Recap – True or False - PowerPoint Presentation

Recap – True or False Leibniz’s Law states that if two things have all the same properties then they are identical (the same thing). Two pens that are the same colour, shape and have the same ink could be called identical according to Leibniz’s Law. The person who argued for Substance Dualism was David Hume. A substance is something that depends on other things to exist. A property is something that does not depend on other things to exist. Descartes argued for substance dualism because he said he could doubt his body but not his mind, this meant they are two different things. He also used the argument from indivisibility, that states the body can be divided but the mind cannot be therefore they are two different things. Modern neuroscience seems to support the idea that the mind cannot be divided. Science seems to show that there are some physical things that cannot be divided. It is possible that the mind is simply a non-divisible property of the brain, similar to temperature or colour.

Recap – True or False Leibniz’s Law states that if two things have all the same properties then they are identical (the same thing). Two pens that are the same colour, shape and have the same ink could be called identical according to Leibniz’s Law. The person who argued for Substance Dualism was David Hume. A substance is something that depends on other things to exist. A property is something that does not depend on other things to exist. Descartes argued for substance dualism because he said he could doubt his body but not his mind, this meant they are two different things. He also used the argument from indivisibility, that states the body can be divided but the mind cannot be therefore they are two different things. Modern neuroscience seems to support the idea that the mind cannot be divided. Science seems to show that there are some physical things that cannot be divided. It is possible that the mind is simply a non-divisible property of the brain, similar to temperature or colour.

Recap – Divisibility Argument I am indivisible. My body is divisible. Therefore I am not my body. Modern neuroscience seems to show the mind is divisible. Certainly if we remove parts of the brain we seem to remove parts of the mind (e.g. understanding words). Perhaps the mind is divisible but that still doesn’t make it the same as the body. The body is spatially divisible – it can be broken up into pieces in space. The mind is functionally divisible, if it can be divided it is only on the basis of it’s functions, not spatially. There already seems to be more than one p art to the mind – there are unconscious things that our mind just does (keeps us breathing / balanced) without requiring us to think about it. This seems to be obviously different to conscious thought and action.

Recap – Divisibility Argument I am indivisible. My body is divisible. Therefore I am not my body. Whilst my body does seem to be divisible, matter (which is the substance Descartes ultimately is discussing here) is not infinitely divisible, the smallest kinds of substance seem to be in the form of waves, force fields or packets of energy – none of which seem to be able to be broken up.

Recap – Divisibility Argument I am indivisible. My body is divisible. Therefore I am not my body. Some properties of the physical substance (hot/cold, rough/smooth etc.) cannot be divided. Is it possible the mind is simply a property of the physical substance like these and not a separate substance of it’s own?

Conceivability Argument First, I know that everything which I clearly and distinctly understand is capable of being created by God so as to correspond exactly with my understanding of it. Hence the fact that I can clearly and distinctly understand one thing apart from another is enough to make me certain that the two things are distinct , since they are capable of being separated, at least by God. The question of what kind of power is required to bring about such a separation does not affect the judgment that they are distinct. Thus, simply by knowing that I exist and seeing at the same time that absolutely nothing belongs to my nature or essence except that I am a thinking thing, I can infer correctly that my essence consists solely in the fact that I am a thinking thing. It is true that I may have (or, to anticipate, that I certainly have) a body that is very closely joined to me. But, nevertheless, on the one hand I have a clear and distinct idea of myself, in so far as I am simply a thinking, non-extended thing; and on the other hand I have a distinct idea of body, in so far as this is simply an extended, non-thinking thing. And accordingly, it is certain that I am really distinct from my body, and can exist without it. What argument is Descartes making here? Can you split it into premises and conclusion?

Conceivability Argument If I can clearly and distinctly conceive of the essential nature of two things as separate, it must be possible to separate them. I can conceive of the nature of my mind as a thinking, non-extended substance. I can conceive of the nature of my body as an extended, non-thinking substance. Since I can conceive of these things as distinctly separate it must be possible for them to be separate. Meaning they don’t depend on one another, therefore they are two separate substances.

