Thursday, July 9, 2009

A Possible Paradox of Personal Identity

I say "possible paradox" because I am not ready to commit to the idea that there is a paradox here at all. I only want to suggest that there might be a legitimate paradox implicit in the notion of personal identity.

It does not require an extreme amount of philosophical sophistication to recognize that personal identity is somewhat elusive. It is easy to see how the notion of identity breaks down when we think of it in terms of the body. For, we would still call ourselves by the same name were we to lose any or all limbs, organs, or bodily functions, so long as we had a set of memories or perceptions which defined ourselves as such. We are thus tempted to locate the essence of personal identity in the brain, in those processes which ground our memories and perceptions. Yet, even here we realize the notion of identity lacks foundation. For we can imagine our memories and perceptions being simulated by something other than our brain, a biological clone or computerized twin which would think of itself just as we think of ourselves.

The final temptation, then, is to think of personal identity as an abstraction, as a formal pattern or conventionally defined set of properties which do not depend on any particular organism for its existence. The self is an idea, and not a thing. It is thus supposed that there is a mind/body problem, an idea/thing problem, which philosophers must solve in order to understand what it means to be a person.

What we must pause to recognize is that the idea of this "problem" is based on the temptation to think of identity as an abstraction, as opposed to a thing. The question is, what is gained by giving in to this temptation? In other words, what question is answered by thinking of identity in these terms?

My suggestion is that nothing is solved at all. The temptation to postulate mind/body dualism offers no rewards. It tempts us, not because of any understanding it offers, but precisely because it offers an excuse for not understanding the nature of identity. When we say that the self is an abstraction, an idea, and not a thing, we are not explaining anything; we are only offering an excuse for not being able to explain something.

To see this more clearly, try to decipher what understanding might be gained by thinking of the self as an idea, as opposed to a thing. Consider, for example, what it would mean if some clone or computer simulated your identity. Under what conditions would you agree that, yes, that clone/computer was actually you?

I suggest that there are no such conditions. There is no possibility of any organism/machine seeming to you to be you. Of course, a machine could seem to somebody else to be you. But to you, it will always seem different. So long as you exist, then, there is a real, tangible difference between your identity and the identity of a machine which simulated you to any imaginable degree of perfection.

Imagine a clone of you is made and provided with an exact replication of your mental states. With each divergent experience, you and your clone will become different people. There are thus obvious experiential grounds for recognizing that you and your clone will not be the same. Yet, it is also obvious that some time must elapse before these differences become significant. There is a period, however brief, during which you and your clone have identical (or identical enough) mental states and physiological characteristics. During this period, you and your clone look at each other and utter in unison, "That's not me!"

There is no significant difference in you and your clone's perception of a self. There is no significant different in your physiology. Yet, to each of you, the other is not you. Thus, the idea that your identity is defined by any such mental properties, however tempting, is no more accurate than the idea that your identity is defined by the physical particulars of your body. Just as the notion of identity collapses when we try to locate it in the body, so does it collapse when we try to locate it in the mind, or any formal properties thereof.

This would seem to make the notion of identity a paradox. The notion clearly refers in a great many ways. It serves a valuable purpose in our lives. Yet, it has no discernable referent. At least, nothing which in all cases can be identified as such.