Consciousness 1 – Zombies

Commuting days until retirement: 451

Commuting at this time of year, with the lengthening mornings and evenings, gives me a chance to lose myself in the sight of tracts of England sliding across my field of vision – I think of Philip Larkin in The Whitsun Weddings:  ‘An Odeon went past, a cooling tower, and someone running up to bowl…’  (His lines tend to jump into my mind like this). It’s tempting to enlarge a scene like this into a simile for life, like the one that Larkin’s poem leads into. Of course we are not just passive observers, but the notion of life as a film show – a series of scenes progressing past your eyes – has a certain curious attractiveness.

A rather more specatcular view than any I get on my train journey. Photo: Yamaguchi Yoshiaki. Wikimedia Commons

A rather more specatcular view than any I get on my train journey.
Photo: Yamaguchi Yoshiaki. Wikimedia Commons

Now imagine that, as I sit in the train, I am not quite a human being as you think of one. Instead I’m a cleverly constructed robot who appears in every way like a human but, being a robot, has something important missing. The objects outside the train form images on some sensor in each of my pseudo-eyes, and the results may then be processed by successive layers of digital circuitry which perform ever more sophisticated interpretative functions. Perhaps these resolve the light patterns that entered my ‘eyes’ into discrete objects, and and trigger motor functions which cause my head and eyes to swivel and follow them as they pass. Much, in fact, like the real me, idly watching the scenes sliding by.

Now let’s elaborate our robot to have capabilities beyond sitting on a train and following the objects outside; now it can produce all the behaviour that any human being can.This curious offspring of a thought-experiment is what philosophers refer to as a zombie – not the sort in horror films with the disintegrating face and staring eyeballs, but a creature who may be as well behaved and courteous as any decent human being. The only difference is that, despite (we presume) the brain churning away as busily as anyone else’s, there are no actual sensations in there – none of those primary, immediate experiences with a subjective quality: the fresh green of a spring day, or the inner rapture of an orgasm. So what’s different? There are a number of possibilities, but, as you will have guessed, the one I am thinking of is that inner, subjective world of experience we all have, but assume that machines do not. This is well expressed by saying that there’s something that it is like to be me, but not something that it’s like to be a machine.(1)  The behaviour is there all right, but that’s all. In the phrase I rather like, the lights are on but nobody’s at home.

Many people who think about the question nowadays, especially those of a scientific bent, tend to conclude that, of course, we must ultimately be nothing but machines of one sort or another. We have discovered many – perhaps most – of the physical principles upon which our brains and bodies work, and we have traced their evolution over time from simple molecular entities. So there we are – machines. But conscious machines – machines that there is something it is like to be? It has frequently been debated whether or not such a machine with all these capabilities would ipso facto be conscious – whether it would have a mind. Or, in other words, whether we could in principle build a conscious machine. (There are some who speculate that we may already have done so.)

One philosophical response to this problem is that of behaviourism, a now justly neglected philosophical position.(2) If you are a behaviourist you believe that your mind, and your mental activity – your thoughts – are defined in terms of your behaviour. The well-known Turing Test constitutes a behaviourist criterion, since it is based on the principle that a computer system whose responses are indistinguishable from those of a human is taken for all practical purposes to have a mind. (I wrote about Turing a little while ago – but here I part company with him.) And for a behaviourist, the phrase ‘What it is like to be…’ can have no meaning, or at best a rather convoluted one based on what we say or do; but its meaning is plain and obvious to you or me. It’s difficult to resist repeating the old joke about behaviourism: two post-coital behaviourists lie in bed together, and one says ‘That was great for you – how was it for me?’ But I take the view of behaviourism that the joke implies – it’s absurd.

Behaviourists, however, can’t be put down as burglars or voyeurs: they don’t peer into the lighted windows to see what’s going on inside. It’s enough for them that the lights are on. For them the concept of a zombie is either meaningless or a logical impossibility.  But there is another position on the nature of the mind which is much more popular in contemporary thought, but which has a different sort of problem with the notion of a zombie. I’m thinking of eliminative materialism.

Well, as I write this post, I feel it extending indefinitely as more ideas churn through that machine I refer to as my brain. So to avoid it becoming impossibly long, and taking another three weeks to write it, I’ll stop there, and just entitle this piece as Part 1. Part 2 will take up the topic of eliminative materialism.

In the meantime I’d just like to leave one thought: I started with a snatch of Philip Larkin, and I’ve always felt that poetry is in essence a celebration of conscious experience; without consciousness I don’t believe that poetry would be possible.


(1) The phrase is mainly associated with Thomas Nagel, and his influential 1974 paper What is it Like to be a Bat? But he in turn attributes it to the English philosopher Timothy Sprigge.

(2) I’m referring to the philosophical doctrine of behaviourism – distinct from, but related to the psychological one – J B Watson, B F Skinner et al.

Right Now

Commuting days until retirement: 491

Right now I am at home – another day off – waiting for some gravel to be delivered for our front drive. Right now, you are reading this (well I hope somebody is, or will). You can see I am having trouble with tenses here, because your ‘now’ is not my ‘now’. I know you are not reading this now, because I haven’t published it. But you know you are reading it now.

BlackboardThis all might seem a bit trivial and pointless, but stay with me for a bit. The notion I am circling around is the curious status of this concept of now. Let’s approach it another way: imagine yourself back at school, in a physics lesson. This may seem either an enticing or an entirely appalling prospect to you, but please indulge my little thought experiment. The teacher has chalked a diagram up on the blackboard (well, that was the cutting edge of presentation technology when I was at school). There’s the diagram up on the right. t1 and t2 obviously represent two instants of time for the ball, in its progress down the slope.

