Introducing mephistos

Ich bin der Geist, der stets verneint!
— J. W. Goethe, Faust I, 1338

Zombies are not conscious but believe they are. They are as tempted as we are to believe that their experiences possess nonphysical qualitative properties, but they are wrong. I want to introduce another class of creatures, who are conscious but don’t believe they are. They are consciousness deniers. As a nod to the denying spirit depicted by Goethe, I’ll call them mephistos. Let me tell you a little about them.

Mephistos are conscious in just the way we are. Their brains are like ours and they inhabit a world like ours, with the same physical laws, the same psycho-physical laws (if there are any), and the same quiddities (if there are any). So if our experiences possess nonphysical qualitative properties, then theirs do too.

However, mephistos don’t conceptualize their consciousness in the way we do, as involving acquaintance with private mental qualities. Though every bit as reflective and self-aware as us, they don’t think of themselves as having a phenomenal inner world. If you ask them to describe what their experience is like, they tell you about the world, rhapsodizing about the vibrant red of ripe strawberries, the rich texture of velvet, the smokiness of dark roast coffee, and so on. They think of these as sensible qualities belonging to external objects or parts of their bodies, not as sensory qualities belonging to their minds.

Of course, mephistos know that their senses sometimes mislead them about the world. They dream and hallucinate and are subject to perceptual illusions just like us. But they don’t think of these episodes as demonstrating the existence of an internal world. When asked what happened, they just shrug and say that their senses lied. They thought they were aware of something, but they were wrong. They aren’t inclined to say that they really were aware of something mental.

If you point out that objects look different under different viewing conditions, mephistos generally deny it, either saying that their senses misled them or insisting that the objects in question didn’t look different at all. The tomato still looked red in the dim light, they say, just as a high tower still looks tall when seen from a great distance.

Mephisto philosophers and scientists do not think there is a hard problem of consciousness. Consciousness, they believe, is an immensely complex set of informational and control processes, all of which can, in principle, be reductively explained. Many have, however, argued that there is a hard problem of sensible qualities — the problem of explaining how surface textures give rise to colours, how molecules give rise to tastes, how pressure waves give rise to sounds, and so on. This problem has generated a lot of metaphysical speculation among mephisito scholars. (If you’re interested in their theories, have a look at this paper by the philosopher Alex Byrne, who has made a study of them.)

Today, however, a growing band of radical mephisto philosophers argue that this hard problem is misconceived. Sensible qualities, they argue, are illusory, and philosophers should turn aside from metaphysical speculation and focus on explaining how and why the brain produces the conviction that they exist.

So these are the mephistos. Their situation is just like ours, but they conceptualize it very differently. Is it we or they who are getting things wrong? And if there is any doubt, how can we be certain that the existence of phenomenal consciousness is a datum?

The last word about Mary

What happens when Mary leaves her black-and-white room and has a red colour experience for the first time? Here’s the answer, in outline. (I’ll assume for the sake of argument that Mary has developed the neural circuitry required for colour vision.)

  1. Mary’s visual system begins tracking something red, generating a huge set of active, interconnected first-order informational states, which in turn generate a vast range of reactions and reactive dispositions. Call complex of first-order informational and reactive states R1.
  2. Mary’s introspective system begins tracking the states in R1, generating a huge set of active, interconnected second-order informational states, which in turn generate a vast range of reactions and reactive dispositions. Call this complex of higher-order informational and reactive states R2.

  3. Mary has never instantiated R1 and R2 before and there was no practicable way to induce them in her pre-release.

  4. The informational states in R1 and R2 carry a mass of information about the world and about Mary’s current state.

  5. None of this information is about anything essentially private and non-physical (in the structure/dynamics sense). The informational states involved were generated by tracking physical features which could also be tracked by suitable scientific instruments and which were fully described in Mary’s textbooks.

  6. Mary’s total informational situation is novel. She has not previously instantiated this combination of active, interconnected informational states, and there was no practicable way she could have done so pre-release.

That’s it. (5) preserves physicalism, while (6) accounts for the intuition that Mary enters a new knowledge state. Fill in the details with your preferred theories of perception, introspection, and so on.

There’s no more to say ;)