Where does Bruce Lee end? Where do you begin? Is there even a "you" in the first place?

Derek Parfit (b. 1942)

[Image taken from here]

"When I believed that my existence was such a further fact, I seemed imprisoned in myself. My life seemed like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness. When I changed my view, the walls of my glass tunnel disappeared. I now live in the open air. There is still a difference between my life and the lives of other people. But the difference is less. Other people are closer. I am less concerned about the rest of my own life, and more concerned about the lives of others."

Derek Parfit

Who or what am I? Is there even an "I" in the first place? If there is no "I", how should I live my life? The philosopher Derek Parfit has spent his entire life and career asking and trying to answer these questions.

To get a sense of what Parfit is up to, consider this rather fantastical thought experiment. Suppose a crazy scientist were to begin replacing your cells, one by one, with those of Bruce Lee at the age of thirty (We should also suppose, further, that the scientist has somehow managed to preserve Bruce Lee's body in perfect condition all these years. And really, it doesn't have to be Bruce Lee. Just pick your favorite dead celebrity.).

At the beginning of this cell-replacement procedure, the person who is receiving the cells would clearly be you. After all, you minus one or two of your own cells, and plus one or two cells from Bruce Lee would still be you (I would think). At the end of the procedure, the person who emerges would clearly be Bruce Lee. But is Bruce Lee minus one of his cells (and plus one of yours) still Bruce Lee? What about Bruce Lee minus, say, a hundred of his cells, and plus a hundred of yours? The question here is: At what point during the procedure do you cease to be you and become Bruce Lee? It seems very difficult, if not impossible, to try to pinpoint when exactly in the procedure this change of identity occurs.

Many philosophers throughout history have wrestled with problems of this kind, trying not very successfully to pinpoint the moment of identity change at various points in the procedure. Parfit, however, draws an interesting conclusion from this thought experiment: Perhaps the very fact that we cannot pinpoint any particular moment means that there is really no such thing as personal identity in the first place. There is really no Bruce Lee, and no you! Personal identity is, at most, a convenient fiction that we employ to get through our everyday lives. In our everyday lives, we say that this particular bundle of physical parts and properties and psychological characteristics is you. And that bundle of physical facts and properties and psychological characteristics who "died" in 1973 after the filming of Enter the Dragon is Bruce Lee. But when we try to pinpoint where one bundle ends and another bundle begins, as we did in the thought experiment above, we get stumped. Which suggests, according to Parfit, that there is really no such thing as a distinct person or self called Bruce Lee, or a distinct person or self called [insert your name here].

The bundle that is "Bruce Lee" locked in mortal combat with the bundle that is "Chuck Norris"

(Can you tell where Chuck ends and Bruce begins?)

[Image taken from here]     

If there is no enduring further fact that we can point to and identify as our "self", over and above the multitude of physical and psychological facts and properties that we commonly associate with "you", what implications would this have for how we should go about living our lives?

Parfit, for one, finds the discovery that there is no further fact of self or personal identity to be a very liberating one. If there is really no self, then there is also really no such things as "my" life or "my" possessions, beyond their utility as convenient fictions to facilitate everyday life. Perhaps more importantly, the prospect of death will probably be less frightening if there is no "self" or "I" that actually dies. Parfit sees it this way:

"My death will break the more direct relations between my present experience and future experiences, but it will not break various other relations."

Even if there is no "I", various other relations will still persist between "I" and others after my death. People will (hopefully) remember me. They may also be influenced by my writings or thoughts (including, perhaps, those that are found on this blog ;-)), and conduct their lives and take actions in accordance with such influences. In this way, the "I" that never really existed in the first place will, paradoxically, continue to live on via other people's memories, thoughts and actions. Parfit concludes:

"This is all there is to the fact that there will be no one living who will be me. Now that I have seen this, my death seems to me less bad." 

Very interesting, don't you think? I find Parfit's views very fascinating and intriguing, and his arguments very compelling. But there is a part of me that is reluctant to accept the idea that there is really no "I". Well, I don't know. I guess I'm going to take the weekend to mull over all this a little more :-)