Philosophy of Mind: Chapters 1-7 PDF

Chapter 1 - Experiences like tasting coffee, having thoughts about a city, and feeling emotions like happiness are examples of mental states, together, such states form the conscious mind. - The fact that experiences, thoughts and emotions exist is beyond any doubt. Doubting this would in itself...

Chapter 1 - Experiences like tasting coffee, having thoughts about a city, and feeling emotions like happiness are examples of mental states, together, such states form the conscious mind. - The fact that experiences, thoughts and emotions exist is beyond any doubt. Doubting this would in itself be a mental state, thereby proving the point that the conscious mind does indeed exist. Preliminary characterisation of the conscious mind - Experiences like that of tasting coffee, of seeing beauty, of watching the waves, all have qualitative aspects. In philosophical jargon, these qualitative aspects of experiences are called qualia (singular quale), or the what-it-is-likeness, a phrase made by Thomas Nagel. He argued that when our senses are stimulated we have all kinds of experiences. - Types of mental states: 1. Phenomenal experiences- described by the what-it-is-likeness. They are characterised by their qualitative feel. The term phenomenal refers to how something feels, how something appears to us, how something is experienced. Thus, phenomenal experiences are characterised by their what-it-is-likeness. Put differently: qualia are the qualitative aspects of phenomenal experiences. 2. Cognitive state- can be characterised by saying that they possess intentionality. Intentionality is the property of being about something also called aboutness. my thought about my friend in the bar and Amsterdam clearly is about my friend and the bar in Amsterdam. The notion of intentionality is somewhat confusing because the term intentionality may also refer to the mental state of wanting to do something on purpose. If I intend to have another cup of coffee, I will order one on purpose, and my intention (mental state) has intentionality (aboutness): it is about the next cup of coffee. In many philosophical texts, the archetype of a mental state with intentionality is the propositional attitude. A proposition is the meaning of a sentence. In addition you may have different stances or attitudes towards a proposition, like knowing, believing, hoping or wanting. It is evident that propositional attitudes have intentionality. 3. Emotion- possesses both what-it-is-likeness and aboutness. If someone says “it feels so good being in love” we automatically assume this phenomenal feeling is directed towards someone (about someone). It would be strange when asked who it is, they say no one, but it feels good. So an emotion like being in love not only has a phenomenal feel, it is about someone as well. - If you close your eyes and then gently push your eyelids, the pressure on your eyeballs results in “seeing stars”. However, you also know that they have nothing to do with reals stars. In other words: you have an experience that possesses what-it-is-likeness but not aboutness. Similarly, there might be mental states that do have intentionality without having a single quale. It is conceivable that in the fitter intelligent robots may be able to have cognitive states while lacking the ability to experience anything at all. Thus, we can distinguish those mental states that are characterised by qualia and those that are characterised by intentionality. - To summarise, we can initially distinguish three mental states, characterised by two different properties. The conscious and the unconscious mind - The states of the unconscious mind can become conscious given the right circumstances. “The notion of an unconscious mental state implies accessibility to consciousness”. A good example is personal memory. - Most of our memories are unconscious initially, but they can become conscious. For instance, think of your first crush, before reading that you probably weren’t thinking of your first crush, but now this memory has become a conscious thought, or a set of conscious thoughts. - There is a lot going on inside of us that we will never be conscious of. Many states, like the brain state that regulates our heartbeat, neither belong to the conscious not unconscious mind. Such states of course are not conscious, in a sense, they are unconscious. However, these states are not mental states because they lack the ability to become conscious states. The mind-body problems - The central mind-body problem is how the conscious mind fits into the physical world. Since we have three mental types, we seem to have three mind-body problems. Problem 1: How do phenomenal experiences fit into the physical world? Problem 2: How do cognitive states fit into the physical world? Problem 3: How do emotions fit into the physical world? - Even though we have three types of mental states, they are defined by just two properties: qualia and intentionality. So actually we have only two problems. Problem I: How do qualia fit into the physical world? Problem II: How does intentionality fit into the physical world? - The idea behind this reduction to two problems is that once we know how qualia and intentionality fit into the world, we will not only know how respectively phenomenal and cognitive states fir into the world, but also what place the combination of the two- the emotions- is. Consciousness and cognition - The term cognition is used to refer to the part of the mental state that have aboutness. Consciousness is often used to refer to the phenomenal states of the mind, mainly because cognitive states are mental states that can also become conscious states. Thus, many cognitive states are mental states while not being part of the conscious mind- but they do have the ability to become part of it - A phenomenal states id by definition conscious, so it makes sense to use the term “consciousness” as a default for phenomenal states. Clearly this does not mean that cognitive states are never conscious states. Taking science seriously - The debate about the conscious mind is traditionally seen as a philosophical debate, but often it is also seen as a metaphysical debate. Metaphysics is the discipline in philosophy  that goes beyond physics. Thus, if the science of physics tells us which physical things our universe holds, metaphysics tells us that is beyond (palpable) nature. Metaphysics tells us how it is possible that a world exists in the first place - If the debate of the conscious mind were indeed a metaphysical debate, the mind and its relation to the physical world would belong in a domain of the world that is defined as field science has no say in. - Many philosophers believe that this kind of philosophy is detached from the real world thus giving philosophy a bad name. Metaphysics is the type of philosophy that does not take into account what science has discovered about the world; it chooses fantasy and wild speculation over our best way to gain knowledge about and insight into our world. - The problem about the conscious mind and its place in nature must be answered by science, because science is our best way of finding out what the world is and how it works. - Philosophy is necessary because it is the discipline that asks questions about concepts like, what do you mean by the concept of conscious mind or cognition. Furthermore, it fine brings together data from different scientific fields and comes up with testable hypotheses that scientists themselves might not propose, mainly because they often are focused on tackling a very specific topic. - Moreover, philosophers are trained to discover false reasoning. As the famous French philosopher René Descartes noticed: we are indeed able to reason properly, but we are also prone to making errors. Chapter 2 Montaigne - Many people hold religious or spiritual beliefs, usually that the soul survives our bodily death. In this view, the conscious mind is the same as the soul. In other words, many people accept the idea that the mind can exist and function