I think the dividing line is deliberate communication - a dog barks because it "wants" to communicate. But then the counter-argument rejects the will, and comes down to "aren't all our actions because of basic chemistry?". I reject that assumption - not because there's a some sort of supernatural element, but just because a whole can be greater than the sum of its parts. There's a massive rift between "sun makes tree grow, preventing other trees from getting the light" and "I'm trying to sell my wares by expressing concepts of value, numbers, and desire".