The Self and its Identity

Identity

Two things are identical if they are one and the same. For example, Superman is identical (i.e., is) Clark Kent; the Queen Mary and the ship that was launched on September 26, 1934 in Clydebank, Scotland are one and the same ship.

We think of identity a-temporally and temporally:

• a-temporal identity, e.g. 3+2 = 5.
• temporal identity, which can be thought of as synchronic or diachronic:
• synchronic identity: what makes X,  X at a time t, e.g. what makes two stretches of road the same road?
• diachronic identity: what makes x at t₁ the identical x at t₂, e.g. what makes a ship yesterday the same ship as today?

Here we focus on the identity of the self though time.

What makes me the same individual self who started this sentence? Here are some options and their problems.

My body

Sounds plausible, as that’s how we determine the identity of others. So, perhaps one should say that I am my body and I exist as long as my body lives. This leaves the problem of deciding what makes my body at 2:00 one and the same as my body at 2:01. Suppose, however, that we have solved that.

Note: I might exist as a person only for part of my life, for example, as long as I have consciousness; being a person then would then be a transient property. At 3 weeks after conception, when I had a 2 chamber heart and pharyngeal arches like a fish, and no neural system even remotely associated with conscious thought, that animal was me.

Problems

· In case of brain transplant, it would seem that the person would follow the brain, not the body. In this case, what matters is the donor of the brain, not the recipient.

· When I wake up, I seem to be able to know it’s me without looking at my body at all.

So, perhaps we should say

My brain

Sounds plausible. However,

Problem:

· Fission: suppose one performs hemispherectomy on me, and then transplants the left hemisphere in body X and the right hemisphere in body Y. Who of these two is me? They are two and therefore they cannot both be one and the same with me, otherwise they would not be two but one.

· Perhaps it could be possible to remove my consciousness from my brain and place it in another brain, or in a machine. But then it looks as if I would follow my consciousness, not my brain.

So, perhaps we should say that the persistence through time of my individual self is given by

My consciousness

Sounds plausible. I don’t need to look at my body to know it’s me because I have access to my consciousness; and I do not need to know I even have a brain to know it’s me. So, A and B are one and the same if they share the same consciousness. But this seems just to push the problem one step back; for, what makes consciousness X at 2:15 one and the same as consciousness Y at 2:00? What is the link that makes these two consciousnesses one and the same?

Memory, the fact that Y remembers X’s thoughts. This is Locke’s memory theory of personal identity (PI).

Note: memory is not only a criterion of PI; it is also constitutive of it.

Problems:

· we need to distinguish really remembering from merely seeming to remember. I may believe that I remember placing the keys on the table when in reality I am just misremembering, as George IV on his deathbed. Could one say that George IV (on his death bed) doesn’t really remember being at Waterloo because George IV (at the time of the battle of Waterloo) wasn’t there? No. In the memory theory the lack of real Waterloo-memory makes George IV a person who was not at Waterloo, and therefore we cannot say that George IV’s memory on his deathbed is not a real one because he wasn’t at Waterloo.

Solution: real memory must have the appropriate causal link to the thing or event remembered.

· Reid's story: A is memory-linked to B and B to C; however, A is not memory-linked to C. Hence, although A=B and B=C, it is not true that A=C. This contravenes the transitivity of identity, which says that if A=B and B=C, then A=C.

Solution: we may add transitivity: if A is memory-linked to B and B to C, then A is identical to C even if A is not (directly) memory-linked to C.

· memory can be irretrievably lost. So if A has a memory disorder and has no memory of being B, then A is not one and the same as B. But this seems strange: the reason we feel sorry for A is that he does not remember his past!

Perhaps memory is too demanding a requirement. Perhaps we should say that the persistence through time of my individual self is given by

My mind

Sounds plausible. But what makes mind A at 2:00 one and the same as mind B at 2:01?

Psychological continuity: the fact that there is psychological continuity between A and B. This continuity consists in psychological causation: B’s mental states are caused (for the most part) by A’s.

Problems:

· Was I not that 1 week old fetus without any consciousness (insufficient neurological structure) or that unconscious living organism after the horrible car accident?

· Hemispherectomy plus transplant; the two half brains wake up with the right memories ( type of psychological continuity) as memories are distributed in the brain. So we have the fission problem again.

Perhaps, my identity through time is given by:

Psychological features: the individual who started this sentence has the same psychological features (same personality, basic beliefs, values, etc.) as the one who finished it. Note that “same” here means ‘very similar’.

Problems:

· How about two people who have very similar psychological traits? It does not make them one and the same

· One could suddenly change one’s psychological traits because of traumatic event; think of St. Paul’s conversion.

So, similarity of psychological traits is neither necessary nor sufficient for the identity of the self.

Perhaps, we should appeal to:

The soul (assuming that such a thing exists):

Problem:

Since the soul is unobservable, how do I know that I’m the same individual, the same self, as 5 minutes ago?

Possible answer: Because the identity of the body entails the identity of the soul: one and the same body is attached to one and the same soul. But how do I know that, given that the soul is unobservable?

Perhaps my identity is a fabrication:

Narrative Theory

All the theories discussed above make the assumption that PI is real: my personal identity is what it is independently of what I may think about it. However, perhaps my mind is the result of the activity of semi-independent but connected modules, each performing its function without any sort of master module (the seat of the self) coordinating the whole, much like an ant colony is made up of specialized ants each doing its task. More modestly, in light of commissurotomy, am I sure that my brain is associated with one individual only? Perhaps what seems one person is just the result of a story on the part of the left hemisphere: the unity of consciousness is not a matter of ‘oneness’ but of representational coherence. If so, one might argue that my PI just amounts to a story, a story that may contain glaring falsehoods but which provides unity, much as the standard narrative about our country provides a unifying national identity.