separately from the physical world. - Undoubtedly, the most influential proponent of the separability thesis in philosophy was the French philosopher René Descartes, who initially responded to skeptics like Montaigne - Skeptics are the philosophers who argue that we can never be certain about anything, and that we will always have to postpone our judgements. In his search for certainty, Montaigne came to see that there was nothing he could be sure of: any claim was open for doubt. - If you say that there is nothing you do know for certain, you are already making a knowledge claim: you say you know for certain that you do not know anything for certain. Since even this minimal claim was too strong for Montaigne, he did not claim anything, but merely posed the question “What do I know”. - Separability thesis- mind can function separated from the physical body - Inseparability thesis- mind cannot function separated from physical body Descartes - He argued that he should not trust anyone or anything that has deceived him in the past. This led him to distrust other humans since they had not always told the truth, they could no longer be trusted as a source of true knowledge, same goes for senses. - If our senses sometimes deceive us, like they can in the case of visual illusions, how can we be sure they do not deceive us all the time? - He said that he could conceive a malicious almighty demon: a demon so powerful that it was able to deceive Descartes into thinking that he had a body or that there was a physical world. Descartes was looking for clarity, but he now doubts whether there actually is a physical world and whether he has a body. He even thinks that he might be wrong about the simplest things in maths. Descartes foundation - He argues that no matter how powerful the evil demon is, he cannot have him doubt his own existence. And doubting is a way of thinking: if you doubt, you think, and if you think, you have to exist. The only thing he can say for now is that he is a thinking thing. - Cogito ergo sum- I think therefore I am - He started his search using the method of doubt, to see whether there was anything he could not doubt. Now he has another method that can help him find truths: those claims that he perceives clearly and distinctly have to be true. - When he examines the contents of his mind, he sees that he has ideas. One of those ideas is that of God- according to Descartes, an idea of the most perfect being. Since he could not himself be the origin of this idea- for he is imperfect- it had to come from a being that is indeed the most perfect being. This is one of his proofs for the existence of God. - The same applies for the God’s goodness. It is evident that even though God would be perfectly able to deceive him, God will not deceive Descartes for in deception there is imperfection. And since God does not deceive, the ideas Descartes had about his body and the rest of the physical world must actually originate from the corporeal things themselves, and therefore, they must exits. - This means that Descartes is now certain that he is both a mind and a body. His body is a physical thing that exists in a world among other physical things. Substance dualism - He is then both a thinking thing and a physical thing. According to Descartes, these two things are substances. A substance is that which can exist on its own. 1. The essential property of the thinking substance or res cogitans, is merely that it thinks. 2. The essential property of the physical substance or res extensa, is that it is extended, which means that it is three-dimensional: it has a place in space. There can be only one physical object at a certain place in space at a particular time - Physical bodies are moved by other physical bodies bumping into them, pushing them. And it is only because physical bodies are extended that they are able to bump into others and set them in motion - He also makes clear that the thinking substance is not extended. In other words, the thinking substance does not have a place in space. Since thinking things and physical things are independent substances according to Descartes, they do not need each other to  exist: a body can exist without a mind (rock), and a mind can exist without a body (ghost). Meaning he was a defender of the separability thesis. - He argued that human beings consist of these two substances. Animals, according to him, are mere machines: they are only physical things without a mind. Likewise, the human body is a machine- but a machine that is closely related to the human mind. Descartes says that one might think that the mind is to the body what a sailor is to a ship, adding that is not the proper analogy. He says that since a sailor does not feel anything when the ship is damaged while we do feel pain when our bodies are damaged, we (our minds) are much more closely related with our bodies than a sailor is with his ship. This is why we usually in our everyday conception of ourselves, think of the mind and body as a unity. Princess Elizabeth - Already in her first letter formulated the problem that is now known as the Interaction problem: how can the material body and the immaterial mind interact with each other? - She posed Descartes the following question: How can the soul of a man determine the spirits of his body so as to produce voluntary actions (given the soul is only a thinking substance)? - Contrary to what the word “spirits” is nowadays, the bodily or animal spirits are material. This theory of animal spirits traces back to the Greek physician Galen. According to him, our bodies contain nerves and blood vessels in which small material particles move. The smallest of these particles are the animal spirits. It is by virtue of the movement of these particles that our bodies can move. - According to Descartes, it is in the pineal gland that the soul and the body can influence each other: the soul has the power to move the animal spirits in the pineal gland, and these animal spirits in turn transfer the movement to the rest of the body. Of course this identification of the alleged location of the interaction of mind and body does not explain how the interaction between them occurs. - Any physical body can only move because another physical body bumps into it. This goes for all movement in the entire physical universe. So, if the soul is not extended, how can it interact with the extended world? Elizabeth pointed out this serious problem with Descartes’ substance dualism. - He explains that we might wrongfully think that the way in which a soul moves a body is the same way in which a body moves another body. But since a soul has no extension, it cannot bump into a body. He says that we can conceive how heaviness moves a body towards the centre of the earth. The heaviness does this without bumping into the body. So, here we have a way in which a body is moved without another body bumping into it. The suggestion is that a soul can move a body in a similar way- a way that does not require a collision with the body. - This analogy has flaws, there is a big difference between a soul, which is a substance, and heaviness, which is a property. She was not satisfied and asked for a proper explanation. He replied that we have contradictory beliefs about our souls and bodies. On the one hand, the soul is distinct from the body, on the other hand, we have the belief that body and soul form a unity. He writes: It does not seem to me that the human mind is capable of forming a very distinct conception of both the distinction between the soul and the  body and their union; for to do this it is necessary to conceive them as a single thing and at the same time to conceive them as two things. - So in the end Descartes seems to agree that it is incomprehensible how the mind and body are able to interact with each other. Occasionalism and parallelism - Several followers of Descartes invoked God to solve the interaction problem in one way or another. Descartes strongly suggests in his Mediations that God is in some way responsible for the interaction of mind and