLE rock that can reproduce. Therefore rocks are not alive.