Somehow you are managing to stay awake, just. But in your semi-stupor you find yourself putting up your hand.

‘Yes?’, says the teacher irritably, wondering how there could be any serious question to be asked so far, and expecting something entirely facetious.

‘Er – which one is now?’ you ask. The teacher could perhaps consider your question carefully, for the sake any deep conceptual problem concealed within it, but instead she wonders why she bothered to get up this morning.

Not in the curriculum

Warwick University

Warwick University

However there is a serious philosophical issue here – admittedly not in the physics curriculum, to be fair to the teacher. And the reason it’s not in the curriculum is that the concept of ‘now’ is alien to physics. ‘Now’ is entirely confined to our subjective perception of the world. Think of the earth in its nascent state, a ball of molten lava and all that. Does it even make sense to imagine there was a ‘now’ then? We can say that this red-hot lava whirlpool formed before that one did – but we can’t say that either of them is forming now. Well of course not, in the obvious sense – it was four and a half billion years ago. But you could say that there was a time when your first day at school was ‘now’; and you can also say that there was a time when the execution of Marie Antoinette was ‘now’ – for somebody, that is, even perhaps for the unfortunate woman herself. But as for the formation of the earth – there was no one around for whom it could be a ‘now’. (Small green men excepted.)  You’re thinking of it as a ‘now’, I expect, but that’s because in your imagined scenario you are in fact there, as some sort of implicit presence suspended in space, viewing the proceedings.

It’s odd to try and visualise an exclusively objective world – one without a point of view – “The View from Nowhere” as the philosopher Thomas Nagel has put it; it’s the title of one of his books. In such a world there is no ‘now’, and therefore no past and no future, but only a ‘before’ and ‘after’ relative to any arbitrary point in time. And I was always struck by the way that T. S. Eliot, in Burnt Norton, from his Four Quartets, associates ‘time past and time future’ with the poetic and spiritual, and ‘time before and time after’ with the prosaic and mundane.

Language

Our language – indeed most languages – are built around the ‘now’, in that tenses correspond to past and future. Without the subjective sense of a ‘now’, language would surely work in a very different way. Interestingly, there is an example possibly relevant to this from the Pirahã people of the Amazon, who have been studied by the controversial linguist Daniel Everett. Their relationship to the passage of time seems to be different from ours – Everett claims that they have no real sense of history or of planning for the future, and so live in a kind of perpetual present. Correspondingly, inflections in their utterances are related not to temporal comparisons, like our tenses, but to the surrounding circumstances – e.g. whether something being described is right here, or is known first-hand, or has been reported by some other person. (Everett originally went to them as a Christian missionary, but was dismayed to find that they had no interest at all in Jesus unless Everett could claim to have met him.)

So all this would seem to support a philosopher I remember reading a long time ago. I don’t remember who he was, and can no longer find the passage. But I remember the sentence “Our language has a tiresome bias in favour of time.” I think this man was from the old-school style of linguistic philosophy, which held that most philosophical problems can be resolved into confusions caused by our use of language – and so time concepts were just another example of this. But I don’t think this is at all adequate as an approach, Pirahã or no Pirahã. However my language works, I would still have a sense of the differing character of past events, which cannot be changed, and future events, which mostly cannot be known – and of course a present, a now, which is the defining division between them. I would be surprised if the experience of a Pirahã person did not include that.

Space and time

How about another attack on the problem – to make an analogy between the spatial and the temporal? The spatial equivalent of ‘now’ is ‘here’. And there doesn’t seem to be any perplexity about that. ‘Here’ is where I am, er, now. Oh dear. Maybe these aren’t so easy to separate out. Perhaps ‘here’ seems simpler because we each have our own particular ‘here’. It’s where our body is, and that’s easily seen by others. And we can change it at will. But we all share the same ‘now’, and there’s not a lot we can do to change that. There is, of course, the remote possibility of relativistic time travel. I could in some sense change my ‘now’ relative to yours – but when I come back to earth I am back in the same predicament – just one that differs slightly in degree.

But do we all share the same ‘now’?  Here’s a slightly more disturbing thought. I have made out that my own sense of ‘now’ is confined to my own private experience, and doesn’t exist in the world ‘out there’. And the same is true of you, of course. I can see and hear you, and I find from your behaviour and the things you say that you are experiencing the the same, contemporaneous events that I am. But it’s not your private experience, or your ‘now’ that I am seeing – only your body. And your body – including of course your brain – is very much a part of the world ‘out there’. It’s only your private experience which isn’t, and I can’t experience that, by definition. So how do I know that your ‘now’ is the same as mine? Do we each float around in our own isolated time bubbles?

I think perhaps there is a solution of some sort to this. If your ‘now’ is different from mine, it must therefore be either before it or after it. Let’s suppose it’s an hour after. Then if my ‘now’ is at 4.30, yours is now at 5.30. But of course there’s a problem with the now that I have put in bold. It doesn’t refer to actual time, but to a sort of meta-time by which we mark out time itself. And how could this make sense? It’s rather like asking “how fast does time flow?” when there is no other secondary, or meta-time by which we could measure the ‘speed’ of normal time.

So perhaps this last idea crumbles into nonsense. But I still believe that, in the notion of ‘now’ there is a deep problem, which is one aspect of the more general mystery of consciousness. Do you agree? Most don’t.

But right now, the gravel is here, and is spread over the drive. So at least I’ve managed to do something more practical and down-to-earth today than write this post. And that’s a little bit of my past – or what is now my past – that I can be proud of.