Greg Detre
@ 11.30 on Thursday, 25 January, 2001
Lucy Allais, History of Philosophy II
Talk of tele-transporters, commisurotomies and torture stems from Locke�s original discussion of personal identity in Book II, Chapter XXVII in his Essay Concerning Human Understanding, where he attempts to pin down what we mean when we talk of a �person� and their identity. Locke�s formulation can be described as a psychological state theory of personal identity, because he depends on the psychological criteria of consciousness and memory. It is worth remembering that Locke would like to be able to apply his conclusions here to support and refine the British legal system�s concepts of moral responsibility and criminality since this could be seen to affect the criteria he chooses.
Lowe employs a hybrid terminology borrowed from P. F. Strawson and Geach to explain what is meant by a �criterion of identity�, a term introduced after Locke wrote his Essay. He differentiates between a criterion of application and a criterion of identity. A criterion of application is �a principle determining to which individuals the general term in question is correctly applicable�. For instance, we might have a criterion of application for �green� which allows us to pick out all the green things in the room. Lowe chooses not to get bogged down in ensuing discussions of vagueness when we try to determine exactly which items are green, and which are a greeny sort of blue, say. A criterion of identity is a �principle determining the conditions under which one individual to which the term is applicable is the same as another�.
To understand Locke�s theory of personal identity, we need to first understand what he means by a person. He builds up to this, by first defining parcels of matter and then living organisms. A �parcel of matter� is simply the matter it is comprised of. If we remove or add the least portion to it, it becomes a different parcel of matter. This claim makes more sense in Locke�s atomist terms than to a modern scientific perspective, but it is clear. Because living organisms eat, excrete and are continually losing and gaining atoms, a similar sort of criterion will not work. Instead, Locke points to their biological processes as their distinguishing feature. In the case of a �person�, as we might want to use the term in a legal sense, we need to highlight their status as a moral agent. Locke describes a person as a rational, self-conscious being.
It seems to follow quite nicely then, that what distinguishes and identifies a person lies in this faculty of rational self-consciousness. Though Locke doesn�t put it in these terms, he is usually described as pointing to the �stream of consciousness� (James, 1890???) as the individual thread that runs through each person�s life. But, attractive and clean as this seems, it cannot account for the complications of personal identity that it needs to.
Williams presents a clear-headed and persuasive pair of thought experiments, designed to show that from opposing perspectives, our intuition leads us in opposing directions. For the sake of employing our intuition in his thought experiments, he is adopting almost an operationalist definition of the self: if we are especially concerned to avoid bad things happening to one body (or desire to have good things happen to it) as opposed to another when faced with an unavoidable choice, then we are indicating that that is the body we think houses our self, i.e. that that is us.
In the first experiment, two people�s brains are effectively swapped, and then an adjudicator tortures one and rewards the other with �100,000. Beforehand, both participants are required to specify which body they would like to be rewarded. Williams examines the case where both participants choose the alternate body to be rewarded and then the case where both participants choose their original body to be rewarded. He then discusses how cheated, justified, lucky or resigned each person feels, depending on whether or not the adjudicator had adhered to their wishes. In his description, the brain-trade is assumed to have effected a mutual transfer of memories, personality, experiences, feelings and sense of self. He is highly plausible.
In the companion thought experiment, Williams takes a lone participant and threatens him with torture. We are given to assume that these volunteers are drawn from the same non-profit organisation that supplied strong-minded, hands-on philosophers from before. Williams methodically and demonically proceeds through six steps:
1. Volunteer A�s memories are wiped
2. �other
3. A�s memories and experiences are filled with artificial, specially-designed memories
4. These memories are now replaced by the memories of a real person
5. This real person is revealed to be standing just outside the room. Using the patented Brain-O-Matic Mark II, Williams is able to map the structure and organisation of the two volunteers� brains and swap them
6. The body of one of the volunteers is destroyed.
Let us assume that we are placed in A�s shoes, and asked to write on a piece of paper beforehand whether we would like A or B�s body to be tortured. Clearly, we would prefer B to be tortured if none of the steps are to be carried out. If we are to remain consistent with the views espoused in the first experiment, then we have to say that by the time all the steps have been carried out, we would now be happier for A to be tortured, since we believe that our self will have fled across to inhabit B�s body. It is reasonable to ask then, where in the 6-step procedure the self migrated, i.e. at what point we should elect a different body as the object of torture.
