Restricted epistemic mysterianism

There are two forms of mysterianism about X (say, consciousness):

1. Conceptual: It would not be possible for us to even conceptualize the true theory of X.

2. Epistemic: It would not be possible for us to know the true theory of X.

Conceptual mysterianism about X entails epistemic mysterianism about X. In the case of typical Xs, like consciousness or intentionality or morality, epistemic mysterianism entails conceptual mysterianism. For if we could conceptualize the true theory of X, then God could reveal to us that that theory is true. (I restricted to “typical Xs”, for there are some truths that we could not know but which we could conceptualize. For instance, that the past existence of life on Mars is a reality unknown to me is something I can conceptualize, but I can’t possibly know it.)

However, one can weaken epistemic mysterianism to:

3. Restricted Epistemic: It would not be possible for us to know the true theory of X merely by human epistemic resources.

Consider the following interesting conditional:

4. If physicalism is true about consciousness, then restricted epistemic mysterianism is true about it.

Here is an argument against 4. Imagine that we find a new physics in the brains of precisely those organisms that it is plausible to think of as conscious (maybe cephalopods and higher vertebrates). For instance, maybe there is a new particle type that is only found in those brains, or perhaps some already known particle type behaves differently in those brains. Moreover, there is a close correlation between the behavior of the new physics and plausible things to say about consciousness in these critters. And when make a sophisticated enough AI, surprisingly that new physics also shows up in it. Given this, it would be reasonable to say that consciousness is to be identified with the behavior of that new physics.

But I think the following is true:

5. If physicalism is true about consciousness and there is no new physics in the brains of conscious beings, then restricted epistemic mysterianism is true.

Here’s why. Assume physicalism. Some degree of multiple realizability of consciousness is true since cephalopods and mammals are both conscious, even though our brains are quite different—assuming the “new physics in brains” hypothesis is false (if it were true, the structural differences between cephalopod and mammal brains could be relevantly outbalanced by the similarities with respect to the “new physics”). Multiple realizability requires that consciousness be abstracted to some degree from the particular details of its embodiment in us. But there is no way of knowing how far it is to be abstracted. And without knowing that, we won’t know the true theory of consciousness.

If this is right, the true view of mind must be found among these three:

• non-physicalism

• restricted epistemic mysterianism (with or without conceptual mysterianism)

• new physics.

On each of them, mind is mysterious. :-)

M-rays

Let me tell a story. Some neuroscientists detected a physically novel form of radiation, M-rays, that is emitted by brains of subjects who are thinking consciously. They discovered this much like X-rays were discovered, namely by finding something impinging on equipment in the lab in a way that could be explained by conventional physics. Further experiment showed that M-rays are not emitted by anything that clearly isn’t conscious. Moreover, the line between animals that emitted M-rays and animals that didn’t seemed to correspond to a noticeable difference in cognitive sophistication. Finally, in humans the M-rays turned out to be modulated in a way that has a natural one-to-one correspondence with the phenomenal states reported by the conscious subjects, so that the scientists eventually learned to discern from the M-rays what the subject’s conscious state is. (The CIA was very interested.)

In this case, it would be eminently reasonable for a physicalist to conclude that consciousness is the emission of M-rays.

This thought experiment shows that mysterians like Colin McGinn are mistaken in holding that no discovery we could make would solve the hard problem of consciousness.

But of course few physicalists actually expect to find a physically novel phenomenon in the brain.