Arguments Against Personal Identity: Crash Course Philosophy #20

Summary

In this Crash Course Philosophy episode, the focus is on the concept of personal identity and its persistence over time. Scottish philosopher David Hume challenges the idea of a stable self, suggesting that the 'self' is an illusion and merely a bundle of ever-changing impressions. Contemporary philosopher Derek Parfit extends this idea, proposing that personal identity is not a fixed entity but a series of psychological connections that evolve. The episode explores thought experiments, such as teleportation to Mars, to question the continuity of identity and its implications for responsibility, promises, and relationships.

Takeaways

• 🧠 David Hume, an 18th-century Scottish philosopher, argued that the concept of a persistent self is an illusion and that there is no single, unchanging 'you' from birth to death.
• 🤔 The idea of personal identity is complex and can be influenced by various factors such as relationships, interests, skills, and societal labels.
• 🧬 The body theory suggests that personal identity is preserved by occupying the same physical body over time, while John Locke's memory theory posits that memories are the key to maintaining personal identity.
• 🤝 Derek Parfit, a contemporary British philosopher, agrees with Hume that personal identity does not persist over time but introduces the concept of psychological connectedness to explain our sense of self.
• 🔄 Parfit's chainmail analogy illustrates how our personal identity is made up of interconnected experiences and memories that evolve over time, with some links becoming weaker and others stronger.
• 🚀 Parfit's thought experiment involving a machine that atomizes and recreates a person on Mars challenges the notion of personal identity and raises questions about what it means to be the 'same' person.
• 💍 The concept of marriage vows and lifelong commitments is reconsidered in light of the idea that people change over time, suggesting that promises made in the past may not necessarily bind the person you are today.
• 🤷‍♂️ The question of personal responsibility is complicated by the lack of a constant self, as it becomes unclear how one can be held accountable for actions taken by a 'previous' version of themselves.
• 🤗 Parfit suggests that our connections to past selves through psychological links are what give us a sense of continuity and relevance, allowing us to maintain relationships and commitments despite change.
• 🌐 The philosophical exploration of personal identity has practical implications for how we understand and navigate our relationships, promises, and sense of self in a world where change is constant.

Q & A

What is the main argument David Hume presents about personal identity?

David Hume argues that the idea of the self does not persist over time, suggesting that there is no single, constant 'you' from birth to death. He posits that the concept of the self is an illusion.

How does Hume describe the 'self'?

Hume describes the 'self' as a bundle of impressions, which includes various aspects such as the body, mind, emotions, preferences, memories, and labels imposed by others. He suggests that there is no single underlying thing that holds all these aspects together.

What is the significance of Derek Parfit's thought experiment involving a machine that breaks down and recreates a person on Mars?

Derek Parfit's thought experiment is significant as it challenges the concept of personal identity by questioning whether the recreated person on Mars is the same individual as the original. It explores the idea of identity in terms of physical replication and psychological continuity.

According to Parfit, what is the relationship between personal identity and psychological connectedness?

Parfit suggests that although there isn't a singular, persistent 'you' from birth to death, each person has a psychological connectedness with their selves over time. This connection is likened to a chainmail, where links represent psychological connections that persist or fade over time.

How does Parfit's theory of survival through psychological connectedness affect our understanding of promises and responsibilities?

Parfit's theory implies that the degree of responsibility and obligation one has corresponds to the degree of psychological connection to the person who made the promise or incurred the responsibility. This means that if one has significantly changed, they may not bear the same responsibility for past actions or promises.

What is the body theory of personal identity mentioned in the script?

The body theory of personal identity is the view that a person remains the same over time because they occupy the same body from birth to death. This theory is one of the main possibilities considered for preserving personal identity.

What is John Locke's memory theory and how does it relate to personal identity?

John Locke's memory theory posits that your memories are what make you the same person over time. According to this theory, you are 'you' because you remember being 'you' in the past, linking your current self to your past self through memory.

How does the script address the issue of personal responsibility in the context of changing identity?

The script discusses personal responsibility in the context of changing identity by exploring how one's accountability for their actions may be affected if they are not the same person as they were before. It raises questions about the validity of holding someone accountable for their past actions if their identity is not constant.

What is the significance of the 'Thought Bubble' segment in the script?

The 'Thought Bubble' segment serves as a device to present philosophical thought experiments and ideas in a more engaging and accessible manner. It is used to delve deeper into concepts like personal identity and the implications of identity change.

How does the script connect philosophical discussions of personal identity to everyday life?

The script connects philosophical discussions of personal identity to everyday life by using relatable examples such as marriage vows, friendships, and personal growth. It shows how these philosophical concepts can influence our understanding of relationships and personal responsibilities.

