The Personal/Sub-Personal Distinction

19. THE PERSONAL/SUB-PERSONAL DISTINCTION

Your eyes don’t see; you do. Your mouth doesn’t enjoy chocolate cake; you do. Your brain doesn’t abhor the stinging pain in your shoulder; you do. Your hand doesn’t sign a contract; you do. Your body may be aroused, but you fall in love. This is not just a “grammatical” point, like the fact that we say, “It’s raining,” when there is a thunderstorm, not “the thunderstorm is raining.” Nor is it just a matter of definitional convention. People sometimes ask, dismissively, “Isn’t this just semantics?” which is taken to mean that nothing much hangs on how we “define our terms.” But how we define our terms often does make a big difference, and this is one of those times. Our way of speaking about persons and what they can do and suffer is grounded in some important facts.

At first blush it seems that there are things a whole person can do that none of a person’s proper parts can do, and this is almost right, but a ghoulish exercise of imagination suggests that if this is so, then a person is (roughly) a proper part of a human body, namely, an intact and functioning brain. (Do you have a brain, or are you a brain? Not a straightforward question to answer.) If you cut off my arms, I can still sign a contract (with a pen in my toes or a vocal directive), but if you shut down my brain, nothing my arms and hands could do counts as signing a contract. Pluck out my eyes and I cannot see, unless I get fitted with prosthetic eyeballs, which are not such a distant science-fiction fantasy. What if you start “amputating” parts of my brain? If you were to remove the occipital cortex while leaving my eyes and optic nerve intact, I would be “cortically blind” but might still have some residual visual competence (for instance, the famous condition known as blindsight). No doubt we could amputate a bit more brain and wipe out the blindsight, while still leaving you a life to lead. The tempting idea is that such a process of elimination, removing hearing, touch, taste, and smell, could pare down the brain to the ultimate headquarters of you—and that is where, and what, a person would be. Tempting but wrong. The brain’s multitudinous competences are so intertwined and interacting that there simply is no central place in the brain “where it all comes together” for consciousness.1 For that matter, many of the competences, dispositions, preferences, and quirks that make you you depend on paths through your body outside your brain; the always popular philosophical thought experiment of the brain transplant (which would you rather be: the brain “donor” or the brain “recipient”?) is enabled by a very distorting idealization. As I once put it, “One cannot tear me from my body, leaving a nice clean edge” (1996a, p. 77).

Probably the most important property of the Internet is its decentralization; it has no hub or headquarters anywhere in the world where dropping a well-placed bomb would kill it. Its proper parts have a high degree of redundancy and versatility, so it “degrades gracefully” if it degrades at all when any proper part of it is disabled. Hal, the intelligent computer in 2001: A Space Odyssey, has a “Logic Memory Center,” a room full of memory cassettes that Dave can detach one by one, shutting Hal down for good. The Internet has no such center, and while nature has not equipped us with quite such a fine level of distributed invulnerability, there is still considerable decentralization of you in your body, and considerable versatility in your parts. The organization of your brain proves to be remarkably plastic (able to morph into new configurations) so that you can go on being you, pursuing your dreams, confounding your enemies, concocting your stratagems, reliving your trials and triumphs, in spite of the removal of important but not quite “vital” bodily parts. That is one reason why you can have competences that none of your parts have. Or we can turn the point inside out: the only way to understand or make sense of the powers of the parts of a whole live body is to consider how they contribute to the coordination of the whole magnificent system.

Consider a few more instances: Your brain doesn’t understand English; you do. Your brain doesn’t find the joke hilarious; you do. Even if the activities of competent structures in your brain play the major causal roles in your understanding and appreciation, they couldn’t do their work without the training and support provided, over the years, by all your sense organs and limbs and other effectors.2

So it is not just conventional when we posit a person, the enduring, conscious, rational agent whose live body this is, as the subject of record for most of our everyday attributions: it is you who made the mistake, won the race, had a crush on Leslie, speak passable French, want to go to Brazil, prefer blondes, committed the libel. (See also chapter 62.) You are hungry, tired, and peevish, all thanks to your sub-personal parts—and nothing else.

