The Philosophy of Personal Identity
Crash Course Philosophy explores the concept of personal identity, questioning what makes a person the same over time, despite changes in their body, memories, and experiences. This discussion is sparked by the fictional example of Doctor Who, whose various incarnations raise the question of whether they are all the same individual.
The Question of "Who is Who?"
The issue of personal identity isn't confined to science fiction. It arises in everyday life when we consider how much a person can change and still be considered the same individual. For example, are you the same person you were as a child? Will you be the same person in the future?
The Illusion of Constant Identity
While we tend to believe in our continuous existence from birth to death, some argue that only our name remains constant. Philosophers have long sought the "essential property" that defines personal identity and persists through time and change.
Theories of Personal Identity
Philosophers have developed various theories attempting to define what makes a person the same over time. Two prominent theories are explored below.
The Body Theory
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This theory, often held as a default position, posits that personal identity persists because you remain in the same body from birth to death.
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However, the body is constantly changing, with cells and even skeletal structures being remodeled over time.
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This raises the question: How much can your body change before you become a different person?
The Memory Theory
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Proposed by John Locke, this theory emphasizes consciousness and memory as the basis of personal identity.
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Identity persists because you retain memories of yourself at different points in time, linked together in a chain.
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Even if you don't remember every moment, you can likely remember a time when you did remember it, creating a link to that past self.
Problems with the Memory Theory
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Lack of Early Memories: We don't remember being born, so when did we become who we are?
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Memory Loss: Does a person with dementia cease to be the same person once they lose their memories?
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False Memories: Memories are not always accurate. How do inaccurate memories affect personal identity? Does having false memories make one a partially fictional person?
The Importance of Personal Identity
The question of personal identity extends beyond a mere conceptual exercise. It has practical implications for how we live our lives and interact with others.
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Obligations: If individuals are not distinct and persistent, do our obligations to them still hold?
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Expectations: Our society is built on the expectation that individuals will remain consistent, upholding promises and fulfilling responsibilities.
Why You Should Care
You rely on the expectation that others will remain the same people they were when making promises or agreements. Therefore, you have a vested interest in understanding the persistence of identity and whether it is something you need to believe in and find reasons for.