But, however you want to configure these terms, what the Pirahã are doing in both of our examples is quintessential, textbook, bread-and-butter, vanilla-with-no-toppings metapragmatic discourse. It's talk about the efficacy of talk. That's all it needs to be. Nothing more, and nothing less.
And no animals ever notice or communicate about the fact that other species are communicating or sound funny? No cat has ever meowed because of a loud barking dog? When the definition is so broad, I'm not sure it's uniquely human.
As a less silly example, metapragmatics is what allows humans to expand language (by, say, introducing jargon like "metapragmatic" or "transformational grammar" in an academic paper) at a rate faster than generational evolution. In other words, metapragmatics does to a communication system what Turing completeness does to a computation engine. If that's not a big deal, I don't know what would be!
Another way to change language faster than generational evolution is simply creative language use. All that is required is some small flexibility in the system, and language can evolve within an individual. For example, I might coin a phrase like "pizzaslice" if for whatever reason I wanted a single concept to refer to "pizza slice"-- doing so is not necessarily metapragmatic, though. That may be a completely natural use of language (where performance influences competence!). In fact, this might be what we do every time we utter a new linguistic form based on our knowledge of our language.
Guijarro, I'm with you for most of your post. A few details:
(5) Human cognition is the ability to use formalised representations in lieu of real objects, events, etc out there, to do all sort of things with them.
Why don't other animals do this? Bees are a great example.
They may point to things out there, like we do, but hardly to things inside their minds (supposing we may describe their brains in that way, which is not at all clear to me).
Indeed-- I'm not sure we do that either. I think we merely articulate our perceptions of the world, and that animals do the same. Arguably a dog barking "cat" is expressing a mental state much beyond merely pointing out that there is a cat-- there's excitement as well.
(6) Humans may, then, communicate complex cognitive states with hardly or no external reference. They may use (or not) their language to help them in that task.
No reference? Doesn't your approach to language assume a truth-conditional semantics? If so, then that's all based on reference to truth and falsity.
I don't know what it would mean for humans to talk without any reference to the world.
I think what you mean is the general tendency for humans to talk beyond the "here and now" (with the exception of Pirahã, which is why I keep bringing it up). I see this as gradient rather than a strict dichotomy.
(7) What is different from other species, then, is not really that linguistic tool; but the faculty to communicate their representations. Other species may communicate their feelings, of course. But the representations of their feelings? ... I would be surprised if they could.
When a cat hisses, I think I know what it's feeling. It's not as articulate as a person, but I do believe that the cat is attempting to convey a message to the "listener" and expects the Cooperative Principle to be in effect.
(eight) True enough, however, our human linguistic tool has evolved in a very sophisticated way. Does that make it superior to other animal languages? Och, I do not ken! We will have to describe superiority as "more complex", if we wish to have that superiority feeling.
Indeed. And the problem then is that we
assume we are superior then look for the reason why. Unscientific, obviously. So... why all of the conclusions about language being a complex system and such? (It may very well to turn out to be the case, but at the moment it seems axiomatic rather than empirical.)
(9) It is true that humans have a greater power over the environment that other species, because we are able to amplify our mental representations by communicative processes and use them to engage in dealings with the world.
(10) This power will probably bugger up the world we now live in.
Is that a really evolutive advantage?
Indeed. But egocentrically it's "better", in the same sense that western technology may be viewed as "better" than the resources in other cultures. And therefore, we reach the (unfounded) conclusion that man is better / more complex than beast, and that man has a more complex and unique communication system. I remain skeptical.
The problem with complexity is that measuring it is complex. Without a specific way to operationalize the criteria, we don't have a single number. I know that 5<6, but without a way to measure two systems in a one-dimensional metric for complexity, we can't compare them in such a way. Certainly human communication is complex, but that doesn't necessarily lead to any more conclusions than just that simple observation. We don't know, for example, that humans have one more neural circuit (called Merge?) than animals. We don't know much at all.