Personal Identity

Homework

• Bring in a baby photo of yourself to next Wednesday’s lesson (you’ll find out why later…)

• Are you the same person you were 5 seconds ago?

• How do you know?

• Are you the same person you were last night?• How do you know?

• Are you the same person you were last year?• How do you know?

• Are you the same person you were when you were 11?

• How do you know?

• Are you the same person you were when you were 3?

• How do you know?

• Are you the same person you were when you were a baby?

• How do you know?

What secures our personal identity through time?

• What makes you the same person throughout your life?

• How do you know the answer to this question?

• How do other people know that you are the same person on a daily basis?

What is the problem of personal identity?

• Why is identity important: personal identity is an important issue in philosophy of mind because philosophers want to establish what it is that makes a person the ‘same’ person over a period of time. They are not interested in identity in the sense of how we see ourselves – that might be a psychological issue.

What secures our personal identity through time?

When philosophers talk about Identity they usually mean strict identity – an all-or-nothing relationship. Either identity holds, or it doesn’t. Identity to the philosopher doesn’t just mean similarity of qualities, or even identity of qualities. In fact, though, the philosophical understanding of identity is even more precise than this.

Qualitative versus Numerical Identity

1. In your groups, you need to sort the cards (sorry, you’ll have to cut them out first!) into two categories – things which are qualitatively identical and things which are numerically identical.

2. Next, you need to define, as a group, the two terms and the distinction between them.

Approaches to Identity• Philosophers are interested in two types

of identity: qualitative identity concerns things that are identical in type – such as identical things.

• Numerical identity concerns things that are single entities, but have qualities that make us refer to them in distinct ways.

• Superman and Clark Kent are numerically identical but are regarded as two separate beings.

• Philosophers are most concerned with the metaphysical issues of personal identity, not the epistemological issues.

• It’s not how we know that people are identical to themselves, but what the nature of that identity is.

Qualitative versus Numerical Identity

Qualitative Identity – holds in the case e.g. of identical toothbrushes, or other manufactured goods. These things exactly resemble each other – you can’t tell them apart. But they are separate entities – they can exist independently of each other.

Numerical identity is different to qualitative identity. It’s the sort of identity that holds where there is only one of a thing that is that thing. Numerically identical things are always the same thing even if we sometimes think of them as being different (e.g. the morning star and the evening star are both Venus.) The total number of entities is 1, and so they can’t exist independently of each other – even if they look different over time.

Philosophers are usually interested in numerical identity when considering personal identity. How can someone be the same at both t=0 and t=1 even if lots about them is different? What are the necessary and sufficient conditions for people to be the same at t=0 and t=1? The key question for Personal Identity is: How can a present person be the same as a past person?

Two Reductionist Approaches• Philosophers usually reduce personal identity to one of two basic

elements, although most accounts of what we are would have to take account of both.

• The two elements are, of course, the mind and the body.• Physical continuity argues that we identify individuals by the fact

that they are physically the same being as they were on previous occasions.

• Psychological continuity is the view that it is the continuation of our mental life by memory we identifies us as the same person.

• A number of questions arise from these two approaches. For example: How do we judge physical continuity? How can we argue that someone’s mental life continues if they suffer severe brain damage?

3rd person versus 1st person perspectives – physical versus psychological approaches

There are usually thought to be two ways of approaching the question of personal identity – the first-person approach, and the third-person approach. • The third-person approach uses the idea that physical

continuity over time is the right criterion to use for personal identity. So: is physical continuity through observation (in practice or in principle) a criterion for personal identity? Is the 3rd-person perspective sufficient to prove identity?

• There is also a first-person perspective which is non-observational. You know – or think you know – that you are the same person that you were last week. You feel you have psychological continuity because you have a strong sense of the continuity of your mental life.

Physical Continuity In the physical continuity theory a person

is judged to be the same person only if they have the same body that they did yesterday.

That is, we are ‘identical’ to ourselves on the basis of our physical characteristics.

This would be a fairly commonsensical approach: we know that our friends and family are indeed the people we think they are because they resemble them physically.

What problems might arise if we did not recognise a person as the same physical being that we knew before?

