Thursday, August 27, 2009

Concerning Intuitions of Immortality

On the face of it, dead is dead. Yet many people, perhaps a majority both now and in the past, don't believe it. Why?

The obvious explanation for the belief in life after death is wishful thinking. I don't want to believe I am going to die. I don't want to believe that those dear to me are going to die. I don't want to believe that those dear to me who have died are really dead. With enough effort, and help from those around me, I can convince myself not to.

While this may be part of the explanation, I don’t think it is the whole story.

My main reason is introspection, most recently of my feelings about my mother, who died just over a week ago. She was in her late nineties. Her one serious complaint about her life was that, after more than sixty years of a happy marriage, she had not died when my father did. I miss her, and for my sake I would rather she were still alive. But not for her sake.

It is easy for me to believe that she died. It is not so easy to believe that she is dead, that a person I have known all my life no longer exists anywhere in the world, that if I knock at the back door of the apartment where she spent her last few years she will not be there to let me in. Ever. I feel much the same way about other people I have known who are no longer alive. A dream where my father's death did not happen, was somehow a mistake, feels in some sense more believable than the real world where it did happen.

The explanation of my feelings, I think, lies in an important feature of the human mind. In order to function in the world, we need a model, a picture of what surrounds us. Deducing such a picture on the basis of sensory data alone is surprisingly hard, as A.I. researchers discovered when they tried to create machines that could do it. The data coming in from my retina is a pattern of colored dots; no part of it is labelled "cup sitting on my desk," "bunch of keys," or "mouse." To get from that to a model of the world around me requires a lot of image processing and a lot of additional information.

Some of that information comes from past sensory data. But much of it, I believe, is hard wired, the product of many millions of years of evolution. The image processing software built into my brain knows quite a lot about the characteristics of the world I am looking at. That knowledge lets it eliminate most of the conceivable explanations of what appears in my visual field, leaving, usually, the explanation that describes what I am seeing more or less correctly.

One of the things it knows is continuity, persistence. If an object is sitting on my desk, the odds are overwhelmingly high that, a second later, the same object, or at least a very similar object, will be in the same place or very close. I don't need to reanalyze the visual data on every scan. That is why soap bubbles seem magical, counterintuitive. They break the rules.

Other human beings are among the most important features of the our world. Also among the most distinctive. It is easy to confuse one cup for another, one house for another, one tree for another. It is hard to imagine knowing someone well, encountering him, talking with him, and not recognizing him, or misidentifying one person you know well as another.

Applying the rule that works for almost everything else to this salient class of distinct objects, it is obvious that a human being I have once known cannot vanish, hence that, while personality may change over time and inessential features such as clothing or body may change or even disappear, the person himself must still exist. Somewhere.

It is not an argument, still less a proof. My best guess is that dead really is dead, that the person is software running on the hardware of the brain and when the hardware stops functioning the person ceases to exists. It is, however, an explanation of why I find it hard to entirely believe in death.

And, perhaps, of why so many other people feel the same way.