body. According to him, God could have constituted man in such a way that when humans step into a nail, they might experience something entirely different than pain. How God is responsible for the interaction is not explained, and can therefore be interpreted in different ways. - According to occasionalists, like Malebranche, the only cause of any event in the world is God. There is only one true cause because there is only on true God; the nature or power of each thing is but the will of God; all natural causes are not at all true causes but occasional causes. An occasional cause is an event that is an occasion for God to cause an event. According to them, causal interaction between soul and body is impossible. It merely seems that there is interaction, genuine body-to-body causation is impossible. The occasionalists’ claim is that God is the cause between two events- mental or physical. God sees, for instance, the mental event of someone who wants to lie his arm, and then causes the changes in the body that correspond to this mental events, so that the person indeed raises their arm. - It was Descartes’ Flemish follower Geulinex who formulated the idea of pre-established harmony between the mental and physical world. Later Leibniz developed the same view, and coined the term harmonia prestabilita for it. - If two clocks run exactly in sync, one chimes when the other does. This happens, of course, without the clocks having a causal relationship. They were made and adjusted alike, so that they would be parallel to each other. The same applies for the mental and physical world: if we want to speak and the tongue moves, then the will accompanies the motion of the tongue without them having a causal relationship. The will and the movement both depend on the same supreme designer who has made them in such a way that they run parallel to each other. - A big problem for both occasionalism and parallelism is that neither is insightful. In both cases God is called to the rescue. However, how God can be the true cause in occasionalism, or how he got both the mental and physical world to run in sync remains a mystery. Chapter 3 Monism - We saw that the problem dualist had was the inability to explain how the two substances interact (mind and body). The obvious solution to this interaction problem is to deny this intuitively plausible idea of substance dualism and defend a substance monism- the view  that there is only one substance, not two. In this view the interaction problem disappears. There are however, different versions of monism. 1. In modern philosophy of mind, the type of monism that is usually accepted is materialism or physicalism. This position claims that everything in the world is physical, everything is material or made out of matter, this also applies to the conscious mind. 2. The second type relates to the other substance: res cogitans or thinking substance. This position that everything in the world is mental is called idealism. The Anglican bishop George Berkeley championed this view. Locke - Berkley responded to a problem that followed from the empiricist views of John Locke. Empiricists claim that we can only gain knowledge about the world via sensory experience. - According to Locke, sunflowers are not really yellow- we merely perceive them that way. This clam seems strange to most people, because we are naïve realists in regard to colour (a view that we develop in early childhood). Most of us naturally think that colours are real. Locke claimed that the same applies to other properties like tastes, smells, and the feeling of warmth: they do not exist without perceivers. - Suppose you forget your mittens and it’s cold outside, one of your hands is in your pocket and the other one is carrying a bag. After getting home you open the tap and wash your hands. The water feels both cold and warm, when the hand that you used to carry something touches water it feels warm, but when the hand that was in the pocket touches it, it’s cold. This leads us to conclude that the warm and cold are not properties of the water itself, but these are properties that we ascribe to water. These properties depend on us. - Locke made the distinction between: 1. Primary properties/qualities- the properties that things really have 2. Secondary properties/qualities- the properties that things do not really have but are ascribed to them when we perceive them - An example of primary property is temperature. Water has a temperature that does not depend on our perception. This is the primary property. Let’s say that the temperature of some water is 18 degrees. This might be experienced as warm or cold. Even though the water is not warm or cold in itself, we still say that it is. We ascribe these properties to water, secondary properties. The same temperature (18) can be cold to me but warm to someone else. - The idea is that the way we perceive primary properties (like temperature) generates in us an experience (like that of warmth), which we then ascribe to the object with the primary properties. Thus the existence of secondary property depends on its perceiver. If there are no perceivers of temperature, the water will still be 18 degrees, but it will no longer be warm or cold. It is only warm or cold relative to an observer. - We can make similar arguments for taste and colour although it is a little harder to do so: you would need to show that you can generate different experiences with the same colour or taste.  Substance - Locke was an empiricist, which means hat he adhered to the idea that we can only get knowledge from our own experience- either via the senses or via introspection/reflection. This idea leads to a problem with respect to primary qualities. - A quality is a property, and a property is always a property of something. But we only perceive the properties, not the thing that has all those properties. For example, a glass of whisky, the colour, smell, and the taste are secondary qualities, but the volume and the shape of the glass are primary qualities. We can imagine that the glass is crystal clear or that it is opaque, it is 5cm high: we can change all the properties of the glass. Now, do not try to change the properties, but try to imagine they are not there in order to get at the thing that lies underneath- that thing has all these properties. The problem now is that with all the properties gone there is nothing left to see. However, Locke maintained that there was a substance underlying the primary properties. But as an empiricist how could he know? This passage is discussing a philosophical idea about how we perceive things. It suggests that everything we experience comes from the properties of an object—things like colour, smell, taste, shape, and size. But we never actually perceive the thing itself—only its properties. Now, if you try to imagine removing all the properties—no colour, no taste, no smell, no shape—what's left? Nothing that you can actually perceive. This raises a problem: if we only ever experience properties, how can we be sure that there’s a “substance” underneath them? - Let us accept that we have good reasons to believe that colours, warmth, tastes, smells, etc. are secondary properties. Are the primary properties as classified by Locke not also secondary properties? The view that they are is called Idealism. Berkeley - He belongs to the three most influential British empiricists. The other two are Hume and Locke. - He says that it is evident that we get our objects of knowledge, our ideas, either via the senses or via perceptions of the workings of our mental lives. Arguing that esse est percipi: to be is to be perceived. Unthinking things, he writes, do not have any existence outside of our minds that perceive them. If primary properties exist, there must be something that has those properties, as well. This is the substance. According to Berkeley, physical objects do not have primary properties and there is no physical substance. - He knew that his readers would not accept this idea easily, and therefore wrote a dialogue between Hyla and