That's a great point. All layers are correct, but most won't be useful for a given problem.
If you're thinking about, say, crowd reactions, then you don't want the "meatbag" model. Instead, you need a higher-level psychological model. However, if your problem is "what kind of injuries result from a bomb", then the "meatbag" model is right on.
Thinking of the body as a loose confederation of fundamental particles is fairly useless when trying to decide how much to charge for a product, but it's an excellent model when e.g. figuring out how much radiation a person will absorb from a source.
No layer denies the usefulness or reality of any of the others.
If you're thinking about, say, crowd reactions, then you don't want the "meatbag" model. Instead, you need a higher-level psychological model. However, if your problem is "what kind of injuries result from a bomb", then the "meatbag" model is right on.
Thinking of the body as a loose confederation of fundamental particles is fairly useless when trying to decide how much to charge for a product, but it's an excellent model when e.g. figuring out how much radiation a person will absorb from a source.
No layer denies the usefulness or reality of any of the others.