When a friend accidentally burns themselves on a stove-top, their pain is usually very obvious – cursing, gesturing wildly, and even the explicit verbal pronouncement of "I am in pain." It's also very clear from this display that their pain is viewed as a "bad" thing – they want it to stop, they will be more vigilant in the future to prevent it from happening again, and they very likely either want or even expect you to help out in these endeavors. Pain, while being a survival affirming biological phenomena, is (at least in this simple case here) also inherently ethical.
We can then imagine that this same friend's nervous system might be manipulated (whether through
mutation, injury, or pharmacological manipulation) to prevent them from feeling pain. While we might initially be shocked at such a turn of events, we could be convinced of such a change if our friend stopped responding to usually painful stimuli (such as our villain the stove-top) with the same clear "pained" reaction. So changing the nervous system clearly changes whether or not the individual can feel pain, leading us to believe that pain is something the brain does.
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| Pain is something the brain does- but how do we know when it is doing it? Image from here. |
However, in addition to our verbal friend, there are an untold number of animals, (including
other types of humans), plants, virions, rocks,
alien beings, artificial intelligences, puppets, and tissue cultures whose internal states aren't as readily apparent. Whether it is that they can't talk (as in the case of the bulk of that list) or we suspect that their speech might not be truthful (as in the case of artificial intelligences or puppets), we must rely on other, perhaps subtler methods of inferring their internal state. Holding off on the very important question of how we
should evaluate a creature's pain, let us instead focus on evaluating how we
currently determine if a strange being is in pain or not. To simplify the problem significantly, let's focus on how this process occurs in the present day United States. While even in this limited scope we see substantial debate over
what counts as pain in
non-human animals, there is at least one place where some sort of official, if temporary, compromise is forced into existence: animal cruelty law. Can US animal cruelty laws provide a formal definition for how Americans think of pain?