PHILOSOPHY - Mind: Mind-Body Dualism [HD]

Summary

In this philosophical discussion, Alex Byrne from MIT explores the concept of mind-body dualism, the idea that we are not merely physical entities but possess immaterial minds or souls. Byrne introduces the argument with a focus on its implications for the possibility of life after death. Drawing on the work of philosopher Saul Kripke, Byrne presents a simplified version of the Cartesian dualism argument, using the distinction between contingent and necessary truths to argue that one's identity is not identical to their physical body, suggesting the potential for a non-physical aspect of existence.

Takeaways

• 🎓 Alex Byrne, a philosophy professor at MIT, introduces the concept of mind-body dualism, which posits that the mind is not a physical entity but rather an immaterial one.
• 🧠 The mind-body dualism argument is significant for those who believe in the possibility of life after death, as it suggests that the mind could exist independently of the physical body.
• 🗣️ Rene Descartes, a 17th-century philosopher, is a prominent advocate for mind-body dualism, sometimes referred to as 'Cartesian dualism', which he explored in 'Meditations on First Philosophy'.
• 📚 The argument presented is a modern variant of Descartes's original, simplified by philosopher Saul Kripke in his book 'Naming and Necessity'.
• 🤔 The argument hinges on the distinction between contingent truths (which could have been otherwise) and necessary truths (which could not have been otherwise).
• 👤 It is proposed that while you and your physical body ('Bert') are closely connected, you are not identical to Bert, suggesting the mind and body are distinct entities.
• 🔍 The argument uses a thought experiment where one imagines existing without a body (disembodied) or with a different body ('Bertha'), suggesting the mind's existence does not depend on Bert's existence.
• 🚫 The concept of 'modus tollens', a logical rule of inference, is used to deduce that if it's possible for you to exist without Bert, then you cannot be identical to Bert.
• 🌐 The script challenges the viewer to consider the nature of personal identity and the relationship between the mind and the physical world.
• 📖 The discussion is part of a series that aims to explore philosophical arguments in an accessible manner, with the potential for future episodes to cover additional topics like the existence of God.

Q & A

What is mind-body dualism?

Mind-body dualism is the philosophical view that the mind and the body are distinct types of entities, where the mind is non-physical or immaterial, and the body is physical.

Why is the concept of mind-body dualism important?

The concept is important because if the mind is not a physical thing, it implies that the mind could potentially exist independently of the body, which has implications for the possibility of life after death and immortality.

Who is Rene Descartes and why is he significant in the context of mind-body dualism?

Rene Descartes was a 17th-century philosopher who is most famously associated with mind-body dualism, sometimes referred to as Cartesian dualism. He is significant because he provided a philosophical argument for the existence of an immaterial mind separate from the physical body.

What is the difference between truths that could have been false and truths that could not have been false?

Truths that could have been false are contingent, meaning they depend on certain conditions or circumstances that might have been different. Truths that could not have been false are necessary, meaning they are true in all possible circumstances, such as logical truths or truths of identity.

How does Saul Kripke's argument relate to Descartes' original argument for dualism?

Saul Kripke's argument is a variant of Descartes' original argument for dualism. Kripke's version simplifies and modernizes the argument, making it accessible for contemporary philosophical discussion while maintaining the core idea of the distinction between the mind and the body.

What is the argument's conclusion regarding the relationship between the individual and their physical body?

The argument concludes that the individual is not identical to their physical body, suggesting that the individual (the mind) could exist without the body (Bert), which supports the dualist view.

What is the first premise of the argument presented in the script?

The first premise is that if it's true that you are Bert (your physical body), then it could not have been false that you are Bert, meaning that your identity as Bert is a necessary truth.

What is the second premise of the argument?

The second premise is that it could have been false that you are Bert, based on the possibility of your existence without Bert, such as being disembodied or having a different body.

How does the argument use the concept of 'modus tollens' to reach its conclusion?

The argument uses 'modus tollens', a logical inference rule, by presenting two premises: 'If P, then Q' and 'not Q', which logically imply 'not P'. In this case, 'P' is the statement 'you are Bert', and 'Q' is 'it could not have been false that you are Bert'. Since 'not Q' is true (it could have been false that you are Bert), 'modus tollens' leads to 'not P', concluding that you are not Bert.

