ACHILLES: I’m obviously deader when the machine breaks, because there is no expectation that I will ever resume functioning… whereas when A-kill-ease takes off on his sprees, he will eventually return to his duty.
TORTOISE: You mean, if you have been abandoned, you are still alive, just because A-kill-ease has the intention of returning? But when the machine breaks, you are dead?
ACHILLES: That would be a very silly way of defining “aliveness” and “deadness.” Certainly such concepts should have nothing to do with the mere intentions of other beings. It would be as silly as saying that a light bulb is “dead” if its owner has no intention of turning it on again. Intrinsically, the light bulb is the same as ever—and that’s what counts. In my case, what counts is that that book should be kept intact.
TORTOISE: You mean, that it should all be there, all at once? Its mere presence there is what guarantees your aliveness? Just as the existence of a playing-record is tantamount to the existence of its music?
ACHILLES: A funny image comes into my head. The earth is destroyed, but one record of Bach’s music somehow escapes and goes sailing out into the void of space. Does the music still exist? It would be silly to make the answer depend upon whether it is ever found and played by some humanlike creature—wouldn’t it? To you, Mr. T, the music exists as the record itself. Similarly, when we come back to that book, I feel that if the book merely sits there, all at once, I’m still there. But if that book is destroyed, I’m gone.
TORTOISE: You maintain that as long as those numbers and conversion tables are in existence, you are essentially, potentially alive?
ACHILLES: Yes; that’s it. That’s what’s all important—the integrity of my brain structure.
TORTOISE: Do you mind if I just ask, “Suppose someone absconded with the instructions in the preface, telling how to use the book?”
ACHILLES: Well, they’d better bring them back, is all I can say. My goose would be cooked if they weren’t going to return those instructions. What good’s the book without its instructions?
TORTOISE: Once again you are saying that the question as to whether you are alive depends on whether the filcher has good intentions or bad. It could just as well have been the capricious wind, blowing about, which caught hold of those few pages of preface and wafted them into the air. Now there’s no question of intention. Would “you” be less alive for that?
ACHILLES: This is a little tricky. Let me go over the question slowly. I die; my brain is transcribed into a book; the book has a set of instructions telling how to process the book’s pages in a way that parallels how my neurons fire in my actual brain right now.
TORTOISE: And the book, together with its instructions, lies on a dusty shelf in a far corner of a used book store. A chap comes in and chances upon the oddity. “Egads!” he exclaims, “An Achilles-book! What on earth could that be? I’ll buy it and try it!”
ACHILLES: He should be sure to buy the instructions too! It is essential that the book and instructions remain together.
TORTOISE: How close? In the same binding? In the same bag? In the same house? Within a mile of each other? Is your existence somehow diminished if the pages are scattered hither and thither by a breeze? At what precise point would you feel the book had lost its structural integrity? You know, I appreciate a warped playing-record fully as much as a flat one. In fact, it’s got an extra bit of charm, to the cultured eye. Why, I have a friend who considers broken records more stylish than the originals! You should see his walls—they’re plastered with broken Bach-fragmented fugues, crushed canons, ruptured ricercari. He delights in it. Structural integrity is in the eye of the beholder, my friend.
ACHILLES: Well, as long as you’re asking me to be the beholder, I’d say that if the pages are to be reunited, there is still hope for my survival.
TORTOISE: Reunited in whose eyes? Once you’re dead, you the beholder remain only in book form (if at all). Once the book’s pages start being scattered, will you feel yourself losing structural integrity? Or, front the outside, once I feel that the structure is irretrievably gone, should I conclude that you no longer exist? Or does some “essence” of you exist still, in scattered form? Who will judge?
ACHILLES: Oh, goodness. I have totally lost track of the progress of that poor soul inside the book. And as to what he himself—or I myself—would be feeling, I am even more unsure.
TORTOISE: “That poor soul inside the book”? Oh, Achilles! Are you still clinging to that old notion that it’s “you” somehow there, inside that book? If I am correct in my memory, you were so reluctant at first to accept that kind of idea when I suggested that you really were talking to Einstein himself.
ACHILLES: Well, I was reluctant until I saw that it—the book—seemed to feel, or at least to express, all his—Einstein’s—emotions, or what seemed like emotions. But maybe you’re right to chide me—maybe I should just trust the old, familiar commonsense view that the only real “I” is right here, inside my very own living, organic brain.
TORTOISE: You mean, the old, familiar “ghost-inside-the-machine” theory, is that it? What is it, inside there, that this “you” is?
ACHILLES: It’s whatever feels all these emotions that I express.
TORTOISE: Maybe the feeling of those emotions is the sheer physical event of having a shower of electrochemical activity come flying through some one of the various neural pathways inside your brain. Maybe you use the word “feeling” to describe such an event.
ACHILLES: That sounds wrong, because the book uses the word “feeling,” if I do, and yet it can feel no electrochemical activity surging. All that the book “feels” is its numbers changing. Perhaps “feeling” is synonymous with the existence of any kind of neural activity, simulated or otherwise.
TORTOISE: Such a view would place undue stress on the unfolding of feeling “a bit at a time.” While the time development of a neural structure undoubtedly seems to us like the essence of feeling, why could it not be that feelings, like playing-records and paintings, are there “all at once”?
ACHILLES: The difference I can immediately spot between a playing-record of a piece of music, and a mind, is that the former does not change by evolving “a bit at a time”; but a mind, in its interaction over a span of time with the exterior world, gets modified a way that was not originally inherent in its physical structure.
TORTOISE: You have a good point. A mind, or brain, interacts with t world and thus is subject to change that one cannot predict by knowing the structure of the brain alone. But this does not in any way diminish the “aliveness” of said mind, when it introspectively ponders some thought, without any interference from without. During such a period of introspection, the changes it undergoes are inherent in it. Though it is evolving “a bit at a time,” it is inherently there “all at once.” I can clarify what I mean by drawing a parallel to a simpler system. The entire path of a thrown grapefruit is inherent once the grapefruit is released. Watching the fruit in flight is one way—the usual way—of experiencing its motion; it could be labeled the “bit-at-a-time” picture of its motion. But just knowing its initial position and velocity is another equally valid way of experiencing the motion; this picture of the motion could be labeled the “all-at-once” picture. Of course, in this picture we assume no interference by passing storks and so forth. A brain (or a brain catalogue) shares this dual nature; as long as it is not interacting with the exterior world a being modified in ways foreign to it, its time development can viewed either in the “bit-at-a-time” picture or in the “all-at-once” picture. The latter picture is one that I advocate and that I thought you had come to agree with, when you described the record sailing out into space.