Hume’s View “If I can conceive of something, then it is logically possible.” Which of these things can you conceive of (i.e. truly think about)? A Male Nun Round Pyramids Alcohol-Free Whisky A Flying HorseTrump as PresidentWater being H30Cold SoupWomen BishopsMarried BachelorAn Egg-Laying Mammal If you can think about something (conceive of it) then that thing is logically possible, it could be true, even if it is not true in our world. (Think - Possible worlds)

Conceivability “ Since I can conceive of the mind and body as separate it must be possible for them to be separated in reality. Meaning they are two separate substances .” I can think of this, on it’s own, as a thinking non-extended thing. I can think of this, on it’s own, as an extended non-thinking thing. Since I can think of each thing on it’s own, it must mean it is possible for that thing to exist alone (without the other, even if it doesn’t in our world). Since it is possible for each to exist on it’s own, this means they do not depend on one another. This means they are two separate substances.

Conceivability Argument If I can clearly and distinctly conceive of the essential nature of two things as separate, it must be possible to separate them. I can conceive of the nature of my mind as a thinking, non-extended substance. I can conceive of the nature of my body as an extended, non-thinking substance. Since I can conceive of these things as distinctly separate it must be possible for them to be separate. Meaning they are two separate substances.

Conceivability Argument If I can clearly and distinctly conceive of the essential nature of two things as separate, it must be possible to separate them. I can conceive of the nature of my mind as a thinking, non-extended substance. I can conceive of the nature of my body as an extended, non-thinking substance. Since I can conceive of these things as distinctly separate it must be possible for them to be separate. Meaning they are two separate substances.

Critique – Mind Without Body? What does the mind look like? How might we see reality without a body?

Critique – Mind Without Body? Mind without body is not conceivable Is it truly possible to think about a mind without a body? Every frame of reference we have requires senses that use physical data to tell us about the world. In everyday life we recognise people as being the same as their bodies – our friends and family are flesh and blood bodies, not disembodied souls. Without their bodies we would not recognise them.It seems impossible then to conceive of the mind without the body, and if this is true then it means that a mind without body is logically impossible. Premise 2 is flawed.

Critique – Logically Possible > Reality? Can you conceive of a flying horse? Is it possible for horses to fly under their own power in this reality ? Does this mean it’s logically impossible for horses to fly?What might this mean for the mind?

Critique – Logically Possible > Reality? Logical Possibility does not dictate reality Just because we accept the possibility of something does not mean that it is true in this reality. For example: I can conceive of a flying horse and imagine how one would work, but just because it is possible in one world does not mean it is true in this world. There are natural laws that go against this happening.Logical possibility does not mean physical possibility.Even if we accept that is possible that the mind could exist without the brain it does not mean it is true in our world/reality. We should not be using a priori reasoning to make empirical claims about the world and reality around us.

Checklist Difference between substances and properties. Descartes Substance Dualism Descartes argument from doubt Descartes argument from divisibility Criticisms of the argument from divisibilityDescartes argument from conceivabilityCriticisms of the argument from conceivability

What can you remember? Can you outline the conceivability argument? What issues have we seen so far?

Conceivability Argument If I can clearly and distinctly conceive of the essential nature of two things as separate, it must be possible to separate them. I can conceive of the nature of my mind as a thinking, non-extended substance. I can conceive of the nature of my body as an extended, non-thinking substance. Since I can conceive of these things as distinctly separate it must be possible for them to be separate. Meaning they are two separate substances.

Critique – Mind Without Body? Mind without body is not conceivable Is it truly possible to think about a mind without a body? Every frame of reference we have requires senses that use physical data to tell us about the world. In everyday life we recognise people as being the same as their bodies – our friends and family are flesh and blood bodies, not disembodied souls. Without their bodies we would not recognise them.It seems impossible then to conceive of the mind without the body, and if this is true then it means that a mind without body is logically impossible. Premise 2 is flawed.

