Identity
A philosopher once had the following dream.
First Aristotle appeared, and the philosopher said to him, “Could you give me a fifteen-minute capsule sketch of your entire philosophy?” To the philosopher’s surprise, Aristotle gave him an excellent exposition in which he compressed an enormous amount of material into a mere fifteen minutes. But then the philosopher raised a certain objection which Aristotle couldn’t answer. Confounded, Aristotle disappeared.
Then Plato appeared. The same thing happened again, and the philosopher’s objection to Plato was the same as his objection to Aristotle. Plato also couldn’t answer it and disappeared.
Then all the famous philosophers of history appeared one by one and our philosopher refuted every one with the same objection.
After the last philosopher vanished, our philosopher said to himself, “I know I’m asleep and dreaming all this. Yet I’ve found a universal refutation for all philosophical systems! Tomorrow when I wake up, I will probably have forgotten it, and the world will really miss something!” With an iron effort, the philosopher forced himself to wake up, rush over to his desk, and write down his universal refutation. Then he jumped back into bed with a sigh of relief.
The next morning when he awoke, he went over to the desk to see what he had written. It was, “That’s what you say.”
What I wonder about ever more than whether or not I am conscious or exercise free will is why I happen to be conscious of the experiences and decisions of this one particular person who writes books, enjoys hiking and biking, takes nutritional supplements, and so on. An obvious answer would be, “Because that’s who you are.”
That exchange is probably no more tautological than my answers above to questions about consciousness and free will. But actually I do have a better answer for why my consciousness is associated with this particular person: It is because that is who I created myself to be.
A common aphorism is, “You are what you eat.” It is even more true to say, “You are what you think.” As we have discussed, all of the hierarchical structures in my neocortex that define my personality, skills, and knowledge are the result of my own thoughts and experiences. The people I choose to interact with and the ideas and projects I choose to engage in are all primary determinants of who I become. For that matter, what I eat also reflects the decisions made by my neocortex. Accepting the positive side of the free will duality for the moment, it is my own decisions that result in who I am.
Regardless of how we came to be who we are, each of us has the desire for our identity to persist. If you didn’t have the will to survive, you wouldn’t be here reading this book. Every creature has that goal—it is the principal determinant of evolution. The issue of identity is perhaps even harder to define than consciousness or free will, but is arguably more important. After all, we need to know what we are if we seek to preserve our existence.
Consider this thought experiment: You are in the future with technologies more advanced than today’s. While you are sleeping, some group scans your brain and picks up every salient detail. Perhaps they do this with blood cell–sized scanning machines traveling in the capillaries of your brain or with some other suitable noninvasive technology, but they have all of the information about your brain at a particular point in time. They also pick up and record any bodily details that might reflect on your state of mind, such as the endocrine system. They instantiate this “mind file” in a nonbiological body that looks and moves like you and has the requisite subtlety and suppleness to pass for you. In the morning you are informed about this transfer and you watch (perhaps without being noticed) your mind clone, whom we’ll call You 2. You 2 is talking about his or her life as if s/he were you, and relating how s/he discovered that very morning that s/he had been given a much more durable new version 2.0 body. “Hey, I kind of like this new body!” s/he exclaims.
The first question to consider is: Is You 2 conscious? Well, s/he certainly seems to be. S/he passes the test I articulated earlier, in that s/he has the subtle cues of being a feeling, conscious person. If you are conscious, then so too is You 2.
So if you were to, uh, disappear, no one would notice. You 2 would go around claiming to be you. All of your friends and loved ones would be content with the situation and perhaps pleased that you now have a more durable body and mental substrate than you used to have. Perhaps your more philosophically minded friends would express concerns, but for the most part, everybody would be happy, including you, or at least the person who is convincingly claiming to be you.
So we don’t need your old body and brain anymore, right? Okay if we dispose of it?
You’re probably not going to go along with this. I indicated that the scan was noninvasive, so you are still around and still conscious. Moreover your sense of identity is still with you, not with You 2, even though You 2 thinks s/he is a continuation of you. You 2 might not even be aware that you exist or ever existed. In fact you would not be aware of the existence of You 2 either, if we hadn’t told you about it.
Our conclusion? You 2 is conscious but is a different person than you—You 2 has a different identity. S/he is extremely similar, much more so than a mere genetic clone, because s/he also shares all of your neocortical patterns and connections. Or I should say s/he shared those patterns at the moment s/he was created. At that point, the two of you started to go your own ways, neocortically speaking. You are still around. You are not having the same experiences as You 2. Bottom line: You 2 is not you.
Okay, so far so good. Now consider another thought experiment—one that is, I believe, more realistic in terms of what the future will bring. You undergo a procedure to replace a very small part of your brain with a nonbiological unit. You’re convinced that it’s safe, and there are reports of various benefits.
This is not so far-fetched, as it is done routinely for people with neurological and sensory impairments, such as the neural implant for Parkinson’s disease and cochlear implants for the deaf. In these cases the computerized device is placed inside the body but outside the brain yet connected into the brain (or in the case of the cochlear implants, to the auditory nerve). In my view the fact that the actual computer is physically placed outside the actual brain is not philosophically significant: We are effectively augmenting the brain and replacing with a computerized device those of its functions that no longer work properly. In the 2030s, when intelligent computerized devices will be the size of blood cells (and keep in mind that white blood cells are sufficiently intelligent to recognize and combat pathogens), we will introduce them noninvasively, no surgery required.
Returning to our future scenario, you have the procedure, and as promised, it works just fine—certain of your capabilities have improved. (You have better memory, perhaps.) So are you still you? Your friends certainly think so. You think so. There is no good argument that you’re suddenly a different person. Obviously, you underwent the procedure in order to effect a change in something, but you are still the same you. Your identity hasn’t changed. Someone else’s consciousness didn’t suddenly take over your body.