Sentio Ergo Sum: Why Qualia Can't Be Reduced to a Vocabulary Problem

Context

This started as a conversation between friends about consciousness, and whether the word even means anything beyond a convenient label.

One friend argued a position close to Wittgenstein's deflationism: "consciousness" is a concept we created for humans, useful because we experience it, but possibly meaningless beyond that. For him, asking "is X conscious?" is really two questions: first, does the concept of consciousness even apply to X? And second, is X conscious? The second question only makes sense if the first one does. And the first one is ultimately a semantic question, like asking whether a "bunch of apples" is a thing. Without enough agreed-upon examples of conscious entities (we really only have one: humans), we can't even share a common notion of what consciousness means.

Another friend pushed back from a philosophy of science angle: yes, language is fuzzy by design, but the role of philosophy and science is precisely to put precise words on phenomena. He pointed to the distinction between psychological consciousness (being responsible for one's actions) and phenomenal consciousness (the sensation of what it's like). The real debates are about the latter, and competing definitions make it messy.

What follows is my attempt to argue that qualia, the felt quality of experience, is not just a vocabulary problem but points to something irreducible that resists both deflationary and purely materialist explanations.

Argument

This attempt to reduce it to merely a matter of vocabulary where some words find consensus and others struggle to find a proper meaning. So I'll modestly attempt to define the one I'm talking about from my side.

I'm talking about what results from my experience, the specific quality of the elements that constitute consciousness. I'll come back to this.

What I'm not talking about: I'm not talking about an ability to self-reference or to express or acknowledge a certain subjectivity, although this ability to acknowledge is necessary to speak about the experience itself: Qualia.

If we accept the hypothesis that language is a tool of communication between individuals bearing a utility in describing our condition and our desires, then we cannot deny that the notion of Qualia, the quality of lived experience, must come from somewhere. Where from?

One could trace this intuition back to Descartes (if not well before). In radical doubt, he searches for what holds up when everything is doubted: the senses, the external world, even mathematics. What remains is the experience of doubt itself, the famous "I think therefore I am". One could almost say: I feel therefore I am, Sentio ergo sum. For it is neither a syllogism nor a logical argument, it is an observation he makes: something is experiencing doubt, and that cannot itself be doubted. What is interesting for our discussion is that Descartes does not prove what consciousness is or the quality of that consciousness, he shows that there is an irreducible residue of experience that cannot be dissolved into an objective description of the world.

But even if we stick to pure materialism, we can only observe that the apprehension of the world's events (consciousness) is merely a contingent observation of an execution that seems determined. Within this determinism it seems coherent to conceive of consciousness as a link in a causal chain gathering information within a complex system. But it seems less obvious to understand the implication of the quality of that experience. What role does Qualia play? The felt sense of that experience?

Take pain. The information of pain has a useful causal role in the decision-making process: I touch fire, the signal travels up, I pull my hand away. A materialist would say that the feeling of pain IS that information, that there is nothing "extra". But then why does it feel like something to suffer? A system processing the exact same information without feeling anything would perform the exact same withdrawal (philosophical zombie). The quality of that pain, which appears to us beyond any possible doubt, does not seem to play an additional functional role, and yet it is there. The problem isn't explaining what consciousness does, but explaining why there is a "something it's like".

This is where I come back to the vocabulary argument. Saying that "consciousness" is just a fuzzy word for which we don't have enough examples to pin down the meaning is a defensible position for consciousness in the functional sense (information processing, self-reference, etc.). But for qualia, the argument goes in circles: you can't say "this word doesn't refer to anything precise" when each of us knows exactly what it's like to see red or feel a burn. The problem isn't that the concept is fuzzy, it's that it's private, and that is precisely why it resists formalisation.

As a bonus I'd even like to take the reflection further and say that the very existence of the word Qualia arose from the need of individuals to express a quality of being independent from the conscious mechanisms at work, so much so that: It would be the ultimate test to determine whether an AI is sentient. Deprived of any prior knowledge of this word (and therefore a different training from today's), and endowed with an ability to develop language on its own, if it nonetheless ends up speaking about the specific quality of its own experience then it is undoubtedly sentient.

@Hubert L. Dreyfus @René Descartes @Baruch Spinoza @Augustine of Hippo @Edmund Husserl