Mind-Body Problem PDF

The Mind-Body Problem Introduction to Philosophy Lecturer: Akiko Frischhut Your friend What would your friend have to keep to remain your friend? 2 Your friend What would your friend have to keep to remain...

The Mind-Body Problem Introduction to Philosophy Lecturer: Akiko Frischhut Your friend What would your friend have to keep to remain your friend? 2 Your friend What would your friend have to keep to remain your friend? Presumably their mind, ability to think and (maybe) communicate. We tend to emphasis the mental aspects of ourselves more than the physical aspects. This is the Cartesian answer to the question – you are your thinking, self-conscious mind. 3 The Mind-Body Problem What is the relationship between mind and body? What is the relationship between mental properties and physical properties? 4 The Mind-Body Problem Rene Descartes (1596-1650): I think, therefore I am. But what am I? A thing that thinks.  The Mind-Body Problem Descartes was a substance dualist. He believed that there were two kinds of substances: matter, of which the essential property is that it is spatially extended; and mind, of which the essential property is that it thinks. 6 The Mind-Body Problem Substance dualism has a famous problem, the interaction problem. If mind and body are distinct substances, how do they interact? First, do we accept that if mind and body are different substances then they cannot interact? Why? 7 The Mind-Body Problem Interaction problem for substance dualism I In so far as the mental is radically different from the physical, they do not have enough in common to interact with each other. If all causation is by impact, how can the immaterial impact on the material? The Mind-Body Problem Interaction problem for substance dualism Conflict between interactionism and basic principles of physical science: Causal Closure: The physical world is causally closed – every physical event is caused by another physical event No Overdetermination: nothing is determined by more than one cause The Mind-Body Problem Interaction problem for substance dualism For X to be a cause of Y, X must contribute something to Y. The only way a mental event could contribute to a physical one would be to contribute some feature not already determined by a physical event. But if Causal Closure is true, there is no feature not already determined by a physical event. Given No Overdetermination, interaction between mental and physical events is not possible. The Mind-Body Problem Gottfried Wilhelm Leibniz (1646-1716) argued that because the mental and the physical cannot interact, either (a) the mind and body do not interact or (b) the mind and the body are not separate substances Leibniz chose (a) the mind and body do not interact. He argued that there is only a “pre-established harmony” (by God) between the mental and the physical. The Mind-Body Problem Baruch Spinoza (1632-1677) chose (b) the mind and the body are not separate substances. This is called the “dual aspect” theory – mind and body are both aspects of the same substance. The Mind-Body Problem 1. Mind and body do interact; physical events do cause mental events and mental events do cause physical events. 2. Mind and body don't interact; mental events and physical events occur simultaneously (Leibniz’ pre-established harmony) 3. There are no mental events (physicalism). 4. There are no physical events (idealism). 5. Mental events and physical events are in fact the same (two aspects of the same thing). (Spinoza) Varieties of Materialism: Behaviourism Behaviourists hold that talk of the mental is really just sophisticated talk of behaviour. The mental is really just a pattern of behaviour. A mental fact is really a disposition to behave a certain way in certain circumstances. Behaviourism Behavioural dispositions are like dispositions of physical objects: for example, what it is for a glass to be fragile is for it to be disposed to break when dropped. Behaviourism To make a statement about the mind is to make a prediction about the subject's behaviour. Example: To say that x is thirsty is to say that x will drink water when it is available. Objections to Behaviourism 1) Tomoko may believe that it's going to rain even if she's not disposed to wear a raincoat and take an umbrella when leaving the house (or to perform any other cluster of rain-avoiding behaviors), if she doesn't mind, or enjoys getting wet. Objections to Behaviourism 2) Subjects can suppress their tendencies to pain behaviour even in the presence of excruciating pain, while skilled actors can produce pain behaviour even if they don't actually feel pain. Objections to Behaviourism 3) For a conditional like ‘if X happens, then S will react with Y’ there must be something happening IN THE BRAIN in virtue of which this happens. So, mental events are not behaviour, they are the physical brain events that make that behaviour happen! Varieties of Materialism: Identity Theory (Physicalism) Mental events are identical to their correlated brain states. Identity Theory (Physicalism) We are familiar with such identities. For example: Water = H2O. Our descriptions of water and H2O will be very different – being wet (!), falling from the sky, being potable, etc. are different from the chemist's description of the water molecule in terms of hydrogen and oxygen atoms. Nevertheless, these two descriptions describe exactly the same thing. Perhaps mental states are like this. Identity Theory (Physicalism) But are they? Could we in principle translate all or our mental talk into talk of brain processes (as we can with “water” and “H2O”)? Instead of ‘I am pain’ we would correctly say ‘my c- fibers are firing’? Would that latter description leave something out? Identity Theory (Physicalism) PROBLEM: Leibniz Law: For any x and y, if x is identical to y, then x and y have all the same properties. If mental states are identical to brain states then they must, by Leibniz Law, share all the same properties. Identity Theory (Physicalism) Do pains and their brain process really have everything in common? Your brain process has a certain location in your brain. Does your pain? What about your desire to have an ice cream or your belief that Akita is a city in Japan. Do those have locations? Problems with the identity theory: 1) not every mental event correlates with a specific physical process Reply: Maybe my mental event depends on my brain state in general. Problems with the identity theory 2)Suppose we discover that in humans pain = C-fibres firing. We then discover some aliens. When we jab them with a pin, they show all the signs of being in pain and yet their brain has no C-fibres. But pain = C-fibres firing! So we cannot say that the aliens feel any pain. -human-centric -undermines much explanatory power we have in understanding other creature’s behaviour. Chalmers argues that we can conceive being outside of a world physically indistinguishable from our world but in which there is no consciousness (a zombie world). From this (so Chalmers argues) it follows that such a world is metaphysically possible. Therefore,..? David Chalmers: No A priori entailment from the physical facts to the mental facts. Physicalism is false.