Outlines

00:00

🧠 The Illusion of Self: David Hume's Philosophy

This paragraph introduces the concept of personal identity and the idea that our sense of self is not as fixed as we might believe. It presents the 18th-century Scottish philosopher David Hume's argument that the self is not a persistent entity over time, but rather an illusion. Hume suggests that we are constantly changing bundles of impressions, including our body, mind, emotions, and memories. The paragraph explores the implications of this view on personal responsibility, relationships, and the very notion of being the same person over time. It also touches on the philosophical theories of body and memory as markers of personal identity, which Hume critiques for their inability to account for the constant flux of human experience.

05:01

🔗 Psychological Connectedness and Personal Identity

The second paragraph delves into Derek Parfit's extension of Hume's ideas, focusing on the psychological connectedness that gives us a sense of continuity over time. Parfit uses the analogy of chainmail to illustrate how our identity is composed of interconnected experiences and memories that evolve and change. He argues that while we are not the same person throughout our lives, certain psychological connections to our past selves persist, forming a relevant sense of self. The paragraph discusses how this theory can affect our understanding of promises, obligations, and the relevance of long-term commitments like marriage vows. It also highlights the importance of updating our relationships to reflect the current versions of the people we interact with, emphasizing the philosophical relevance to personal growth and interpersonal connections.

Keywords

💡Identity

Identity in the context of the video refers to the various roles, characteristics, and attributes that define an individual. It is central to the theme as it explores how these identities are not fixed but change over time. The script mentions identities such as 'sister,' 'daughter,' 'colleague,' and 'mentor,' illustrating the diverse ways people perceive themselves and are perceived by others.

💡David Hume

David Hume is an 18th-century Scottish philosopher highlighted in the video for his skepticism about the concept of a persistent self. His view challenges the idea of a stable identity, suggesting that the 'self' is an illusion and does not persist over time, which is a key philosophical argument in the discussion about personal identity.

💡Self

The concept of 'self' in the video is explored as something that is not constant but an ever-changing collection of experiences and properties. It ties into the main theme by questioning the traditional understanding of a stable, unchanging self. The video uses Hume's argument that the self is a 'bundle of impressions' to illustrate this idea.

💡Personal Identity

Personal identity is a central theme of the video, focusing on the philosophical inquiry into what makes a person the same individual over time. It is discussed in relation to theories like body theory and memory theory, and it is challenged by Hume's and Parfit's ideas that identity is not a fixed entity.

💡Bundle Theory

Bundle theory, as proposed by Hume, suggests that the self is not a single, unified entity but a collection or bundle of different properties like perceptions, thoughts, and feelings. This theory is crucial in the video's exploration of identity, as it directly contradicts the notion of a stable, continuous self.

💡Derek Parfit

Derek Parfit is a contemporary British philosopher mentioned in the video for his thought experiment regarding personal identity. Parfit's work is significant as it extends Hume's ideas, suggesting that personal identity is not about a single, unchanging self but about psychological connectedness over time.

💡Psychological Connectedness

Psychological connectedness, as introduced by Parfit, refers to the continuity of consciousness and memory that links a person's experiences over time. This concept is pivotal in the video's discussion of identity, as it offers an alternative to the traditional view of a static self, emphasizing the evolving nature of personal identity.

💡Memory Theory

Memory theory, associated with John Locke, posits that personal identity is maintained through the continuity of memory. The video critiques this theory by showing its limitations and introducing alternative views, thus contributing to the broader debate on what constitutes personal identity.

💡Body Theory

Body theory is a concept that equates personal identity with the physical continuity of the body from birth to death. The video discusses this theory as one of the traditional approaches to understanding identity but also points out its flaws, leading to a deeper philosophical inquiry.

💡Responsibility

Responsibility in the video is discussed in the context of personal identity and the implications of the changing self. It raises questions about accountability for one's actions if the self is not a constant entity. The video uses this concept to explore the practical implications of philosophical theories on identity.

💡Survival

Survival, as used by Parfit, refers to the persistence of certain elements of personal identity over time, despite the lack of a continuous, unchanging self. The video uses this concept to discuss how identity can be relevant and meaningful even if it is not static, thus connecting philosophical ideas to personal experiences.

Highlights

David Hume argues that the idea of the self doesn't persist over time and is an illusion.

Hume suggests that there is no single, constant 'you' from birth to death.

The concept of self is a bundle of impressions, including body, mind, emotions, and memories.

Hume's view implies that personal identity is not fixed and can be both liberating and terrifying.

The implications of Hume's philosophy on personal responsibility and the constancy of relationships are explored.