Problems with Physical Continuity• However, physical continuity can be seriously

problematised when someone’s body changes over time.

• Think about the aging process or plastic surgery. Are we the ‘same’ physically as we were when we were five? Would we be the ‘same’ if we had a drastic nose job?

• In some cases physical changes are so large that we can’t identify the person as the ‘same’ on the basis of physical appearance.

• More serious problems occur with issues such as cloning. If a clone is exactly identical to its original in a physical way, is it the ‘same’? We would have to argue both yes and no.

• A clone is the same in the sense of being an exact copy but not in being numerically the same.

The Prince and the Cobbler• John Locke raised an important problem for

physical continuity theory by distinguishing the man and the person.

• A man for Locke is a physical human being. However, a person is the same social and psychological being.

• Locke developed this distinction by using the example of the prince and the cobbler.

• Locke imagines a prince and a cobbler who have had a complete exchange of personalities or ‘ a transfer of souls’.

• Would the prince continue to be the same person if he suddenly had the mind of someone else?

• Most people would say that the answer to this question would be no. For this reason, Locke completely rejects physical continuity as an argument for personal identity.

Sydney Shoemaker Sydney Shoemaker updated Locke’s

example by considering the possibility of brain transplants.

Imagine a brain transplant between two people.

If one patient died during the transplant, who would the survivor be? Would he be the person whose body he had or the person whose mind he had?

Shoemaker rejects the idea that the body would form the simple basis of our identity because the behaviour and habits of that person would be governed by the mind of someone else.

Psychological Continuity• John Locke argued that real identity

is found in psychological continuity, not the physical continuity of the body.

• Personal identity for Locke is a matter of the continuity of consciousness from one moment to another.

• As such, identity is not a matter of the physical substance of the person, but rather the consciousness that unites the person’s different actions.

• The mind of a person is the thing that really ‘underpins’ who they are for Locke, and it is this mind that makes the different connections between their different and varied experiences.

Locke and Memory• The key to Locke’s account of

psychological continuity is memory.

• For Locke, a person is the ‘same’ person over time if they have the same ‘reservoir’ of memories.

• A person may change physical from childhood onwards, but if they have the same basic memory structure then they are the ‘same’ person.

• What problems can arise if memory is the criteria for psychological continuity?

Problems with Psychological Continuity

John Locke’s argument also seems to be commonsensical, but is open to a number of serious problems.

The most obvious is that the mind can change as drastically as the body. As we age our minds can fail as well as our bodies and memory loss would not obviously mean that we are not the ‘same’ person.

If we suffered traumatic memory loss as the result of an accident would we become someone else?

These problems mean that Locke’s account of psychological continuity is not as plausible as it may at first seem.

Thomas Reid Thomas Reid developed an objection to Locke using the

example of the ‘brave ensign’. Reid imagines an ensign (a young soldier) who stole

apples as a young boy and was flogged for it. The boy grew up to become a brave soldier who won

many medals, but still remembered stealing the apples and his violent punishment.

Many years later the ensign was an old general with a distinguished military career.

The old general had clear memories of his youth and the battles in which he won his medals.

However, the old general has absolutely no memory of being the boy who stole apples, and even his flogging has vanished from his mind.

For Reid, this example clearly shows that on Locke’s account of personal identity the general is not the same person as the boy.

However, this seems to be absurd since most people would argue that the two clearly are the same person.

Joseph Butler Joseph Butler added the further criticism

that Locke’s account of identity is circular. Butler’s argument is that remembering an

event does not constitute identity, since consciousness is the very thing that constitutes identity in the first place.

This is circular because we are already presupposing that identity exists for us to have a memory of it.

For the ensign to remember his problem with the apples means that there was already some formation of his identity at the earlier stage.

The fact of the memory does not add anything to this and so a collection of memories is not the same as a person’s identity.

Examples of Identity Problems

• Plastic Surgery.• Transformations.• Loss of memory.• Multiple Personality Disorder.• Psychoses – schizophrenia.• Fiction – e.g. Dr. Jeckyll and Mr. Hyde.

Plenary

What secures our personal identity through time?• Whether either physical or psychological continuity through time are necessary or sufficient conditions of identity.