Variations on this experiment have been considered by a number of philosophers. Swinburne prefers to talk in terms of split brain experiments (or commisurotomies) along similar lines, where half of A�s brain is spliced in to replace half of B�s brain, and supposedly wired in. In B�s body, containing half of B�s brain and half of A�s brain, is it A or B whose self remains? If we were A, would we want A or B�s body to be tortured? He identifies four possibilities:
1. B�s body is still occupied by B�s self
2. B�s body is now occupied by A�s self
3. B�s body does not contain either A or B�s self
4. B�s body contains both A and B�s selves
Swinburne wants to reject this last possibility out of hand. When put in these terms, it highlights certain assumptions that Williams is encouraging us to make. Both are concerned with the first two possibilities, that the resulting body is either A�s self or B�s self. They both realise that my personality might be lost along the way, but if so, they assume, I wouldn�t really care about the subsequent torture since I would be effectively dead, though my body lives on.
Both assume that such technology could exist, though obviously they don�t speculate about whether or not it will be invented. It seems more sensible to think that the devil lies in the details � how exactly would the amnesia operation be carried out? If it involves a sledgehammer, that will have very different results to cutting every single synapse in the brain, for instance. Yet, by glossing over these as details, they are able to discuss the problem in a quite unhelpfully broad way. We should first dispel the myth of a dualist-sounding self that inhabits bodies like a parasite clinging to the webs of our brains � in a modern materialist conception, this parasite is not immaterial, yet we can�t point to a chunk of brain that it consists of � rather, it is the structure of our brains, the abstract pattern of synaptic connectivity, or �functional organisation�, that makes up this self.
Moreover, the self being discussed is, more or less, the Cartesian res cogitans, an all-or-nothing me-ness that consists of my patterns of mental activity preserved in memory through time. There is no real discussion that the two selves could merge or mingle at all. Or, that if my memories are slowly eroded, my self is literally shrivelling. What makes me a person, with all the rights entailed, is the richness of my consciousness. If the process of turning me into an amnesic is a gradual one, then along the way I am losing my self. My self changes with every new or lost memory � Locke�s conception, though it can be criticised on certain grounds, is actually quite flexible here.
It seems to me that Williams and Swinburne suffer from a misconception of personal identity. Rather than assuming that our self can be imagined like a ball that is passed from body to body, and is held by one or the other, it makes more sense to imagine a candle-flame that can be passed to as many other candles as you like. It is meaningless to ask �Which candle holds the original flame?� The original candle has an excellent claim to this original flame, assuming it is still burning, but on reflection, there is no reason to consider that it has a stronger claim than any of the other candles. Admittedly, the flame has burnt in it for the longest continuous time, but if we assume that everything essential and characterisable about that flame has been duplicated perfectly and is now indistinguishable from all the other flames, then we must answer that all of the candles hold the flame. In the case of the self, we are assuming that our tele-transporter is capturing and transferring whatever substrate to the self it is that is usually instantiated in our brains. If this is so, then we must say that every duplicate is me, at the instant of duplication. From that moment onwards, their paths diverge and they take on different personal identities with different memories and experiences, but �I� am all of them, and no more one than any other. The same can be said for the two amoeba resulting from a single fission.
The Christian Locke probably wouldn�t have liked it, but we can quite easily interpret his position as allowing for a fission of the self in this way, if we look to the continuity of memory and experience as the thread running through our personal identity.
psychological continuity is better
than body state theories
discuss body state theory of personal identity
define synchronic/diachronic
These synchronic experiments work well as �intuition pumps�, to use Dennett�s phrase, which is probably our best source of verification in the absence of futuristic technology and a mad scientist with no compunction to actually try this with real people. But diachronic thought experiments are probably more useful and insightful in devising theories.
I would like to suggest a stricter criterion of identity than Locke�s, analogous to his criterion of identity of a lump of matter
thus with every change in memory, i.e. effectively every moment, we are a different self.
how does this help?
what unites our self through time???
what makes us have especial
sympathy towards our future self as opposed to another human being???
maybe it�s just like the fact that we�re similarly prejudiced in favour of people close to us, with whom we�ve shared experiences or empathised in the past
what does/did/would Hume say?