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The most common argument against insects feeling pain used to be that they lacked the nociceptors (sensory neurons that respond to stimuli indicating damage) th

by quasque 13y ago

The most common argument against insects feeling pain used to be that they lacked the nociceptors (sensory neurons that respond to stimuli indicating damage) that provide pain perception in humans, and by analogy other vertebrates. However, it turns out that fruit fly larvae have thermal nociceptors that respond at the same threshold (~42°C) as those in vertebrates, rather damaging that line of argument. Alternatively, we could state that they don't have the mental capacity to experience pain as a conscious human might, but this is difficult (maybe impossible) to prove: how can we objectively measure what is essentially a private, subjective experience? This also suggests that the conceptual line drawn between vertebrate animals and other living things regarding which species can experience pain, is really quite arbitrary.

canjobear 13y ago
> how can we objectively measure what is essentially a private, subjective experience? We can't measure "subjective experience", nor can we verify that it even exists; which suggests that it is not a well-defined concept and we shouldn't be using it for anything.
- 1457389 13y ago
  Many of the most important concepts in science, not to mention ethics, are not yet well defined... I don't think your stance here is very productive.
- quasque 13y ago
  From a philosophical point of view you may well be correct. However, there is the option of using behavioural observations as a surrogate. For example, exposing living things to pain stimuli and analogising the response to what we humans know to be a typical reaction to pain. This does carry the risk of inappropriately anthropomorphising non-human species, but as the question of whether other creatures feel pain is intimately linked to the morality of how humans should treat them (after all, we're not going to be able to stop other animals from inflicting pain on each other), then maybe it's not a problem.
  - aaronem 13y ago
    I have a microcontroller, a tiny DC motor, a pair of wheels, and a handful of thermistors. From these I build a robot, autonomous to the limit of its battery charge, which senses the temperature of its surroundings and acts on this information to move itself toward temperatures within a range its programming defines as preferable. The speed with which it does so is determined, to the limit of the motor's capability, by the difference between the temperature it's moving away from, and the temperature it's moving toward. If I use a cigarette lighter or a lit match to apply an open flame to one of this robot's thermistors, it will flinch away from the stimulus as fast as it can. This is closely analogous to "what we humans know to be a typical reaction to pain"; if you applied the same stimulus to one of my fingers, after all, I would initially react in much the same fashion. From this behavioral observation, do you conclude that my robot's subjective experience a) exists at all, and b) encompasses the experience of pain? Does this behavioral observation inform your concept of the morality surrounding how this robot is treated by humans? Why, or why not?
    - gordonguthrie 13y ago
      ... but your robot isn't delicious...
      - aaronem 13y ago
        Not to us, because we don't eat rocks and metal. If there's a planet out there whose apex predator species is silicaceous in the same way we're carbonaceous, then, there, my robot is halfway to being a cricket, and is probably quite tasty when properly prepared. (I eagerly invite speculation on what, on our notional silicaceous Earth-analog, might constitute a parallel to veganism.)
        gordonguthrie 13y ago
        Only eating Apple. Drrump, tissch!
        13y ago
1457389 13y ago
My stance as a vegan is that it is best to err on the side of assuming they do experience some form of subjective reality that probably includes pain. Most insects possess ganglia that integrate and process sensory information, and I would argue that the very process of integrating this information implies that a subjective representation of reality is being created at some level. Pain is a fundamentally important signal for complex organisms; I would really be very surprised if insects did not have some way to detect noxious stimuli. >the conceptual line drawn between vertebrate animals and other living things regarding which species can experience pain, is really quite arbitrary. It absolutely is. Right there in the name it is clear that we are mostly divided due to the ease of identifying certain anatomical structures. The way we categorize more complex forms of life is flawed in that it doesn't properly reflect convergently evolved functions. With more 'simple' forms of life like bacteria we get it right in that we more often sort by functionality: methane producing, carbon fixing, anaerobic, aerobic, etc.
- judk 13y ago
  Plants are also known to detect and respond to noxious stimuli. Now what?
  - aaronem 13y ago
    Good question! The impression I have is that we all, vegans included, draw a line somewhere, and that there's almost never any solid reasoning behind anyone's decision on how to circumscribe his diet. I'd be really interested to hear an avowed vegan explain why it's not okay to kill and eat animals which are capable of nociception, but okay to kill and eat plants which are also so capable.
    - 1457389 13y ago
      Nociception implies that the raw sensory data is being processed or encoded in some way. This can't happen without a nervous system. Plants don't have a nervous system, ergo, nociception is not occurring. I am quite convinced that this is consistent with our current understanding of the biology, but would be happy to learn differently. Another way to approach this ethical dilemma is to proceed from a position of harm minimisation. When you consider energy inputs required to generate plant based calories versus animal based calories, the former is just about always more efficient. To the extent that we consider the moral harm of animal suffering greater or equal to plant suffering, if it exists, we must tend to substitute to plant-based calories to minimise the total suffering we inflict on other life.

by quasque 13y ago

canjobear 13y ago

> how can we objectively measure what is essentially a private, subjective experience? We can't measure "subjective experience", nor can we verify that it even exists; which suggests that it is not a well-defined concept and we shouldn't be using it for anything.