Philonous, in which Philonous defends Berkeley’s ideas and Hylas utters his amazement about them. Hylas translates as the matter man and Philonous as the lover of the mind. In the dialogue that follows, Hylas is slowly convinced by Philonous that there is indeed no such substance - Berkeley uses arguments similar to Locke: properties like warmth and cold only exist when we perceive certain objects. For a mite, an object that is small to us- a coin- is huge, but one object cannot be huge and small at the same time. Dimensions and shape are dependent upon the perceiver. This means that Locke was wrong: dimensions and shape are not primary qualities. Hylas is convinced, there is no material world that exists independently of us, or independently of other perceivers. - The conclusion is that a thing’s existence is dependent on it being perceived. Berkeley argues that nothing cannot be perceived. Consequently, that which is perceived has to be real. So if we perceive an object it is real, but then that object is nothing but a bundle of impressions or ideas perceived by various senses. Thus ideas are central to Berkeley’s philosophy- idealism. Because it denies the existence of material substance it is also called immaterialism. - His denial of existence of material substance is often confused with the denial of matter. Berkeley's idea is that things only exist because we perceive them. He does not deny that we see, touch, and experience things (matter), what he denies is that there is some hidden, physical "substance" behind those experiences. - Berkeley’s idealism has an additional problem. If material things depend on being perceived for their existence, what happens to the beer in my fridge when I close the door? No on is looking at it when the door is closed. Berkeley says since it did not cease to exist, it must have been perceived. And since it was not perceived by your mind, there must be a spirit in whose mind all these sensible things exist. This spirit is God. Thus, the permanence of material objects is used to prove the existence of God. Chapter 4 Behaviourism - Behavioursits argue that in order for psychology to be a proper science, it should not accept unobservable mental entities as research objects and therefore should also shun any talk about such subjective mental properties. This had huge implications for the mind-body debate, for it was no longer allowed to talk about the mind in terms of what one experiences. They did not have to stop speaking about the mind, but it did not refer to some spirit anymore, like in the Cartesian view of consciousness. In that sense, the mind did not exist. - The main idea was that psychology was all about describing, predicting, and controlling behaviour. The founder of behaviourism, John Watson, said that in a complete psychological experiment, the stimuli can be worked out given the response and vice versa. For this, no Cartesian mind is needed. - All behaviour, according to Beh., is in essence reflex-like in nature. The model was that there was input (you step on a nail) that goes into a black box, in which we have no idea what is happening and then there is output (you lift your foot and scream). Based on circumstances and input, it should be possible to predict human and animal behaviour. Psychological behaviourism - The motivation for psychologists to accept behaviourism was methodological: science should use an objective method so that all observations could be verified independently. Psychologists like Wundt and Titchener trained subjects to verbally report everything that went through their minds when they were presented a stimulus. - Watson questioned the scientific value of introspectionism, precisely because the observations could only be made by the subject, meaning they were not verifiable.  Another problem with introspection was that it is impossible to study the mental life of animals, they evidently are not able to report verbally in their inner mental life. - The only way for psychology to become a proper science, then, was to turn to that what is publicly available, and therefore objective: behaviour. One of the main proponents, Skinner, even phrased it like this: “Human thought is human behaviour.” - They study the connections between stimulus (input) and behaviour or response (output). In this manner psychologists tried to describe emotions. If you can describe the relation between stimulus and response, you might also be able to control the behaviour of humans and animals by conditioning them. - The most famous example of an experiment in which human emotions were understood in terms of stimulus-response reactions using conditioning was of Little Albert. They presented little Albert with a white rat, to which he initially displayed no fear response. Then, they proceeded to strike a metal bar behind the boy’s head. It made a loud noise and the boy jumped violently. The bar was struck only twice when the boy was presented with the rat, but the following week the boy already showed a fear response to the rat. The experiment was repeated several times, and every time the boy was presented with the rat, without the noise, he started to cry. A couple days later, little Albert was presented with a white rabbit to see if there would be transfer from the rat. Indeed there was, according to Watson and Rayner, the boy started to cry immediately. Philosophical behaviourism - Also called analytical or linguistic behaviourism. We concluded that dualism and idealism do not take science seriously. Descartes thought that animals were just mindless machines, bit how can we establish whether animals or humans have minds? We use behaviour. We cannot directly observe the mind of someone else. So, Ryle argued that is it better to study the mind and no longer think about an immaterial mind. He argued that the mind is nothing more than a set of dispositions to behave, and that if you think that it is more, then you are making a category mistake. - A category mistake happens when someone treats something as belonging to a category it does not belong to. In other words, it's like misunderstanding the nature of a concept by placing it in the wrong logical category. Ryle argues that Descartes made a category mistake by treating mind and body as a separate thing, mind is actually a way of describing behaviour and functions. - Our understanding of the mind is like that of a ghost in a machine (the body). The phrase "a ghost in the machine" was used by Gilbert Ryle to criticise Descartes' dualist view of the mind and body. It means that people mistakenly think of the mind as a separate, invisible entity (a "ghost") controlling the body(the “machine”). - A disposition is a behavioural pattern that one displays under certain circumstances. A classical example of dispositional property is being soluble. If immersed in water, sugar cube will dissolve. In other words, a sugar cube is disposed to dissolve when placed in water, we do not need to refer to some “hidden spirit of solubility”. The same would apply to humans, we have all kinds of behaviour that we display given certain circumstances, and we don’t need any hidden spirit or ghost in the machine to explain this behaviour. - If you think that category ‘mind’ is something over and above the category that all our dispositions to behave belong to, you are making a category mistake. By thinking that two categories are involved, instead of just one, you might generate the problem of how the two different categories are related. - The solution to the mind-body problem is to disqualify the problem as a pseudo-problem because it contains a category mistake. All we need to do in order to understand the mind is to understand our behavioural dispositions, this does not mean that the mind does not exist, it means that the mind just is that set of behavioural dispositions. Logical positivists - Ryle’s ideas are similar to those of logical positivists. They wanted to get rid of pseudo- science and meaningless statements in philosophy and science. They were empiricists and argued that for a sentence