Critique – Logically Possible > Reality? Logical Possibility does not dictate reality Just because we accept the possibility of something does not mean that it is true in this reality. For example: I can conceive of a flying horse and imagine how one would work, but just because it is possible in one world does not mean it is true in this world. There are natural laws that go against this happening.Logical possibility does not mean physical possibility.Even if we accept that is possible that the mind could exist without the brain it does not mean it is true in our world/reality. We should not be using a priori reasoning to make empirical claims about the world and reality around us.

Critique – Conceivable > Possible? Descartes invited commentary from the scholars of his day, one Antoine Arnauld raised a criticism that he felt the need to address: The criticism was levelled at Descartes first premise that what is conceivable is always possible. To demonstrate his issue he offered a parallel argument using Pythagoras’ theorem. Someone ignorant of Pythagoras might well suppose that they could conceive of a right-angled triangle that lacked this property, but it wouldn’t follow that is it actually possible for this triangle to exist. Not even God could create it. The fact that Descartes can conceive of the essence of his mind being separate from his body does not show that it is actually possible to separate them. It is possible Descartes is mistaken, is missing some crucial information or has simply misunderstood the essence of his mind.

The Masked Man Fallacy… “Suppose you go to a masquerade ball and you meet a charming man. You don’t know who the masked man is, but someone suggests that it could be your father. But you say “Of course it isn’t, I know who my father is and I don’t know the masked man”, so you can’t conceive of the masked man being your father.” Does this mean your father is not the masked man?

Critique – Masked Man Fallacy? I know who my father is. I do not know who the masked-man is. The masked-man and my father have different properties. The masked-man and my father are therefore two distinct different things.

Critique – Another Way? Lois Lane believes that Superman can fly . Lois Lane does not believe that Clark Kent can fly . Therefore Superman and Clark Kent are not the same person. We cannot automatically assume that subjective knowledge of something (or even a group of things) is enough for making accurate, non-contradictory statements. What we believe is a property of us, not the thing in question therefore we cannot make accurate statements based purely on our subjective knowledge.

Conceivability Argument If I can clearly and distinctly conceive of the essential nature of two things as separate, it must be possible to separate them. I can conceive of the nature of my mind as a thinking, non-extended substance. I can conceive of the nature of my body as an extended, non-thinking substance. Since I can conceive of these things as distinctly separate it must be possible for them to be separate. Meaning they are two separate substances.

The Evolution Problem Descartes made it abundantly clear in his work that humans are the only creatures with minds. Everything else is merely acting on physical causes. This however presents a problem if you believe in evolution… Evolution suggests that the mind evolved in a similar way to organs and nerves in our body – as a survival strategy emerging from genetic variation. Essentially, we evolved minds to help us work out danger. This capacity seems to be present in other animals as well. But if this is correct then it would suggest that our minds evolved over millions of years as a product of an increasingly complex brain (hence why some animals seem to have simpler minds), and not something else entirely separate (as Descartes would have us believe). Evolution does not support the mind being a separate substance.

Finally – Mind = Brain We’ve already seen a video in which changing the brain in some way seems to change the mind. This seems to suggest that the mind categorically depends on the brain in some way, that we cannot conceive of them separately. Descartes would not have been aware of such a link as research into brain function would not be carried out until much later. If we can’t conceive of a separate mind, this argument seems to fail.

Important Note There are a number of other criticisms that are in your handbook that can be applied to dualism as a whole. With this in mind we will be covering them later on in the course after going through the other dualist theory rather than having to recap them after each. These are: Interactionist IssuesEpiphenomenalist IssuesProblem of Other Minds / Solipsism

Opinion Line The mind and the body are two separate substances.

Opinion Line The mind is a non-physical thing.

Opinion Line Our mind is simply a product of evolution.

Substance Dualism Exam Style What are qualia? (3 marks) Briefly outline Descartes’ indivisibility argument (5 marks) Critically assess substance dualism (25 marks) Exam = 3 Hours 2 Topics (Mind and Ethics) 5 Questions on each topic3 Mark, 2x5 Mark, 12 Mark, 25 MarkExaminer will expect definitions, key thinkers and explanations in more detail than you covered in AS.Essays should include your own ideas as well as the ones we’ve studied in lesson.Redundancy can still lose you marks! The time is lengthy to allow you to do philosophy! Enjoy it!