When you look at non-human animal communication, for instance birds and cats, you can explain what's going on simply in terms of cause and effect. Now, human language is more complex, but if you happen to have determinist beliefs, at some level you believe it's all cause and effect, right? So, when describing why and how people use words, would an ideal observer need to talk about the meanings of words at all, or would the concept of meaning drop out as unnecessary?

Since no one else has answered your question, I'll chime in. I confess that I find it hard to see how any explanation of human communication purely at the level of (say) sounds and scribbles, with no reference to the meaning conveyed by sounds and scribbles, could avoid leaving out something important. But I'm no expert on this topic, so all I can do is recommend reading the SEP entry on "Eliminative Materialism," found here. I'm going to read it now myself.

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