to be meaningful or scientific, it had to be related to observations. - According to philosophical behaviourists, all sentences pertaining to psychology deal with the physical behaviour of humans and other animals. No sentence of psychology should therefore contain any reference to any subjective inner state. The claim of behaviourism is therefore that any sentence containing such a reference to a subjective mental term can be paraphrased without loss of meaning. With the result being a very long sentence containing reference only to publicly observable behavioural dispositions. Ann wants to go on holiday -> If we offered Ann a trip, she would say yes Behaviourist dilemma - If behaviourists accepted that there indeed is a mind apart from behaviour, it would mean that they do not study the mind by studying behaviour and thus not rightfully claim to be psychologists. - The dilemma was either to deny the obvious truth, that there was actually more to the mind than behaviour, or to acknowledge it and thereby undermine behaviourism Loss of meaning - There were two reasons why philosophical behaviourism failed, they boil down to the same thing. It is impossible to paraphrase sentences containing a mental term in new sentences containing only behavioural dispositions without loss of meaning. 1. It is impossible to list all the possible dispositions. What are all the possible behaviours that someone might display. Many of these dispositions were left out of the paraphraseBut if we leave this out of the paraphrase, it will have lost meaning compared to the original sentence. The same goes for another aspect that is contained in the meaning of pain. Maybe the most important aspect of pain is the subjective, qualitative feeling, which is left out of the new description. 2. Even though behaviourism takes science seriously, it does not take the mind seriously. Chapter 5 - So far we have seen that dualists and idealists are realists about the mind, but we also saw that they depend on and evoke the powers of God when faced with having to provide answers to the hard questions, which is about as unscientific as it gets. Behaviourists on the other hand, are very scientific in their approach, yet they end up with a theory that either denies the existence of the mind or does not address it at all. - Identity theory is a kind of materialism, it being the position that the world is material or physical, and that all things that exist are thus in some way physical. Materialism and physicalism denote the same. Arguably all material things are physical, but not all things that are physical are material. - In some sense behaviourism is a version of materialism, it clearly is a position that argues against dualism and therefore accepts only material entities. However, we have seen behaviourists not take the mind seriously. The term materialism is usually reserved for realist theories regarding the conscious mind that accept that everything in the universe is material or physical. - In terms of substances, materialists will argue that if there is a substance at all there is only the physical substance. This does not mean that there is no mind: the mind is dependent on the physical. Materialism as a theory about the mind, takes both the conscious mind and science seriously, and comes in a multitude of varieties. Supervenience - Supervenience in general means that one set of properties determines another set of properties. For instance, take the shape and height of a LEGO fire truck. If you have a big box of LEGOs, you only need to follow the building plan’s instructions to assemble a fire truck. This truck will have a certain shape and height. Now if you use the same plan to assemble a second fire truck, you will end up with an object that has exactly the same shape and height as the first truck. The LEGO blocks and their relations- the first set of properties- determine the shape and height of the fire truck- the second set of properties. In other words, the shape and height are supervenient on the blocks and the relations between them. - Mind-body supervenience is the claim that mental properties are supervenient on the physical properties and the relations between them. Any two things that are exactly alike in their physical properties must therefore have exactly the same mental properties. As Kim puts it, physical indiscernibility entails psychological indiscernibility. - If a materialist is a realist about the conscious mind, he accepts mind-body supervenience. The central thesis of the identity theory is: all mental states are identical to certain brain states. In some views, a mental state is thought to involve more than just a brain state. For instance, part of the nerves in the spinal column can also be considered to be part of the mental state.  3 meanings of the term identity 1. One of the notions is that of personal identity. In the mind-body debate, identity is not used to refer to personal identity, even though minds always belong to persons 2. Qualitative identity is the kind of identity between two things that are unlike but at the same time similar in certain aspects. 3. The notion of identity we are concerned with in the mind-body debate is that of quantitative or numerical identity. In a game of 8ball, you cannot pocket the black ball without pocketing the eight-ball, for the simple reason that the only black ball is the eight ball. They are one and the same ball. The eight ball is the black ball and the black ball is the eight ball. This property of identity is called symmetry. If A is, then B is A. The identity theory is concerned with quantitative identity, for it is a theory about the relationship between mind and brain. Leibniz’ law - If “two” things really cannot be discerned from one another, then they must be one and the same thing. This is known as Leibniz’ law, this principle tells us that if object A is discernible from object B, then there has to be a property P that A has and B lacks or that B has and A lacks. - A and B are identical if (and only if) all properties of A are all properties of B, and all properties of B are properties of A. Continent and necessary truths - Empirically discovered truths about identities were considered to be contingent and not necessary truths. If a statement is necessarily true, then denying it will result in a contradiction. If something is contingently the, one could deny it without the denial resulting in a contradiction. - Something that is contingently true could have been otherwise - Something that is necessarily true could not have been otherwise Identity theory (MBIT) - Every mental state is identical with a brain state, but not every brain state is identical with a mental state. Particular brain states, like the one that regulates your heartbeat, are not mental states. Thus, all mental states are brain states are brain states, but not all brain states are mental states. - Only a subset of all brain states is identical to the set of mental states. - Another term for identity theory is reductive materialism. The notion of reduction comes from the layered model we tend to use in thinking about the world. We think of the lowest level or layer of reality as consisting of elementary particles. Then, at a higher level we have atoms, and at an even higher level we encounter molecules. Other levels would include cells, groups of cells, organisms with a CNS… - The idea is that at some levels, new properties come into existence that did not previously exist at a lower level. Liquidity or wetness is something that doesn’t exist at the level of individual water molecules. If a property only seems to be a property of a higher level, while in reality it is not, it can be ontologically reduced to the previous level. In our case,  we might at first think that groups of neurons cannot be conscious and thus, consciousness must be a higher-level property. - If we are able to reduce a mental state to a brain state, this does not mean that we have eliminated the mental state, it still exist. If a mental state is a brain state and the brain state