1457389 13y ago
Many of the most important concepts in science, not to mention ethics, are not yet well defined... I don't think your stance here is very productive.
quasque 13y ago
From a philosophical point of view you may well be correct. However, there is the option of using behavioural observations as a surrogate. For example, exposing living things to pain stimuli and analogising the response to what we humans know to be a typical reaction to pain. This does carry the risk of inappropriately anthropomorphising non-human species, but as the question of whether other creatures feel pain is intimately linked to the morality of how humans should treat them (after all, we're not going to be able to stop other animals from inflicting pain on each other), then maybe it's not a problem.
- aaronem 13y ago
  I have a microcontroller, a tiny DC motor, a pair of wheels, and a handful of thermistors. From these I build a robot, autonomous to the limit of its battery charge, which senses the temperature of its surroundings and acts on this information to move itself toward temperatures within a range its programming defines as preferable. The speed with which it does so is determined, to the limit of the motor's capability, by the difference between the temperature it's moving away from, and the temperature it's moving toward. If I use a cigarette lighter or a lit match to apply an open flame to one of this robot's thermistors, it will flinch away from the stimulus as fast as it can. This is closely analogous to "what we humans know to be a typical reaction to pain"; if you applied the same stimulus to one of my fingers, after all, I would initially react in much the same fashion. From this behavioral observation, do you conclude that my robot's subjective experience a) exists at all, and b) encompasses the experience of pain? Does this behavioral observation inform your concept of the morality surrounding how this robot is treated by humans? Why, or why not?
  - gordonguthrie 13y ago
    ... but your robot isn't delicious...
    - aaronem 13y ago
      Not to us, because we don't eat rocks and metal. If there's a planet out there whose apex predator species is silicaceous in the same way we're carbonaceous, then, there, my robot is halfway to being a cricket, and is probably quite tasty when properly prepared. (I eagerly invite speculation on what, on our notional silicaceous Earth-analog, might constitute a parallel to veganism.)
      - gordonguthrie 13y ago
        Only eating Apple. Drrump, tissch!
        13y ago

1457389 13y ago

My stance as a vegan is that it is best to err on the side of assuming they do experience some form of subjective reality that probably includes pain. Most insects possess ganglia that integrate and process sensory information, and I would argue that the very process of integrating this information implies that a subjective representation of reality is being created at some level. Pain is a fundamentally important signal for complex organisms; I would really be very surprised if insects did not have some way to detect noxious stimuli. >the conceptual line drawn between vertebrate animals and other living things regarding which species can experience pain, is really quite arbitrary. It absolutely is. Right there in the name it is clear that we are mostly divided due to the ease of identifying certain anatomical structures. The way we categorize more complex forms of life is flawed in that it doesn't properly reflect convergently evolved functions. With more 'simple' forms of life like bacteria we get it right in that we more often sort by functionality: methane producing, carbon fixing, anaerobic, aerobic, etc.

judk 13y ago
Plants are also known to detect and respond to noxious stimuli. Now what?
- aaronem 13y ago
  Good question! The impression I have is that we all, vegans included, draw a line somewhere, and that there's almost never any solid reasoning behind anyone's decision on how to circumscribe his diet. I'd be really interested to hear an avowed vegan explain why it's not okay to kill and eat animals which are capable of nociception, but okay to kill and eat plants which are also so capable.
  - 1457389 13y ago
    Nociception implies that the raw sensory data is being processed or encoded in some way. This can't happen without a nervous system. Plants don't have a nervous system, ergo, nociception is not occurring. I am quite convinced that this is consistent with our current understanding of the biology, but would be happy to learn differently. Another way to approach this ethical dilemma is to proceed from a position of harm minimisation. When you consider energy inputs required to generate plant based calories versus animal based calories, the former is just about always more efficient. To the extent that we consider the moral harm of animal suffering greater or equal to plant suffering, if it exists, we must tend to substitute to plant-based calories to minimise the total suffering we inflict on other life.