I. Introduction
Last month, all of us living in Britain received the forms for the 2011 Census. The British government wants to know how many people live at a certain address, how old they are, how far they travel to work and so on. Looking for a demographic snapshot of the country, the Office for National Statistics is not interested if these people are identical with the people counted at the last census 10 years ago.
For philosophers it is however an important question if the person that lived 10 years ago at your address, had your name and the same family and job as you have now, is indeed identical with who you are today.
One attempt to make sense of this question is the Psychological Continuity Account on which this paper will concentrate.
II. What is the Psychological Continuity Account
According to the Psychological Continuity Account, two people A and B are the same person if and only if B’s psychological states are continuous with A’s psychological states1. The survival of memories and personality traits is what defines a person’s identity2. To put is as concise as possible: A person is his/her mind, as opposed to his/her body3 (as the proponents of the Bodily Continuity Account would see it).
The continuity of two psychological states is presumed to exist if the later psychological state has developed from the prior psychological state4. This can happen either directly or indirectly, through intervening steps5. These steps may change the psychological state, but each step must not exceed the scope of gradual change in comparison to the previous state6. A sudden, dramatic change would interrupt and thus destroy the continuity7.
Because continuity does allow for changes, as long as they are gradual8, the later psychological state can ultimately be quite different from one of the earlier ones9.
Although most philosophers writing about the Psychological Continuity Account are looking at this theory as one way to explain or define personal identity, Parfit thinks that this tackles the important questions from the wrong end and that psychological continuity is in fact more important than identity1011. He does however see psychological continuity as close to being a criterion of identity12.
Parfit is also the one to introduce the distinction between psychological continuity and psychological connectedness13.
Psychological connectedness is the direct causal relation between two psychological states14, usually of two states that are temporarily not too far apart. Remembering an earlier psychological state is one possibility of this causal link that establishes psychological connectedness15. Because psychological connectedness is non-transitive (if A is psychologically connected with B and B is psychologically connected with C, it doesn’t mean that A and B are psychologically connected with each other)16, psychological connectedness is a matter of degree17.
A chain of psychological connections establishes psychological continuity18.
At this point and in preparation for the discussion in chapter III., I should mention the defining requirements of personal identity:
- The All-or-Nothing Requirement: Two items or persons either are identical or they are not. There are no options in between; identity is not a matter of degree19.
- The Transitivity Requirement: Identity has to be transitive. If A is identical to B and B is identical to C, then A is identical to C20.
- The Intrinsicness Requirement: This postulates that the identity of a person is determined without considering facts about a second person21.
- The Determinacy Requirement: Questions about personal identity must have determinate yes/no answers22.
The first two requirements are widely accepted23, whereas the third one is used as an additional requirement by Williams24, Swinburne25 and Johnston26. The fourth one is mentioned by Parfit, although he argues against it27.
III. Discussion
By contrasting the Psychological Continuity Account with the Bodily Continuity Account, it should not surprise that among philosophers and students of philosophy, the account that centres on the mind is the one more people are intuitively drawn to. If the same question was posed to a group of people who rely more on their body, let’s say a Rugby team, the preferences might tilt towards the Bodily Continuity Account.
But a decision in the matter of personal identity cannot be made by means of a straw poll. Instead, the Psychological Continuity Account has to be tested independently of its alternatives against the following possible objections, which are by no means an exhaustive enumeration:
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The informative value of thought experiments
Reading the material for this chapter felt in large parts like reading science fiction: Williams sends A and B into a machine in which A’s mind is transplanted into B’s body and vice versa28 and believes the resulting thought experiments to show that identity lies in the mind and not the body29. Parfit lets a man divide like an amoeba30, not without later reuniting these brain-halfs31 or even accomplishing a “fusion” of two previously independent persons32. Johnston writes about a brain in a vat33. (Blessed be Thomas Hobbes for sticking to the more understandable example of “Theseus’ ship”34, to which the replacement of human body cells over time even shows some resemblance35.)
I am rather sceptical about most of these thought experiments, because I fail to see what insight can be gained from them. People are not earthworms that can be divided and continue to live. We can’t build a new brain or mind out of two or more existing ones. These experiments are not only physically, technically and medically impossible3637 (and might just as likely result in the death of all persons involved were they carried out), but so far from reality that we should admit that we cannot possibly grasp their consequences. They raise plenty of questions without answering any of the pressing questions that we have38.
