>I'd argue 'concepts are analogous to shape/weight/attraction.
I can see how physical things can have causal influence over other physical things by way of their shape/weight/attraction. Those are just physical properties. What I'm having a hard time seeing is how a mental state can have causal influence over something physical, not merely by virtue of its tangible third person properties (e.g. size, weight, charge, etc.), but by virtue of its semantic content, i.e. what it is about. It could be that I'm not explaining myself very clearly.
Take my desire to eat ice cream. Allegedly, this desire has physical properties that can be expressed in teh language of physics and chemistry. There's a certain brain structure associated with that desire. It seems to me it's that brain structure and all its third person properties that affect my behavior, causing me to get up and get some ice cream. But how is it that the felt experience of wanting the ice cream affect my behavior by virtue of the first person subjective experience of it? Do you know what I mean?
Suppose, hypothetically, that there's some physical structure in my brain, some configuration of molecules, neurons, chemical reactions, etc. that cause me to get up and fetch some ice cream. How or why does it matter what the subjective experience associated with that physical structure is? Couldn't it be just anything? If it happened to be associated with the thought that triangles are not circles or that George is a nice name, but it still had the same underlying physical structure, wouldn't it still result in me getting up to get some ice cream?
Do you see what I'm asking? How do our mental states, by virtue of their "aboutness' or "intentionality," affect our behavior? Or does it?