You may already have seen Jochen’s essay Four Verses from the Daodejing, an entry in this year’s FQXi competition. It’s a thought-provoking piece, so here are a few of the ones it provoked in me. In general I think it features a mix of alarming and sound reasoning which leads to a true yet perplexing conclusion.

In brief Jochen suggests that we apprehend the world only through models; in fact our minds deal only with these models. Modelling and computation are in essence the same. However, the connection between model and world is non-computable (or we face an infinite regress). The connection is therefore opaque to our minds and inexpressible. Why not, then, identify it with that other inexpressible element of cognition, qualia? So qualia turn out to be the things that incomprehensibly link our mental models with the real world. When Mary sees red for the first time, she does learn a new, non-physical fact, namely what the connection between her mental model and real red is. (I’d have to say that as something she can’t understand or express, it’s a weird kind of knowledge, but so be it.)

I think to talk of modelling so generally is misleading, though Jochen’s definition is itself broadly framed, which means I can’t say he’s wrong. In his terms it seems anything that uses data about the structure and causal functioning of X to make predictions about its behaviour would be a model. If you look at it that way, it’s true that virtually all our cognition is modelling. But to me a model leads us to think of something more comprehensive and enduring than we ought. In my mind at least, it conjures up a sort of model village or homunculus, when what’s really going on is something more fragmentary and ephemeral, with the brain lashing up a ‘model’ of my going to the shop for bread just now and then discarding it in favour of something different. I’d argue that we can’t have comprehensive all-purpose models of ourselves (or anything) because models only ever model features relevant to a particular purpose or set of circumstances. If a model reproduced all my features it would in fact be me (by Leibniz’ Law) and anyway the list of potentially relevant features goes on for ever.

The other thing I don’t like about liberal use of modelling is that it makes us vulnerable to the view that we only experience the model, not the world. People have often thought things like this, but to me it’s almost like the idea we never see distant planets, only telescope lenses.

Could qualia be the connection between model and world? It’s a clever idea, one of those that turn out on reflection to not be vulnerable to many of the counterarguments that first spring to mind. My main problem is that it doesn’t seem right phenomenologically. Arguments from one’s own perception of phenomenology are inherently weak, but then we are sort of relying on phenomenology for our belief (if any) in qualia in the first place. A red quale doesn’t seem like a connection, more like a property of the red thing; I’m not clear why or how I would be aware of this connection at all.

However, I think Jochen’s final conclusion is both poignant and broadly true. He suggests that models can have fundamental aspects, the ones that define their essential functions – but the world is not under a similar obligation. It follows that there are no fundamentals about the world as a whole.

I think that’s very likely true, and I’d make a very similar kind of argument in terms of explanation. There are no comprehensive explanations. Take a carrot. I can explain its nutritional and culinary properties, its biology, its metaphorical use as a motivator, its supposed status as the favourite foodstuff of rabbits, and lots of other aspects; but there is no total explanation that will account for every property I can come up with; in the end there is only the carrot. A demand for an explanation of the entire world is automatically a demand for just the kind of total explanation that cannot exist.

Although I believe this, I find it hard to accept; it leaves my mind with an unscratched itch. If we can’t explain the world, how can we assimilate it? Through contemplation? Perhaps that would have been what Laozi would have advocated. More likely he would have told us to get on with ordinary life. Stop thinking, and end your problems!