The Hard Problem of physics

Is there a Hard Problem of physics that explains the Hard Problem of consciousness?

Hedda Hassel Mørch has a thoughtful piece in Nautilus’s interesting Consciousness issue (well worth a look generally) that raises this idea. What is the alleged Hard Problem of physics? She say it goes like this…

What is physical matter in and of itself, behind the mathematical structure described by physics?

To cut to the chase, Mørch proposes that things in themselves have a nature not touched by physics, and that nature is consciousness. This explains the original Hard Problem – we, like other things, just are by nature conscious; but because that consciousness is our inward essence rather than one of our physical properties, it is missed out in the scientific account.

I’m sympathetic to the idea that the original Hard Problem is about an aspect of the world that physics misses out, but according to me that aspect is just the reality of things. There may not, according to me, be much more that can usefully be said about it. Mørch, I think, takes two wrong turns. The first is to think that there are such things as things in themselves, apart from observable properties. The second is to think that if this were so, it would justify panpsychism, which is where she ends up.

Let’s start by looking at that Hard problem of physics.  Mørch suggests that physics is about the mathematical structure of reality, which is true enough, but the point here is that physics is also about observable properties; it’s nothing if not empirical. If things have a nature in themselves that cannot be detected directly or indirectly from observable properties, physics simply isn’t interested, because those things-in-themselves make no difference to any possible observation. No doubt some physicists would be inclined to denounce such unobservable items as absurd or vacuous, but properly speaking they are just outside the scope of physics, neither to be affirmed nor denied. It follows, I think, that this can’t be a Hard Problem of physics; it’s actually a Hard Problem of metaphysics.

This is awkward because we know that human consciousness does have physical manifestations that are readily amenable to physical investigation; all of our conscious behaviour, our speech and writing, for example. Our new Hard Problem (let’s call it the NHP) can’t help us with those; it is completely irrelevant to our physical behaviour and cannot give us any account of those manifestations of consciousness. That is puzzling and deeply problematic – but only in the same way as the old Hard Problem (OHP) – so perhaps we are on the right track after all?

The problem is that I don’t think the NHP helps us even on a metaphysical level. Since we can’t investigate the essential nature of things empirically, we can only know about it by pure reasoning; and I don’t know of any purely rational laws of metaphysics that tell us about it. Can the inward nature of things change? If so, what are the (pseudo-causal?) laws of intrinsic change that govern that process? If the inward nature doesn’t change, must we take everything to be essentially constant and eternal in itself? That Parmenidean changelessness would be particularly odd in entities we are relying on to explain the fleeting, evanescent business of subjective experience.

Of course Mørch and others who make a similar case don’t claim to present a set of a priori conclusions about their own nature; rather they suggest that the way we know about the essence of things is through direct experience. The inner nature of things is unknowable except in that one case where the thing whose inner nature is to be known is us. We know our own nature, at least. It’s intuitively appealing – but how do we know our own real nature? Why should being a thing bring knowledge of that thing? Just because we have an essential nature here’s no reason to suppose we are acquainted with that inner nature; again we seem to need some hefty metaphysics to explain this, which is actually lacking. All the other examples of knowledge I can think of are constructed, won through experience, not inherent. If we have to invent a new kind of knowledge to support the theory the foundations may be weak.

At the end of the day, the simplest and most parsimonious view, I think, is to say that things just are made up of their properties, with no essential nub besides. Leibniz’s Law tells us that that’s the nature of identity. To be sure, the list will include abstract properties as well as purely physical ones, but abstract properties that are amenable to empirical test, not ones that stand apart from any possible observation. Mørch disagrees:

Some have argued that there is nothing more to particles than their relations, but  intuition rebels at this claim. For there to be a relation, there must be two things being related. Otherwise, the relation is empty—a show that goes on without performers, or a castle constructed out of thin air.

I think the argument is rather that the properties of a particle relate to each other, while these groups of related properties relate in turn to other such groups. Groups don’t require a definitive member, and particles don’t require a single definitive essence. Indeed, since the particle’s essential self cannot determine any of its properties (or it could be brought within the pale of physics) it’s hard to see how it can have a defined relation to any of them and what role the particle-in-itself can play in Mørch’s relational show.

The second point where I think Mørch goes wrong is in the leap to panpsychism. The argument seems to be that the NHP requires non-structural stuff (which she likens to the hardware on which the software of the laws of physics runs – though I myself wouldn’t buy unstructured hardware); the OHP gives us the non-structural essence of conscious experience (of course conscious experience does have structure, but Mørch takes it that down there somewhere is the structureless ineffable something-it-is-like); why not assume that the latter is universal and fills the gap exposed by the NHP?

Well, because other matter exhibits no signs of consciousness, and because the fact that our essence is a conscious essence just wouldn’t warrant the assumption that all essences are conscious ones. Wouldn’t it be simpler to think that only the essences of outwardly conscious beings are conscious essences? This is quite apart from the many problems of panpsychism, which we’ve discussed before, and which Mørch fairly acknowledges.

So I’m not convinced, but the case is a bold and stimulating one and more persuasively argued than it may seem from my account. I applaud the aims and spirit of the expedition even though I may regret the direction it took.