But while the use of these thought experiments therefore does nothing to convince me of any of the theories of personal identity, I realise that (a) this is due to my lack of capability for abstract understanding,and (b) that the use of bad examples does not discredit the theory that is to be tested. We therefore have to deal with some substantive issues of the Psychological Continuity Account:
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Inconsistency with the All-or-Nothing Requirement
The All-or-Nothing Requirement (see II.1.) is one of the requirements widely accepted by most thinkers that discuss personal identity39. It postulates that two persons are either identical or they are not40: identity cannot be a matter of degree41.
Psychological connectedness however, which in turn establishes psychological continuity42, is a matter of degree43. Parfit prefers to speak of “survival” instead of identity44 but equally says that it is a matter of degree45.
Defining personal identity through the Psychological Continuity Account which has different stages and grades could be seen as watering down the All-or-Nothing Requirement. On first sight, it seems as if one is trying to avoid the tough (possibly conceptually unanswerable) question of personal identity by moving to (psychological) continuity.
However, it is not uncommon that something that has to be decided on an all-or-nothing basis is dependant on criteria which are themselves open to different stages or degrees. For example, a person can be guilty or innocent of a certain crime. This is an All-or-Nothing Requirement. But this decision depends on some factors which are open to varying degrees, like criminal responsibility.
This criticism therefore does not stick.
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Inability to separate mind and body
Most discussions of psychological versus bodily continuity seem to assume that the two can be separated or analysed apart from each other46. Wiggins disagrees with this47, and so do I.
I rather believe that my psychological state not only relies on my brain or mind, but also on the body that houses it48. I am 35, relatively fit and undeservedly healthy and I cannot help but assume that this has an effect on my mostly energetic, optimistic and happy psychological state. If my mind was transplanted into a different body, small changes might not matter. If I am 2 cm shorter or have a different eye colour, that probably would not change my psychological state. But if I was bound to a wheelchair, I could not physically express my psychological state, my ideas, my wishes. Likewise, if I was terminally ill, I might lose quite a bit of my optimism. “Life dominates consciousness” as Karl Marx said, admittedly in a different context.
My brain removed from my body would not be the same. It would realise (if it could even survive such an operation) that it has been deprived maybe not of the ability to think and feel, but of the ability to execute and implement these thoughts and emotions. The same might happen if my brain was not removed from my body, but my body was suddenly changed (without any direct medical effect on the brain). Gregor Samsa of Franz Kafka’s Metamorphosis would almost certainly concur with this.
The psychological continuity would come to an end in such cases, which suggests that psychological continuity without any bodily support cannot exist49.
IV. Conclusion
I am inclined to side with Swinburn who declares personal identity to be “something ultimate”50 that is beyond being explained by further definitions, whether they concentrate on the Bodily Continuity Account or the Psychological Continuity Account51. If at all, identity may explain continuity, not the other way around52.
The objections raised under III.3. seem to severely discredit the Psychological Continuity Account because we lack any indication about what a brain or mind would think if it was deprived of its bodily surroundings, reducing the thought experiments used by most authors to nothing more than mere speculation.
Bibliography
Papers
Parfit, Derek (1971) “Personal Identity”, The Philosophical Review, LXXX, 3-27 (reprinted as reading 4.2 to accompany A850 Postgraduate Foundation Module in Philosophy, Milton Keynes, The Open University and quoted by the pages of the reprint).
Swinburne, R.G. (1973) “Personal Identity”, The proceedings of the Aristotelian Society, LXXIV, 231-47 (reprinted as reading 4.3 to accompany A850 Postgraduate Foundation Module in Philosophy, Milton Keynes, The Open University and quoted by the numbers of the paragraph in the reprint).
Williams, Bernard (1973) “The Self and the Future”, The problems of the Self: Philosophical Papers 1956-1972, Cambridge, Cambridge University Press (reprinted as reading 4.1 to accompany A850 Postgraduate Foundation Module in Philosophy, Milton Keynes, The Open University and quoted by the numbers of the paragraph in the reprint).
Study material
Belshaw, Chris and Price, Carolyn (year unknown) Personal Identity, A850 Postgraduate Foundation Module in Philosophy, Chapter 4, Milton Keynes, The Open University.
The internet
Olson, Eric T. (2010) “Personal Identity”, The Stanford Encyclopedia of Philosophy (Winter 2010 edition), Edward N. Zalta (editor), http://plato.stanford.edu/archives/win2010/entries/identity-personal/
The Happy Hermit 