What is the significance of the distinction between truths about language and truths about the world in the argument?

The distinction is significant because the argument relies on the idea that truths about identity (like being Barack Obama) are necessary and not about language. This distinction helps to establish that the identity of the mind with the body (Bert) is contingent, not necessary, which supports the dualist position.

How does the script use the example of Barack Obama to illustrate the concept of necessary truths?

The script uses the example to show that some truths, like the identity of a person, are necessary because they are true in all possible worlds. It contrasts this with contingent truths, which could have been different under different circumstances.

Outlines

00:00

🧠 Introduction to Mind-Body Dualism

Alex Byrne introduces the concept of mind-body dualism, the philosophical view that the mind is a non-physical entity separate from the physical body. Byrne explains that if we are not physical, we might be immaterial minds or souls. This has implications for the possibility of life after death, as physical bodies are destructible. Descartes, a famous proponent of dualism, argued for the immortality of the soul in his work 'Meditations on First Philosophy.' Byrne will present a simplified version of Descartes's argument as presented by Saul Kripke, focusing on the distinction between truths that could have been false and those that could not.

05:02

🤔 The Argument for Dualism

The argument for dualism is presented by contrasting truths that could have been different from those that are necessarily true. Byrne uses the example of Barack Obama to illustrate that some truths, like identity, are necessarily true and could not have been false. Applying this to the mind-body relationship, Byrne suggests that while it might be true that 'you are Bert' (your body), it could have been false because you could have existed without Bert. This leads to the conclusion that you are not identical to your body, supporting the dualist view that the mind is a distinct, non-physical entity.

Keywords

💡Mind-Body Dualism

Mind-body dualism is the philosophical view that the mind and the body are distinct and separable entities. In the context of the video, this concept is central to the argument that we are not merely physical beings. The video explains that if we are not physical, we might be considered immaterial minds or souls, suggesting that the universe contains both physical bodies (like brains) and non-physical minds. The video uses the example of the connection between 'you' and your physical body 'Bert' to argue that they are not identical, supporting the dualist position.

💡Immaterial Minds

Immaterial minds refer to the concept that minds or consciousness are not physical substances but rather non-physical entities. The video suggests that if we are not physical, then we might be immaterial minds, which aligns with the mind-body dualism argument. The idea is used to explore the possibility of life after death, as immaterial minds would not be subject to the same physical decay as bodies.

💡Rene Descartes

Rene Descartes was a 17th-century philosopher who is most famously associated with mind-body dualism, often referred to as 'Cartesian dualism.' The video mentions Descartes as a proponent of the view that the mind and body are separate entities. His work 'Meditations on First Philosophy' is highlighted, which includes arguments for the existence of God and the immortality of the soul, themes that are central to the discussion of dualism.

💡Saul Kripke

Saul Kripke is a contemporary philosopher who is mentioned in the video as presenting a variant of Descartes's argument for mind-body dualism. Kripke's book 'Naming and Necessity,' published in 1980, is noted for its simplified version of Descartes's argument. The video uses Kripke's argument to illustrate the philosophical debate around the nature of identity and existence of the mind separate from the body.

💡Cartesian Coordinates

Cartesian coordinates are a mathematical concept invented by Descartes, which are used to specify points in a plane as ordered pairs of numbers. While this term is not directly related to the main theme of the video, it is mentioned as a historical fact about Descartes, providing context about his contributions to both philosophy and mathematics.

💡Logical Truth

A logical truth is a statement that is true by virtue of its logical form, independent of any external facts. In the video, logical truths are used to contrast with contingent truths. The example given is 'either there were dinosaurs, or there were no dinosaurs,' which is necessarily true. This concept is crucial for understanding the argument that if you are Bert (your body), then it could not have been false, highlighting the necessity of identity.

💡Contingent Truth

Contingent truths are statements that are true but could have been false under different circumstances. The video contrasts these with logical truths, using the example of the speaker being a philosopher, which could have been false if they had chosen a different career. This distinction is important for the argument that one could have existed without Bert (the body), suggesting that 'you' and 'Bert' are not identical.

