I’d like to say a word for mystery. I think Haldane summed it up:

…the universe is not only queerer than we suppose, but queerer than we can suppose.

I hate that quote so much!  The complacent fake modesty; the characteristic Oxford attitude of mingled superiority and second-ratism:  don’t you go thinking you can apply your mind to these weighty issues, little man; the best you can do is listen reverently to the words of our mighty predecessors. Footnotes to Plato! Footnotes to Plato!

Good grief, what a reaction! Well, then, let me quote someone you ought to like better; Leibniz:

…it must be confessed that perception and that which depends upon it are inexplicable on mechanical grounds, that is to say, by means of figures and motions. And supposing there were a machine, so constructed as to think, feel, and have perception, it might be conceived as increased in size, while keeping the same proportions, so that one might go into it as into a mill. That being so, we should, on examining its interior, find only parts which push one another, and never anything by which to explain a perception.

It’s interesting, incidentally, that Leibniz should have picked a mill. In these days of computers, it’s natural for us to talk of thinking machines, but it must have been a much less obvious metaphor then; especially a mill, which doesn’t produce any very complex behaviour… though Babbage called the central processor of the Analytical Engine the ‘mill’ didn’t he… and of course Leibniz himself designed calculating machines, so perhaps a mechanical metaphor was more natural to him than it perhaps was to his readers… Anyway! The point is, this is a good example of a recurrent theme where someone holds up for our examination a mental phenomenon – in this case perception – and holds up as it were in the other hand the physical world, and says it’s just obvious that the latter cannot account for the former.

Here’s Brentano.

Every mental phenomenon is characterised by what the Scholastics of the Middle Ages called the intentional (or mental) inexistence of an object, and what we might call, though not wholly unambiguously, reference to a content, direction towards an object (which is not to be understood here as meaning a thing), or immanent objectivity. Every mental phenomenon includes something as object within itself, although they do not all do so in the same way. In presentation something is presented, in judgement something is affirmed or denied, in love loved, in hate hated, in desire desired and so on. This intentional in-existence is characteristic exclusively of mental phenomena. No physical phenomenon exhibits anything like it. We could, therefore, define mental phenomena by saying that they are those phenomena which contain an object intentionally within themselves.

This time we’re not talking about perception as such, but about intentionality: though Brentano claims it’s characteristic of every mental phenomenon.

Then again, Nagel.

If we acknowledge that a physical theory of mind must account for the subjective character of experience, we must admit that no presently available conception gives us a clue how this could be done. The problem is unique. If mental processes are indeed physical processes, then there is something it is like, intrinsically, to undergo certain physical processes. What it is for such a thing to be the case remains a mystery.

It would be easy to find similar sources in which people contrast the pinkish-grey jelly in the skull with the sparkling abstract mental life it apparently sustains. These claims tend to have two things in common. The first is, they are essentially ostensive. There isn’t really an argument being offered at this point, more a demonstration; we’re just being shown. Look at this; then look at that;  see?

Second, the claims are emphatic: they insist. It’s obvious, they say, just look: no-one could think that this was that.  These things have nothing whatever in common.

Of course they’re emphatic: they want to hurry us on past the sketchy part before we pause and ask why this shouldn’t be that. They’ve bundled the idea into its coat, thrust its hat into its hands, and are shoving it out the front door because they’re afraid that otherwise we might entertain it for a while.

If they didn’t want us to entertain the idea, why would they write about it? No. The absence of argument here isn’t a weakness; on the contrary, it’s a demonstration of the case. The very fact that we can’t give arguments for the existence of our mental life proves its utter distinctness; we can’t prove it, we can only notice it. But, and this is the reason for the emphasis, what noticing!  ‘In your face’ doesn’t begin to get it; phenomenal experience is inside your face; it’s so emphatically there you could fairly say it defines the word.  

What I’m saying is that these claims have a special quality; simply to pay careful attention to them is itself to experience their validity. The reality and distinctness of the mental world really deserve for once that much-misused term ‘self-evident’.

 It’s going to be very convenient if the absence of argument is taken to make a claim self-evident. Proving six impossible things before breakfast will be child’s play.

Actually, I think you are giving us an argument, but it’s so feeble you prefer it not to be recognised: the argument from bogglement. It runs: I can’t see how this could be that; it follows that it’s somehow cosmically distinct. The falsity of the argument, once stated is too obvious too require further comment, but let me just remind you of all those people who couldn’t imagine how the earth could possibly be moving.

Dennett has pointed out in a similar context that mysterians rely on passing off complexity as ineffability. Of course we don’t know all the details of how particular physical events in the world trigger neuronal events in the brain, let alone how that vastly complex series of functions constitutes experience. Even if we had the information, we couldn’t hold it all in mind at once. But our inability to do that, and any bogglement which may arise, does not in any way tend to show that there is no complete story.

Now Dennett would say that if only we could hold in mind all the details of the physical account, all this fantastically complex stuff, then the bogglement would vanish. But I’m not sure about that. Let me confess something: I too, boggle at the task of understanding the incomprehensible complexity of mental phenomena. But I boggle at other things too. Take computers. Now I think I can say without claiming to be an expert that I know how computers work.  I’ve played around with one or two high-level programming languages; I’ve dabbled in machine code; I’ve run up a couple of routines for imaginary Turing machines. In short, I know how it works. And yet, it still sometimes looks like magic; my mind still boggles sometimes at what I see computers doing. Now if I can get bogglement from something I understand quite well and know is a 100% physical process, it follows that my boggling at the brain and what it does shows nothing. 

It’s not the bogglement that matters; it’s the undeniable direct experience. It’s not because we don’t understand experience that we say it’s something distinctly non-physical; it’s because we can see it’s distinctly non-physical.  To me I confess it seems to need some kind of educated perversity to deny this. Colin McGinn has pointed out that conscious experience is non-spatial: it has no position or volume.  I don’t know quite what we should say about that – abstractions like numbers are non-spatial too in what seems a different sort of way (if I mention Plato, will you start shouting again?); but it captures something about the obvious – patent – irreducibility of the mental.

I mean, just give it fair consideration; lift your eyes out of that two-dimensional world you’re cycling round and round and just notice that there’s another whole aspect to the world. To think it possible is in this case to realise it’s true, I believe.

You know, you’re right.

You see it?

No, you’re right that with you there is no argument.