For the twirlwind trip just undertaken, I set the knobs determining Twinwirld at a middle-range level in order to make both analogies roughly equally plausible, hence to make the competition between “i” and “Twe” quite tight. But now I want to tweak Twinwirld so as to make “Twe” a bit stronger. In this new fantasy world, which I’ll dub “Siamese Twinwirld”, instead of positing that 99 percent of births yield standard identical twins, I’ll posit that 99 percent of births yield Siamese twins joined, say, at the hip. Moreover, I’ll stipulate that the Twinwirld pronoun “i” doesn’t exist in Siamese Twinwirld. Now the only analogy that remains is that between our concept of “I” and their concept of “Twe”. This may seem extremely far-fetched, but the curious thing is, our standard earthly world has much in common with Siamese Twinwirld. Here’s why.
We all possess two cerebral hemispheres (left and right halves), each of which can function pretty well as a brain on its own, in case one side of our brain is damaged. I’ll presume that both of your hemispheres are in good shape, dear reader, in which case what you mean when you say “I” involves a very tight team consisting of your left and right half-brains, each of which is fed directly by just one of your eyes and just one of your ears. The communication between your team’s two members is so strong and rapid, however, that the fused entity — the team itself — seems like just one thing, one absolutely unbreakable self. You know just what this feels like because it’s how you are constructed! And if you’re anything like me, neither of your half-brains goes around calling itself “i” and brazenly proclaiming itself an autonomous soul! Rather, the two of them together make just one capital “I”. In short, our own human condition in this, the real world, is quite analogous to that of pairsons in Siamese Twinwirld.
The communication between the two halves of a dividual in Twinwirld (whether it’s the Siamese variant or the original one) is, of course, less efficient than that between the two cerebral hemispheres inside a human head, because our hemispheres are hard-wired together. On the other hand, the communication between halves in Twinwirld is more efficient than that between nearly any two individuals in our “normal” world. And so the degree of fusing-together of two Twinwirld halves, though not as deep as that between two cerebral hemispheres, is deeper than that between two very close siblings in our world, deeper than that between identical twins, deeper than that between wife and husband.
Post Scriptum re Twinwirld
After I had written a first draft of this chapter and had moved on to the following one, which is based on emails exchanged between Dan Dennett and myself in 1994, I noticed that in one of his messages to me he referred to an unusual pair of twins in England that he had mentioned in his 1991 book
We can imagine.… two or more bodies sharing a single self. There may actually be such a case, in York, England: the Chaplin twins, Greta and Freda (
I’m not for a moment suggesting that these twins were linked by telepathy or ESP or any other sort of occult bonds. I am suggesting that there are plenty of subtle, everyday ways of communicating and coordinating (techniques often highly developed by identical twins, in fact). Since these twins have seen, heard, touched, smelled, and thought about very much the same events throughout their lives, and started, no doubt, with brains quite similarly disposed to react to these stimuli, it might not take enormous channels of communication to keep them homing in on some sort of loose harmony. (And besides, how unified is the most self-possessed among us?)….
But in any case, wouldn’t there also be two clearly defined individual selves, one for each twin, and responsible for maintaining this curious charade? Perhaps, but what if each of these women had become so selfless (as we do say) in her devotion to the joint cause that she more or less lost herself (as we also say) in the project?