I’m certain your model of what purpose is is a lot more detailed than mine. My take, however, is that animal brains don’t exactly have a utility function, but probably do have something functionally similar to a reward function in machine learning. A well-defined set of instrumental goals terminating in terminal goals would be a very effective way of maximizing that reward, so the behaviors reinforced will often converge on an approximation of that structure. However, the biological learning algorithm is very bad at consistently finding the structure, and so the approximations will tend to shift around and conflict a lot- behaviors that approximate a terminal goal one year might approximate an instrumental goal later on, or cease to approximate any goal at all. Imagine a primitive image diffusion model with a training set of face photos- you run it on a set of random pixels, and it starts producing eyes and mouths and so on in random places, then gradually shifts those around into a slightly more coherent image as the remaining noise decreases.
So, instrumental and terminal goals in my model aren’t so much things agents actually have as a sort of logical structure that influences how our behaviors develop. It’s sort of like the structure of “if A implies B which implies C, then A implies C”- that’s something that exists prior to us, but we tend to adopt behaviors approximating it because doing so produces a lot of reward. Note, though, that comparing the structure of goals to logic can be confusing, since logic can help promote terminal goals- so when we’re approximating having goals, we want to be logical, but we have no reason to want to have terminal goals. That just something our biological reward function tends to reinforce.
Regarding my use of the term “category error”, I used that term rather than saying “terminal goals don’t require justification” because, while technically accurate, the use of the word “require” there sounds very strange to me. To “require” something means that it’s necessary to promote some terminal goal. So, the phrase reads to me a bit like “a king is the rank which doesn’t follow the king’s orders”- accurate, technically, but odd. More sensible to say instead that following the king’s orders is something having to do with subjects, and a category error when applied to a king.
I’m certain your model of what purpose is is a lot more detailed than mine. My take, however, is that animal brains don’t exactly have a utility function, but probably do have something functionally similar to a reward function in machine learning. A well-defined set of instrumental goals terminating in terminal goals would be a very effective way of maximizing that reward, so the behaviors reinforced will often converge on an approximation of that structure. However, the biological learning algorithm is very bad at consistently finding the structure, and so the approximations will tend to shift around and conflict a lot- behaviors that approximate a terminal goal one year might approximate an instrumental goal later on, or cease to approximate any goal at all. Imagine a primitive image diffusion model with a training set of face photos- you run it on a set of random pixels, and it starts producing eyes and mouths and so on in random places, then gradually shifts those around into a slightly more coherent image as the remaining noise decreases.
So, instrumental and terminal goals in my model aren’t so much things agents actually have as a sort of logical structure that influences how our behaviors develop. It’s sort of like the structure of “if A implies B which implies C, then A implies C”- that’s something that exists prior to us, but we tend to adopt behaviors approximating it because doing so produces a lot of reward. Note, though, that comparing the structure of goals to logic can be confusing, since logic can help promote terminal goals- so when we’re approximating having goals, we want to be logical, but we have no reason to want to have terminal goals. That just something our biological reward function tends to reinforce.
Regarding my use of the term “category error”, I used that term rather than saying “terminal goals don’t require justification” because, while technically accurate, the use of the word “require” there sounds very strange to me. To “require” something means that it’s necessary to promote some terminal goal. So, the phrase reads to me a bit like “a king is the rank which doesn’t follow the king’s orders”- accurate, technically, but odd. More sensible to say instead that following the king’s orders is something having to do with subjects, and a category error when applied to a king.