exists, then the mental state also exists, for they are one and the same. Eliminativism - The view that (some) mental states do not exist is called eliminativism. Imagine we say that tasting macaroon pudding is just a result of certain brain activity—meaning we can fully explain it in terms of neurons and chemical reactions. This would mean that the experience exists because it has a clear connection to the physical brain. Now, take free will—if we cannot find a way to explain it as a brain process, some eliminativists might argue that it does not exist at all. Instead of saying, "We just haven't found the brain process yet," they might conclude, "Since we cannot reduce it to a physical brain state, it is an illusion and should be eliminated as a concept.” - So contrary to common intuition that a successful reduction of mental state to a brain state ensures its existence, it is precisely the failure to do so that implies it should be eliminated. Reduction (not eliminated, just explained differently): people once thought lighting was caused by anger gods. Later we discovered it is actually just a huge electrical discharge. We didn’t eliminate the idea of lightning, we just explained it in terms of electricity. Elimination (concept disappears): people used to believe witches caused disease and bad luck. Over time, we realised that illnesses have medical causes, and bad luck is just coincidence. The idea of witches as real supernatural beings was eliminated because there was no evidence for them. Type physicalism - Most common form is type identity theory or type physicalism. This theory states that every individual case of a certain category. Every instance (token) of a certain mental state (type) is always the same kind of brain state. For example, every time someone feels pain, the same specific brain state is happening. It is like saying every time a fire alarm rings, there will be fire (same cause, same effect). - A weaker version is the token identity theory. This says that every mental state has a corresponding brain state, but the don’t have to be the same across all people. For example, when you feel pain, your brain might activate brain state X, but when someone  else feels pain, their brain might activate brain state Y instead. It is like saying different types of alarms can all signal fire (same meaning, but different physical forms. - The key difference: - Type Identity= every ‘pain’ feeling= always the same brain state - Token Identity= each ‘pain’ feeling= some brain state, bot not necessarily always the same one. Arguments in favour of MBIT - There have been many correlations found between types of mental states and types of brain states. 1. The simple explanation: how can we explain the darting correlation between V4 and the experience of colour? In the same way we explain the correlation between the appearance of Superman and the appearance of the Clark Kent: they must be the same person. 2. Ockham’s razor: parsimony states that entities must not be multiplied without necessity. The idea is that, when confronted with two different, but equally good, explanations for a phenomenon or event, we should choose the ontologically more parsimonious one. For example, someone survives a car crash. What is the explanation for this person surviving? The first would be that the car provided a good airbag. The second one is that the car had a good airbag but also that the driver had a guardian angel. Ockham’s razor says that without necessity we should not postulate more entities in our explanation than we need. Everything is explained by the airbag, so we of not need magically assisting guardian angels. Thus, we take Ockham’s razor and cut the guardian angel our of the theory, ending up with the ontologically more parsimonious explanation. It is more parsimonious to accept that metal states are just certain brain states. 3. Causal role analysis: consider the case of genes. We start by asking what relevant mental state does. For example, pain is the result of tissue damage and causes organisms to focus on that damage while also causing them to be stressed. The second question, is the empirical question of what it is that fills this causal role. We have discovered that DNA plays that role. Arguments against MBIT - If a mental state and a brain state are identical, then all properties of the mental state are properties of the brain state, and all properties of the brain state are properties of the mental state. - An identity theorist will claim that we have good reasons to believe that pain is identical to activity in SCIC (part involved in processing pain signals). How can we argue against this? Well we have to find differentiating property. A differentiating property is a property that mental states have but brain states don’t, or vice versa. In other words: if you want to argue against identity theory, you have to show that Leibniz’ law is violated. 1. Can epistemic properties (properties that concern what we know about something and how we come to know it) be differentiating properties? Do you know what it is like to be in pain? Yes, of course: you have direct access to this experience. When you are in pain, you have immediate and direct knowledge that you are in pain. This cannot be said about activity in SCIC. Because we know pain in a different way than we know activity  in SCIC, you might think that this is a differentiating property: mental states cannot be identical to brain states. Water and H2O also have different epistemic properties. So, epistemic properties cannot be differentiating properties. 2. Spatial properties: mental states do not have a location, while brain states do. While some theories accept the latter, MBIT denies it. So we cannot use this argument because the reason against it is just an affirmation of an alternative theory. 3. Semantic properties: properties related to intentionality, meaning or content of a state. Mental states have meaning, but brain states don’t. However, the identity theory says, contrary these seemingly obvious truisms, that these claims are false. In fact, all mental states are three-dimensional and some physical states do not have semantic content. - MBIT takes science and mind seriously. This is a theory that we can accept as scientists who want a scientific theory about the mind. Even when many arguments against MBIT can be rejected, the view has one big problem. The mind seems to be multiple realisable. This creates a big problem for MBIT because it suggests mental states are not tied to just one specific brain process. Chapter 6 - We ended our evaluation of the identity theory with the conclusion that it is the first theory to actually take both science and the mind seriously. However, there is an argument that some regard as fatal for identity theory. This is the argument of multiple realizability- the idea that mental states can be constructed in different ways and made of different stuff. - There is an alternative theory about conscious mind that also takes the mind and science seriously, but which accepts the multiple realizability of mental states. This alternative theory is called functionalism. If functionalism is correct, then machines have minds as well. In order to find out whether we should regard conscious machines as a real possibility, we should first see where the identity theory runs into trouble. Multiple realizability - Humans feel pain, and when they do, their neocortex is active. Fish do not have a neocortex, which leads some scientists to argue that they cannot feel pain. However, fish show pain-like behaviour, suggesting that pain might be realised in a different way in their brains. This means that pain is not tied to one specific brain structure, meaning its multiply realizable. - Mental states (like pain) are multiply realizable, they can exist in different creatures, even if their brains are structure differently. Just like different kinds of clocks tell time in different ways, different types of brains can experience pain in different ways. - Can we reduce pain to a (human) brain