Archive for the ‘Reasons and Persons’ Category

The Anatomy of Self-Concern

Friday, May 21st, 2010

 

Published in 1998, Raymond Martin’s Self-Concern set a new direction for the philosophical discussion of personal identity by shifting the focus from “the normative question of whether this or that should matter in survival to the largely descriptive question of what…actually does…matter.”  Martin questions the philosophical goal of trying to show that we all should (rationally) respond in the same way to the puzzle cases – a goal shared by Parfit and his opponents – calling the attempt “survival-value imperialism.”  In examining how people actually value their own survival, his book goes a long way towards characterizing the conditions that make it difficult or easy for people to self-identify across time.  It is largely about the psychology of self-concern. (more…)

The Self Illusion

Monday, February 1st, 2010

Vase-faces2

To find the right answers, ask the right questions.  I have skated around the question, “Is there a rational justification for self concern?” without coming up with a solid argument that settles it one way or the other.  But there is a related question which can be answered.

Two Views of Teleportation

As we have seen, teleportation by means of information transfer can be viewed in two ways.  The facts of the case are: I am scanned in North Vancouver and my information is sent to Omaha, where it is used to construct a living replica of me.  Meanwhile, the original in North Vancouver is destroyed.  Two views of these events are:

SURVIVE: I am transported from North Vancouver to Omaha.

DIE: I am killed in North Vancouver, and someone else – my replica – is constructed in Omaha.

People who think about teleportation disagree about whether SURVIVE or DIE is an accurate description of the case.  How can it be settled which view is true – or whether neither is true?

People who disagree about SURVIVE and DIE do not disagree about the facts of the case.  The facts are not in question.  No scientific experiment can be devised to settle which of SURVIVE and DIE is an accurate description of the facts. (more…)

Gappy Things That Branch and Change

Thursday, January 14th, 2010

IdentityImagine, in the early days of books, a small library consisting entirely of original manuscripts.  Some of them are very old, and have been attacked by mice.  Some have deteriorated so much that their pages crumble to dust when the custodian of the library tries to read them.  He mourns the loss of these books, and contemplates the inevitable decay of the remaining books with sorrow.  To be sure, new manuscripts are occasionally added to the library, but they cannot replace the volumes that are lost forever.  This goes on until, one day, the young assistant librarian has an idea.  “This book will be unreadable in five years,” he tells his elder.  “But I can read it now.  If I copy the words of this book onto sheets of new vellum, and bind them in a strong new binding, we will be able to read it for many decades to come.”  The old librarian tenderly strokes the cracked spine of the crumbling volume, and shakes his head.  “What good is a copy?  It wouldn’t be the same book.”

In the previous post, I summarized one of Derek Parfit’s main arguments that personal identity – being the same person over time – is not what matters in survival.

Human fission – one person ‘splitting’ into two – is clearly imaginable.  It is physically possible, and is not far from being technically possible.  Parfit argues compellingly that fission would preserve what is important in survival.  Specifically, if Parfit knew that both of his cerebral hemispheres were about to be separately transplanted into two separate bodies, he would have the same rational justification for anticipating the experiences of both of the post-op survivors as each of us has for anticipating his or her own future experiences.  This, despite the fact that the original Derek Parfit ceased to exist when he was divided.  In this case, ceasing to exist is very unlike ordinary death.  Ceasing to exist just consists in the fact that the two post-op survivors are different persons from one another, and neither one is the same person as the pre-op Derek Parfit.  Loss of identity of this kind does not matter. (more…)

Parfit on What Matters

Friday, January 1st, 2010

Parfit's Division1Part Three of Derek Parfit’s Reasons and Persons is titled “Personal Identity”.  One of its central claims is what Parfit calls the Reductionist View: that persons are not “separately existing entities” over and above their brains and bodies.  What is important about being the same person at different times consists primarily in psychological continuity and connectedness.

Another, related claim is that being the same person is not in itself very important.  In particular, it is not a rational justification for self-concern.  If I know that someone in the future will not be myself, that is not a good reason not to anticipate having that person’s experiences.  What is important are the underlying, real relations of psychological continuity and connectedness.  And even they do not have exactly the same importance that we tend to believe personal identity has.

Part Three of Reasons and Persons contains 150 pages of closely-reasoned arguments which are by and large original, compelling, and illuminating.  I will not try to restate all of Parfit’s arguments, or to comment on them all; instead, I strongly recommend his book to anyone interested in this subject.   In this post, I will review one of Parfit’s more important lines of argument in Chapter 12, “Why Our Identity is Not What Matters.”

Brain-Splitting

Parfit begins this chapter by making a refreshing break from the philosophical practice of thought-experiments, building instead on actual cases documented in medical literature.  These are the famous ‘split-brain’ cases, in which surgeons severed the corpus callosum, the main bundle of nerve fibres connecting the left and right hemispheres of the human brain, as a treatment for epilepsy.  Cutting the connection reduces the severity of epileptic attacks by preventing seizures from spreading from one hemisphere to the other.  But there are side-effects.

The effect, in the words of one surgeon, was the creation of ‘two separate spheres of consciousness’.  (p 245) (more…)