31 March 2014

If I Only had a Brain

If I only had a brain I would not be conversing or consulting with anything. The flowers would wait in vain for my dulcet repartee; the rain would be forced to seek managerial guidance elsewhere.

It is opportunistic of me to seize upon the jumbled syntax of the title of the song from The Wizard of Oz, and I know it scans better that way, but I have reasons to do so. My rediscovery of the song coincided with a time when I was writing an essay on the subject of personal identity, specifically on its indeterminacy. And – in connection with that – I was delving again into Daniel Dennett’s ‘zombie’ thought experiments. It occurred to me that the Scarecrow – a character for whom I have some fellow feeling – could be a useful metaphor in that regard, not only because he is a brainless zombie but also because the title of the song seems to suggest that he wishes to be the polar opposite. And what is that? Why, a disembodied brain! Oh, my!

What the Scarecrow really wants is to be whole. He wants the complete set – a body and a brain. He can carry a tune, but he doesn’t think he can carry any thoughts, and that is a source of some distress for him. He is a zombie that knows he’s a zombie, so just what kind of zombie does that make him? Perhaps it makes him what Dennett called a ‘zimbo’:
A zimbo is a zombie that, as a result of self-monitoring, has internal (but unconscious) higher-order informational states that are about its other, lower-order informational states.i
The Scarecrow clearly has self-monitoring enough to inform himself that he doesn’t have a brain, but if he can’t really carry any higher-order informational states (due to his lack of a brain) then maybe he is merely a zombie, not a zimbo.

Meanwhile – in my version of this tale – the Scarecrow’s brain awaits him in a vat of cerebrospinal fluid, at the Wizard’s lab. The Wizard knows that the Scarecrow is coming to collect it, because wires implanted into the brain produce a display of the brain’s thoughts, which the Wizard can then read. How could the brain know that the Scarecrow is coming? Is it telepathic? No. It knows the Scarecrow is coming, because it is the scarecrow that’s coming.

The cruel Wizard wished to perform an experiment to do with location of ‘self’. So he removed a man’s brain and placed it in a vat; he altered the brain’s memories so that it thought it was a scarecrow; then he connected the brain-in-the-vat wirelessly to the man’s body. After the encephalectomy operation, he dressed up the brainless body in ragged clothes stuffed with straw, and then staked it out in a field near the yellow brick road.

The scarecrow man wakes up in the field, beset by crows, knowing that he has no brain but not knowing that he was ever anything but a scarecrow. A girl with a dog frees him from his stake and tells him that a great wizard will give him a brain, if he goes along with her. This seems an attractive proposition. Given the circumstances, Dorothy believes that the man is a scarecrow. And the brain-in-the-vat’s perception of its remote body has been altered so that it sees only straw, even upon detailed self-examination of its body.

We now understand the great mystery of how the brainless Scarecrow could walk, dance, sing, and even hold a conversation: he could do all those things because he actually had a brain all along; it just wasn’t in his body.

Your brain is located in your skull, but that does not mean that you are located there. Your senses – such as vision, touch, and hearing – inform you of the position of your body in relation to other things and people; your sense of proprioception tells you the position of your limbs in space. That is all. If we were to stretch your complete sensorium out over many miles, then you would be gigantic. You might argue that, under those circumstances, you would only feel gigantic, but why should that be the case? You feel that you are the size you are only because your senses provide you with that information. If your senses were different, you would be different. As we don’t know where we, as selves, are located – indeed we have no evidence that we are anywhere – we have this potential adaptability and zoomability.

So we are not so different from our unfortunate friend the Scarecrow. When he eventually encounters his brain in the vat, behind the Wizard’s screen, the Wizard restores his memory of being a man. Does he now, seeing his brain before him, understand himself as a man whose thoughts are occurring not in his body but in his brain in the vat? No. In fact – apart from remembering who he is and realising that he is not a scarecrow – he feels no different. The Wizard is content that the experiment has validated his hypothesis.ii

The mainland across the bay looks beautiful today, bathed as it is in hazy sunshine. I am now being located there, but only very poorly – this sensorium is so restrictive. Perhaps I’ll pour another coffee, go and sit outside, and try to think some thoughts I’ve never thunk before.


i Daniel C. Dennett, Consciousness Explained (London: Penguin, 1993), 310.
ii Much of the above is based upon Daniel C. Dennett, “Where Am I?,” in Brainstorms: Philosophical Essays on Mind and Psychology (Cambridge, Mass.: MIT Press, 1981).

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