state? If fish have different brains and can be in pain, then we can no longer say that pain=human brain state x. For then we would also have to claim that pain=fish brain state y and thus that fish brain state y= pain. Transivity then forces us to conclude that fish brain state y= human brain state x. Since this is  obviously false, the only conclusion is that the identity theory has to be false, we cannot reduce mental states (like pain) to brain states. Machine functionalism - Functionalists claim that mental states are consisted by their causal relationships to sensory input, other mental states, and behavioural output. A mental state is a functional state in the sense that it does something, that it has causal impact on the behaviour of the organism and on other mental states of the organism - Alan Turing argues that machines (like human minds) can think. He develops the notion of computation based on that idea. Computation is using rules to manipulate symbols. He described a machine that could , in principle, perform any computation. - The Turing machine has the following parts: 1. A tape divided into separate compartments that can move from left to right and from right to left, it functions as the memory of the machine. Each compartment on the tape can have just one symbol of the alphabet. 2. A machine head that can read or write the symbols, or overwrite it with another symbol. 3. A set of internal states (configurations) 4. A alphabet b1- bm. - What the machine does depends on its internal state, input, and the machine table- a set of rules that determine what will happen if the machine is in a certain state and reads a certain symbol. - The machine can compute 2+2 (11+11) by following a step-by-step process. Some philosophers believe that thinking works the same way, our brains follow computational rules. The same computation (or thought process) could happen in different physical systems (brains, computers, or even Swiss cheese). This supports functionalism, what matters is how something functions, not what it’s made of. - The mind is multiply realizable, it can exist as a physical computer or as a brain. Thinking is computing. - Fodor was one of the first to defend functionalism. He combined an old with a new idea. The old idea was that mental states have intentionality. The new idea Fodor used was that mental states are computational. He combines computationalism (new idea) with and old idea intentionality. Some mental states are about something. These mental states represent that which they are about. - Folk psychology is the theory that we use to predict and explain the behaviour of others. FP works because we successfully predict the behaviour of others by attributing mental states. Functionalism - Functionalism considers the mind as a whole. Mental states as states that play a causal role in relation to: - Input - Output - Other mental states - To understand the states, we need to look at the relations between them, these relations result in behaviour and other states. This assumes that mental states (propositional attitudes) are entities with causal power. The Turing test - How do we establish whether a human or a computer can think? In the Turing test, a computer is programmed to try to get you to think that it actually is a human. If a machine succeeds in fooling you, it has passed the Turing test. According to Turing, passing the test means that the computer is capable of thinking. Cognitivism - Functionalism thus accepts the idea that mental states are causally related to input, output and other mental states. They are also multiply realizable. Functionalism believes that mental states are defined by what they do rather than what they are made of. Computationalism builds on functionalism by adding a specific claim, thinking is a form of computation (mathematical calculation). - When we combine these two views, functionalism’s idea that mental states are causal roles, and computationalism’s idea that thinking is symbol manipulation, we get cognitivism. - This means that human cognition can, in principle, be simulated by computers. From the perspective of cognitivism, computers should, in principle, be able to think. - If our minds are properly realised Turing machines, we can understand the mind because we can understand Turing machines. Unfortunately, there are reasons to think that the cognitivist model is not the right model for cognition. - Cognitivism = machine functionalism - Classical AI is committed to cognitivism, implementing these ideas in artificial systems. The first robots - In the late sixties a robot called Shakey was developed. Shakey’s mind was detached from its body, the information would be sent to a computer that would process the pictures taken by the robot, and would make a plan outlining how the robot could go from A to B. - Since his mind was clearly detached from its body, we have a very good example of the model that was used. 1. The pictures are fed to the computer (input) 2. Rules are used to create a detailed representation and a plan (information processing and planning) 3. This plan (output) is sent back to the robot and it moves. Problems with machine functionalism. 1. Shakey’s computer took a really long time. As a model of thinking this is not biologically realistic. If an animal had to calculate this long, it would probably become predator’s prey. 2. Second problem with machine functionalism also shows that it is not a biologically realistic model of thinking: it processes information in a serial fashion. In the Turing  machine, if an error occurs in any of the steps or if there is damage to a single piece of the machine, then the entire process will come to a halt. Thus, this way of processing information has a low damage tolerance and is therefore biologically not very realistic as a model of the mind. If a neuron dies in a human brain, it will have no effect on the functioning of the brain. 3. Machine functionalism follows the filling cabinet method: you put all the information in the system before you let the system interact with the world. This method is biologically unrealistic, we are not born that way. 4. John Searle argues that a computer that has the appropriate set of rules to manipulate symbols will not be able to actually understand anything. Of course, one of the important aspects of thinking is that one understands what one is thinking. So if he can show that a machine passes the Turing test does not understand anything, he demonstrates that the computer cannot think. - Searle does not speak Chinese. Now imagine him sitting in a room with a book that contains a large set of rules. Every now and then, he gets a piece of paper that contains some Chinese characters. He looks these characters up in his rule book. The book specifies that that he should write down certain characters in response to that certain set. He passes his note to someone standing outside the room. Now suppose the input (in Chinese), was a question, and according to the rule book he gives the correct answer (in Chinese). A native speaker it would look like he understood the question and gave the right answer. But Searle does not speak Chinese. Note that the rule book has a table: if X then Y. So if a set of rules does not generate understanding, and understanding is key to thinking, a computer that passes the Turing test does not understand anything by virtue of only the computer program running on it: syntax (rules) does not mean semantics (meaning). 