But then what about those proper parts? Are they just like bricks stacked up into a living human body? The answer is yes, if we look at the smallest parts: atoms. But it is no at every other level, from the molecular to the cellular and higher. The proteins that are the workhorses inside your cells are amazingly competent and discriminating little robots—nanobots, we might call them. The neurons that do most of the transmission and switching and adjusting work in your brain are more versatile and competent robots—microbots, we might call them. They form coalitions that compete and cooperate in larger structures, communicating back and forth, suppressing each other, analyzing the flood of information from the senses, waking up dormant information structures “in memory” (which is not a separate place in the brain), and orchestrating the subtle cascades of signals that move your muscles when you act.

All these levels higher than the basic atomic building blocks exhibit a degree of agency. In other words, they are interpretable as intentional systems. At the molecular level (motor proteins, DNA proofreading enzymes, gatekeepers at trillions of portals in the membranes of your cells, and the like), their competences are very “robotic” but still impressive, like the armies of marching brooms in The Sorcerer’s Apprentice, or Maxwell’s Demon, to take two fictional examples. At the cell level, the individual neurons are more exploratory in their behavior , poking around in search of better connections, changing their patterns of firing as a function of their recent experience. They are like prisoners or slaves rather than mere machines (like the protein nanobots); you might think of them as nerve cells in jail cells, myopically engaged in mass projects of which they have no inkling, but ever eager to improve their lot by changing their policies. At higher levels, the myopia begins to dissipate, as groups of cells—tracts, columns, ganglia, “nuclei”—take on specialized roles that are sensitive to ever-wider conditions, including conditions in the external world. The sense of agency here is even stronger, because the “jobs done” require considerable discernment and even decision-making.

These agents are like white-collar workers, analysts and executives with particular responsibilities, but also, like white-collar workers everywhere, they have a healthy dose of competitive zeal and a willingness to appropriate any power they encounter in the course of their activities, or even usurp control of any ill-defended activities engaged in by their neighbors or others in communication with them. When we reach agents at this level of competence, the sub-personal parts are intelligent bricks indeed, and we can begin to see, at least in sketchy outline, how we might fashion a whole comprehending person out of them. (“Some assembly required,” as it says on the carton containing all the bicycle parts, but at least we don’t have to cut and bend the metal, and make the nuts and bolts.)

This idea, that we can divide and conquer the daunting problem of imagining how a person could be composed of (nothing but) mindless molecules, can be looked at bottom-up, as we have just done, or top-down, starting with the whole person and asking what smallish collection of very smart homunculi could conspire to do all the jobs that have to be done to keep a person going. Plato pioneered the top-down approach. His analysis of the soul into three agent-like parts, analogized to the Guardians, the Auxiliaries, and the Workers, or the rational, the spirited, and the appetitive, was not a very good start, for reasons well analyzed over the last two millennia. Freud’s id, ego, and superego of the last century was something of an improvement, but the enterprise of breaking down a whole mind into sub-minds really began to take shape with the invention of the computer and the birth of the field of artificial intelligence (AI), which at the outset had the explicit goal of analyzing the cognitive competences of a whole (adult, conscious, language-using) person into a vast network of sub-personal specialists, such as the goal-generator, the memory-searcher, the plan-evaluator, the perception-analyzer, the sentence-parser, and so on.

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1 This is the central claim argued in my book Consciousness Explained (1991a); the idea of such a special place—I call it the Cartesian Theater—is apparently indomitably tempting, for many thinkers still don’t get it, in spite of all the reasons advanced by me and others.

2 It is not often remarked that in that favorite thought experiment of philosophers, the brain in the vat, the living brain has to have had a life in a body to configure all the hardware with the software of years of experience. If you were “just” to build a brain from scratch, letting the connections between elements be whatever they happened to be (wiring up the brand-new brain at random, in other words), the probability of the brain having any competence, harboring any coherent ideas or intentions or projects, or any (apparent) memories would be Vanishing (see chapter 35). See also chapter 32.