💡Modus Tollens

Modus tollens is a logical rule of inference that allows for the conclusion 'not P' from the premises 'If P, then Q' and 'not Q.' The video uses this rule to structure the argument against the identity of the mind and the body. By establishing that 'you' could have existed without 'Bert' (not Q), and if 'you are Bert' then it could not have been false that you are Bert (If P, then Q), it logically follows that 'you are not Bert' (not P).

💡Identity

Identity, in this context, refers to the state of being the same entity. The video discusses the concept of identity to argue that 'you' and 'Bert' (your body) are not identical. The argument hinges on the possibility of 'you' existing without 'Bert,' which would mean that 'you' and 'Bert' are not one and the same thing, supporting the dualist view.

💡Immortality

Immortality is the concept of living forever or enduring eternal life. The video connects the idea of mind-body dualism to the possibility of immortality, suggesting that if the mind is an immaterial entity separate from the physical body, it might continue to exist after the body's death. This concept is important for those who are invested in the idea of an afterlife.

Highlights

Introduction to mind-body dualism by Alex Byrne, a philosophy professor at MIT.

Dualism posits that we are not physical or material things, but rather mental or immaterial entities.

The importance of dualism for the concept of immortality and life after death.

Rene Descartes, the 17th-century philosopher, as the most famous proponent of mind-body dualism.

Descartes' work 'Meditations on First Philosophy' and its promise to demonstrate the existence of God and the immortality of the soul.

The argument presented is a variant of Descartes's argument by philosopher Saul Kripke.

The argument aims to show that the self is not identical to the physical body, named 'Bert' in the example.

The distinction between truths that could have been false and those that could not have been false.

Logical truths, such as the law of identity, as an example of truths that could not have been false.

The argument's first premise: If it's true that you are Bert, then it could not have been false that you are Bert.

The possibility of existing without a body (disembodied) or with a different body (Bertha) as a counterargument.

The second premise: It could have been false that you are Bert, based on the possibility of existing without Bert.

The use of 'modus tollens' logical inference to derive the conclusion that you are not Bert.

The conclusion of the argument supports the dualist view that the self is not identical to the physical body.

The practical implications of the argument for beliefs about personal identity and the afterlife.

Transcripts

(intro music)

So my name's Alex Byrne.

I teach philosophy at MIT, and today

I'm going to explain an argument

for so-called mind-body dualism,

the view that we are not physical or material things.

And if we're not physical or material things,

the natural alternative is that we're

mental things of some kind.

Immaterial minds or souls,

as it's sometimes put.

Hence the term "mind-body dualism."

On this view, the universe contains

two quite different sorts of things:

physical bodies like stones

and planets and brains on the one hand,

and non-physical minds on the other.

Well why is this view important?

Well, physical things normally

aren't around forever.

If I smash my watch into tiny pieces

or throw it in a furnace, that's the end

of this beautiful piece of Swiss engineering.

The watch doesn't exist anymore.

Similarly if your body is devoured by worms

or consumed in a crematorium,

that's the end of this beautiful piece

of biological engineering.

Your body doesn't exist anymore.

So, if you're a physical thing,

a complicated bag of cells,

then your eventual bodily destruction

means that there's no hope for immortality.

So, if you're invested in the prospect

of life after death, a lot hangs on

the argument for mind-body dualism.

The seventeenth-century philosopher Rene Descartes

is the most famous proponent

of mind-body dualism, and that's why

the view is sometimes called "Cartesian dualism."

You'll remember Cartesian coordinates

from high school geometry,

and Descartes invented those.

His most famous work is called

"Meditations on First Philosophy,"

which was published in Latin in 1641.

And the sub-title promises that the work

will demonstrate the existence of God

and the immortality of the soul.

We can only do so much in a few minutes,

so we'll have to leave the demonstration

of the existence of God

for another episode of Wi-Phi.

Now the argument I'm going to present

is not quite Descartes's argument

as we find it in the Meditations.

It's basically a variant of Descartes's argument,

given by the contemporary philosopher Saul Kripke

in his classic book "Naming a Necessity,"

which was published in 1980.

And what's more, it's a simplified version

of Kripke's argument.

But even with the simplifications,

I think we can see that it certainly

leads to an argument that deserves

to be taken seriously.

All right, so now to the argument.

Let's give your physical body a name.

Call it "Bert."

Everyone, dualist or not, can agree you and Bert

are intimately connected.