Derek Parfit's thought experiment questions the nature of personal identity through a hypothetical teleportation scenario.

Parfit agrees with Hume that personal identity is not preserved over time but introduces the concept of psychological connectedness.

Parfit's chainmail analogy explains how personal identity is composed of interconnected experiences and memories.

The theory of survival through psychological connectedness suggests that parts of our identity persist over time.

Parfit challenges the notion of lifelong promises and obligations, proposing a more fluid understanding of personal responsibility.

The concept of marriage vows is reexamined in light of the changing nature of personal identity.

Philosophy provides insights into understanding ourselves and maintaining close relationships despite personal changes.

The episode concludes by emphasizing the practical implications of philosophical theories on personal identity.

Next episode's focus on the term 'person' is teased, indicating a deeper dive into the concept of identity.

The episode is sponsored by Squarespace, which offers a platform for creating professional websites without coding.

Crash Course Philosophy is produced in association with PBS Digital Studios, promoting a variety of educational content.

Transcripts

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In your day-to-day life, you probably assume a whole bunch of different identities.

You might be a sister to your brother, a daughter to your parents, a colleague to your co-worker.

A mentor to the kids you teach.

Or you might think of your identity as being based on your interests, your skills, or things like your gender or ethnicity.

Whatever they are, I’ll bet that you think of your identities as being pretty fixed.

Stable. And you like ‘em that way.

And if that’s the case, I’d like you to meet this guy: 18th century Scottish philosopher David Hume.

Because, he says you’re wrong.

Hume argued that the idea of the self doesn’t persist over time.

He said there is no you that is the same person from birth to death.

He said the concept of the self is just an illusion.

This could be either liberating or terrifying, depending on how you look at it.

I mean, if you don’t have an identity, you don’t have to worry about identity theft.

But what does it mean for my understanding of myself, and for the people I love, if there is no single, constant me?

If that’s the case, then the person I’m married to is literally not the person I fell in love with, or made those vows to.

Which would suggest that I don’t need to keep those vows, and neither does she.

And what about personal responsibility?

How can you hold someone accountable for their actions, if they’re not the same person now that they were before?

And how can you be responsible for something that you did, if you’re always changing?

This is gonna get dicey.

[Theme Music]

If you joined me last time when we talked about personal identity, you’ll remember that we

considered two main possibilities for what might preserve “you” as the same person over time.

One approach was the body theory, the sort of go-to view of things, which holds that

you remain “you” over time, because you just occupy the same body from birth to death.

And the other was John Locke’s memory theory,

the view that your memories are what makes you the same person over time:

I’m me, because I remember being me in the past.

But both of these models have some problems.

No matter how much we want the idea of permanent, persistent selves to be a thing, David Hume said that they just aren’t.

For him, it was really a no-brainer.

If having a certain identity means possessing the same set of properties, he said, then

how could anyone really maintain the same identity from one moment to the next?

I clearly don’t share all the same properties as my childhood self – or even my self before I shaved today –

so Hume would say that it’s silly to pretend I’m still me.

But I feel like me. So what did Hume think was going on?

Hume said that the so-called “self” is just a bundle of impressions, consisting of a zillion different things –

my body, my mind, emotions, preferences, memories, even labels that are imposed on me by others.

Think of a box – and say it’s marked “Hank” – and then put in that box everything that makes me who I am.

My DNA, mannerisms, political leanings, my glasses, the relationships I have with others, the various roles I hold.

Then, you take away the box.

Hume’s point is, the “self” is just shorthand for all the junk in the box.

And the fact that there is no box points out that there’s no single underlying thing that holds it all together.

And meanwhile, some of the stuff in the bundle goes away, and new stuff shows up.

So, if you look at the bundle that is me now, and compare it with the bundle that my mom

and dad brought home from the hospital,

they would be almost completely different.

So Hume said we’re all just ever-changing bundles of impressions that our minds are

fooled into thinking of as constant,

because they’re packaged in these fleshy receptacles that basically look the same from one day to the next.

To explore this some more, let’s bounce over to the Thought Bubble for some Flash Philosophy.

Contemporary British philosopher Derek Parfit, probably after watching a Star Trek marathon, posed this thought experiment.

Imagine a machine that breaks you down atom-by-atom, copies all of that information, and transmits it to Mars, at the speed of light.

Once that information gets to Mars, another machine uses it to re-create you, atom by atom,

using copies of the same organic stuff that you were composed of here on earth.

The person who wakes up on Mars has all the same memories and personality as you did – and that person thinks it’s you.

So here’s the question – is this space travel?

Did you travel to Mars?

Is the transported person really you?

Or was a new being created that just happens to correspond to you, atom by atom, thought by thought?