5. Problem with the Turing test as a test of thinking is that animals that cannot read and write will not be able to pass the test. Does it just mean that, for example, chimpanzees cannot think? No it does not, it just means that they cannot think like humans can. Functionalism VS behaviourism - Functionalism is not a sophisticated version of behaviourism. While behaviourism does not talk about internal states at all, functionalism, on the other hand, believes that mental states are internal states with causal power. - Functionalism accepts mental realism. Mental realism being a concept that believes mental states are real and have an objective existence, independent of external validation. Connectionism - If we want to have a biologically realistic model, our approach should be one that tries to stay as close as possible to how the neurons in the brain are connected and how they process input. This is what connectionism does. - For philosophical connectionism, mental states should be understood as patterns of activity in a network of interconnected processing units. These networks operate in parallel, rather than following a step by step sequence like in traditional computational models. - Intelligence arises from the collective interactions of many simple processing units, rather than from a single central processor - Connectionism does not reject mental realism (the idea that mental states are real), but it constrains how we should think about them. Instead of viewing mental states as discrete, symbolic entities, connectionism suggests they emerge from dynamic, distributed patterns of neural activity. Biological networks - In a biological neural network, it is important to understand how neurons receive and transmit information to other neurons thorough synapses. - The dendrites are treelike and receive information from other neurons. The locations where they receive the information are the synapses. The signal does from these synapses to the cell body and from there it goes to the axon and the axon terminals. This is where more synapses are located, and the signal is transmitted via neurotransmitters like dopamine and serotonin to other neurons. - Inspired by biological networks, artificial neural networks follow similar principles. An artificial neuron is called a unit and it receives input and sends away output. Consider a network that consists of an input layer, an output layer and a hidden layer in between. The input units all have connections to all the units in the hidden layer, and these in turn all have connections to the output layers. - Activation value depends on: a) Degree of activation of units in previous layer b) Weight of the connection c) Activation function Logical network - Suppose we want to make a network that models the logical operator “and”. We want the output unit to give output only if it gets some input from both input units. These units of course only send a signal if they receive some input. - In this example we will be working with only 0 or 1. The output unit has a total input of 2. Suppose that the signal is not inhibited nor amplified when it is forwarded to the output unit. We then need to set the threshold of the output unit to 2, and to model “and”. - Supposing we lower this threshold to 1. The output unit now fires when it receives inout from either one of the input units, or from both of them. This model then models the (inclusive) “or” - “AND” - two input units and one output unit with the threshold of 2 - “OR”- two input units and one output unit with the threshold of 1 Exclusive disjunction - One of the major early problems of connectionism was that simple neural networks struggled to perform certain types of computations that classical AI could handle easily. - These early neural networks couldn’t solve the XOR problem (exclusive disjunction), which is a type of decision making that requires understanding non-linear patterns- meaning problems that can’t be separated with just a straight line. - To fix this researchers added hidden layers between the input and output. These extra layers help process more complex relationships in data. Backpropagation is a learning method that corrects mistakes step by step by adjusting the connection strengths (weights). If the network makes an error, back propagation sends that error backward through the layers, helping the system learn over time. It involves presenting the network with a sample input and then adjusting the connection weights in such a way that the network’s response to the input is improved. This is repeated over and over, with more samples presented and more adjustments. Back propagation is the learning algorithm that allows us to reduce error or the difference between the current output and the desired output. Neural network that detects mines - Gorman and Sejnowaki were inspired by the auditory system. There were three ranges of frequencies: low, medium and high to analyze the volume of a sound across these, - There would be a powerful echo of a mine at low frequencies, not at all at medium, and so-so at high frequencies. Face recognition and snapshot reasoning - The connectionist neural network recognises faces from a picture. Thus it could be argued that this is snapshot reasoning. It judges whether this one input is a face and gives just one output. It does not deal with any changes in time. - This problem can be solved by creating a loop in the system through the addition of an extra layer: a recurrent network. If information is then sent from the hidden layers to the output units and some other units called context units, these context units feed the information back to the hidden layer a moment later - In this way, a kind of short-term memory is created, which enables the system to respond to real time changes in input, and it will also be able to respond appropriately, even when the input is distributed for a while. Post connectionism - Even though it is biologically inspired, there is a significant difference between the performance of connectionist networks and the brain. Particularly in connection to the models of learning of connectionist networks. 1. Lack of anatomical evidence. The brain uses a combination of electrical and chemical signals, while artificial networks rely on mathematical weight adjustments. 2. Number of repetitions requires for learning differs dramatically. Artificial networks need massive amounts of repetition to learn something, often requiring thousands or millions of training examples, humans don’t. 3. Catastrophic interference, solutions found for new cases interfere with the solutions found to the old cases. In humans new knowledge doesn’t erase old knowledge, we can learn skills without forgetting old ones. - More recent developments aim at addressing these limitations, by developing alternative learning algorithms, and developing training strategies… However, these are engineering problems with engineering solutions. Core ideas on what neural networks are and do remain the same.  Deep learning Evaluation of connectionism - It has some advantages over cognitivism (classical AI) that also show that it is a biologically more realistic model: - An economical manner of representing- The same units and connections are used to store/activate different representations. This is a very economical manner of storing data, you do not need new units to store new representations, they are distributed. - Tolerance to damage- Since the system is parallel and not serial, damage to just one unit will not have large implications. The system gradually breaks down when units are damaged, graceful degradation, and it has a high damage tolerance. - Pattern completion- neural networks can perform well even when they have incomplete input, even in cases with incomplete input, output might be correct. Meaning patterns are completed. - Free generalisation- the upshot is that semantically related items are represented by syntactically related patterns of activation. Implications of connectionism 1. Theoretical- if representations in the brain are distributed, then we can no longer think of representations as distinct entities. This means that propositional attitudes do not exist, in the classical sense. If you learn something new, this means that you also change what you had already learned. 2. Practical implications (biases)- networks are trained rather than programmed. What they learn is only as good as the training data. For instance, neural networks tasked with and trained for face recognition face problems with biases related to gender and race. Neural networks inherit biases from us based on biased information on which they are trained.