Stamp on Bert's toe, and you feel pain.

If you decide to get some aspirin,

that will result in Bert moving

towards the medicine cabinet.

However, that doesn't mean that you are Bert.

And according to the dualist, you aren't.

There are two things here: you and Bert.

And what the dualist argument tries to establish

is that you are not Bert.

More explicitly, you are not identical to Bert.

You are not one in the same thing as Bert.

Okay, so that's the conclusion.

So now, to prepare for the premises of

the argument, we need a distinction,

between truths that could have been false

and truths that could not have been false.

For example, here's a truth:

I am a philosopher.

That truth could have been false.

I could have been a plumber, say.

Plumbing might have struck me as a more

fulfilling and secure career than philosophy,

and I might have studied

for a plumbing certificate instead

of studying for a PhD in philosophy.

Here's another example:

it's true that there were dinosaurs.

But that could have been false.

Evolution could have failed to produce

any dinosaurs, or life might not have evolved at all.

So some truths, then, could have been false.

But some truths could not have been false.

They had to be true, come what may.

For example, here's a logical truth:

either there were dinosaurs, or there were no dinosaurs.

That's true, but it didn't just happen to be true.

It couldn't have been otherwise.

However the world turned out,

that logical truth would have been true.

Here's another example, which is

the relevant one for our purposes.

Imagine that the President of the United States, say,

is sitting opposite us.

I point to him and say, "He is Barack Obama."

That's true.

But could it have been false?

Well, how could it?

How could that very man fail to be Barack Obama?

We have just one thing here:

that man, also known as "Barack Obama."

When I say "He is Barack Obama,"

I'm picking out the same thing twice over.

It's as if I were to say "He,"

pointing at Obama, "is him," pointing at Obama again.

A thing can't fail to be identical to itself.

So "He," here I point at Obama,

"can't fail to be identical to Obama."

So, when I say "He is Obama," what I say

is not just true, it had to be true.

It's one of those truths like that

logical truth I just mentioned.

It could not have been false.

If you're inclined to doubt this,

you're probably thinking of some different,

but related, truth that could have been false.

For example, it's also true that he,

pointing at Obama, is named "Barack Obama."

But that's a truth that could have been false.

He might have had some, different name say Fred Blogs.

But the truth that he is Barack Obama is not the same

as the truth he's named Barack Obama.

The first truth is not about language,

although of course it is stated in language,

like truths in general.

It's just about the man, Barack Obama.

The second truth is about language,

at least in part.

Specifically, it's about the name "Barack Obama."

And of course these are quite different things.

Barack Obama is the president, but his name

has not been elected to any office.

All right, now we're ready for the argument.

Go back to you and Bert, your body.

Imagine I point to you and say "You are Bert."

Suppose that's true.

Then, since it's just like the Obama example,

it's one of those truths that could not have been false.

In other words, if it's true that you are Bert,

it had to be true that you were Bert.

You are Bert, come what may.

So this gives us the first premise

of our argument for dualism.

If it's true that you are Bert,

then it could not have been false that you are Bert.

But hold on.

Couldn't you have existed without Bert existing?

For example, you can imagine being

disembodied, not having a body at all

or you can imagine that you have

another body, Bertha, not Bert.

Imagining these situations is not at all

like imagining, or trying to imagine, say,

a situation in which there's a round square table.

That situation seems obviously impossible,

not a situation that could have obtained.

There could not have been a round square table.

But there seems nothing at all impossible

about a situation in which you exist without Burt existing,

perhaps because you're disembodied,

perhaps because you have Bertha

and not Bert as your body.

This is not the actual situation,

but it seems like a possible situation.

You could have existed without Bert existing.

But if you could have existed without Bert existing,

then it could have been false that you are Bert.

A situation in which you're around and Bert isn't

is a situation in which you aren't Bert.

So this gives us our second premise,

"it could have been false that you are Bert."

So now notice that the second premise

is the negation of the sentence

after the word "then," in the first premise.

So our two premises have

the following abstract form:

"If P, then Q; and not Q."

And premises of this form logically imply,

by a rule of inference called "modus tollens," "not P."

And our two plausible seeming premises, then, imply

"it's not true that you are Bert."

In other words, you are not Bert,

which is the dualist conclusion.

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