Now, consider this: What if a new version of the machine is created, so that now, instead of destroying your body,

it can simply be scanned, and all the information can be re-created on Mars, but the you here on earth still exists.

Now did you travel? Or were you just replicated?

If you’re here on earth, are you also on Mars?

Wow…uh, yeah, thanks, Thought Bubble… I think.

Parfit agrees with Hume that there isn’t such a thing as personal identity over time.

So, he says, in either case, you didn’t travel through space –

that’s just a new you that shows up on Mars, whether the old you was destroyed or still exists.

And you know what?

Even if you hopped on a spaceship and flew to Mars the old-fashioned way, it’d still be a new you that arrives,

because you would’ve experienced all sorts of changes during the trip.

But the thing is, Parfit thought Hume missed a really important point.

Even though there isn’t a singular you from birth to death,

Parfit says that each of us has a psychological connectedness with our selves over time.

Think about your life as being like a piece of chainmail.

The mesh that is your personal identity is made up of lots of separate chains,

and those chains intersect at certain points, to make up the chain mail.

As you follow the timeline of one particular set of links, new links are being created that add to the chain.

And as time passes, the links that are farther back in your past slowly start to drop off,

as they lose their psychological connection to you.

So, when you stopped loving Dora the Explorer, that link dropped away.

And when you discovered that you totally love philosophy, a new link was created.

But some chains intersect with that other chain, and they have links that persist for

a long time, like the love you have for your parents.

So Parfit says that, sure, I’m not the same person that I was in elementary school.

And I won’t be the same person when I die.

I’m not even really the same person I was when I started this sentence, because every experience changes us, at least a little.

But parts of me survive the passage of time, because they’re psychologically connected to my previous selves.

And survival is what’s important, for Parfit.

As long as enough of the elements of you persist, you see yourself as relevantly the same.

But not for a whole lifetime. Parfit would say none of the you that existed at birth is still around –

your physical matter is almost all different, and you have no memory of that time, and your preferences have completely changed.

Baby You has not survived. But some of Last Year You probably has.

And Parfit seems to have hit on an important insight here.

Think about what you do when you catch up with an old friend.

The first thing you do is ask what’s happened since you last spoke.

What you’re doing, without really thinking about it, is recognizing that you both have changed.

If the changes are big, then your friend could seem like a stranger at first.

So, when it’s someone you care about, you take the time to reacquaint yourself with this new person.

Because, you recognize the need to always know the most updated version of that person.

But the opposite can also happen.

Think about that aunt you only see at Christmas, who still pinches your cheek and gives you a new American Girl doll every year.

She probably knew what you loved when you were 10.

But she doesn’t know the current you.

The version of you she’s shopping for at Christmas doesn’t exist anymore.

But since you rarely see each other, and you haven’t made the effort to know the new yous,

you’re both looking past each other in that painfully awkward way that makes holidays with relatives so special.

So now let’s think back to the question we discussed earlier –

if I’m not the same me over time, how do I make sense of promises, obligations, and responsibilities?

Parfit’s theory gives us an answer! Your degree of responsibility and obligation corresponds

to your degree of connection to the person who made the promise or incurred the responsibility.

So, if you were a kindergarten bully who grew up to be a totally sweet guy who would never

bully anyone, you don’t need to feel any guilt.

You’re not that person anymore – you don’t bear responsibility for his actions.

Likewise, if you and your childhood bestie pinkie-swore to be each other’s maids of honor when you grew up,

but now the two of you have nothing in common, you’re off the hook for that promise.

Now about those marriage vows?

Well, a promise that lasts a lifetime doesn’t really make sense, in Parfit’s view.

And there are actually people, using this line of reasoning, who argue that marriage contracts should be temporary,

with the option of renewal – kind of like a cell phone plan.

But others have said that marriage vows can actually stay relevant, even after a lifetime of changes.

Over the years, you and your spouse both change, and become different people.

But, these thinkers point out, you may be constantly reaffirming the promises you made on your wedding day.

So, a wedding vow isn’t a promise you made years ago, when you were a completely different person.

It’s a promise you made this morning, when you took out the trash and cleaned up the hairball the cat left on the rug.

Why is it always on the rug?

So clearly, we’re not talking about Batman, or science fiction, or hypothetical trips to Mars anymore.

We’re talking about how philosophy can teach you about yourself, and the people you care about,

and how you can continue to know them and be close to them over time.

Today we continued our exploration of personal identity, learning about Hume’s bundle theory

and Parfit’s theory of survival through psychological connectedness.

Next time, we’re going to address a term that we’ve been taking for granted throughout

this whole discussion: person.

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