Philosophy of Mind Lecture Notes PDF

Philosophy of Mind 8 QUESTIONS ABOUT THE CONSCIOUS MIND Lecture 1: What is Philosophy? 1) as conceptual analysis o Manifest World view: W. Sellars (everyday world view)/ Scientific World view 2) As conceptual clarification o What does someone mean by their con...

Philosophy of Mind 8 QUESTIONS ABOUT THE CONSCIOUS MIND Lecture 1: What is Philosophy? 1) as conceptual analysis o Manifest World view: W. Sellars (everyday world view)/ Scientific World view 2) As conceptual clarification o What does someone mean by their concept? (just like conceptual analysis) o Goes further: looking at science to tell us more about these concepts (short term vs long-term memory) 3) As a science of validity o Ask whether the concepts are used well? Can we make inferences/ distinctions? (Causality and observations based on models – everything can’t be observed) 4) Is a training in changing your perspective o Considering other opinions to get a more complete idea 5) Is searching for truth o Sophists were concerned with winning, not with finding the truth (vs. Socrates, concerned with finding the truth) Philosophy for psychologists Philosophy is critical thinking in a certain field of study (in this case psychology) o Thinking critically for example about for example ethical questions, mind/psyche, consciousness, … The hard problem o How the brain can give rise to experience (?) ▪ Consciousness is in some way physical Question 1: What is the conscious mind? “Consciousness is the biggest mystery. It may be the largest outstanding obstacle in our quest for a scientific understanding of the universe (David Chalmers) An initial classification:  1. Conscious experiences ▪ what-it-is-likeness (Nagel) 2. Cognition ▪ Cognitive states have intentionality (aboutness) 3. Emotions ▪ Have both a qualitative character, and intentionality Taking the mind seriously Experiences, and feelings are examples of mental states, these states for together the conscious mind A preliminary characterization of the conscious mind Qualia = qualitative aspects of experiences o The qualitative aspects of phenomenal experiences Phenomenal experiences = how something is experienced Cognitive states = possess intentionality o Intentionality = the property of being about something, also called aboutness there might be mental states that do have intentionality without having a single quale o Thus, at least conceptually, we can distinguish those mental states that are characterized by qualia and those that are characterized by intentionality Emotion = possess what-it-is-likeness and aboutness The conscious and the unconscious mind The relation between the conscious and the unconscious mind is that the states of the unconscious mind can become conscious given the right circumstances The mind-body problems central mind-body problem = how does the conscious mind fit into the physical world 1. How do phenomenal experiences fit into the physical world? 2. How do cognitive states fit into the physical world? 3. How do emotions fit into the physical world? o We actually have only two problems because the three mental states are just defined by two properties (qualia and intentionality) 1. How do qualia fit into the physical world? 2. How does intentionality fit into the physical world? Consciousness and cognition The term cognition is used to refer to the part of the mental states that have aboutness The term consciousness is often used to refer to the phenomenal states of the mind, mainly because cognitive states are mental states that can also be conscious states Question 2: Can the mind function separately from the brain? “Only fools are certain and immovable.” (Michel de Montaigne) “I am really distinct from my body and can exist without it.” (Rene Descartes) “It is widely granted these days that dualism is not a serious view to contend with, but rather a cliff over which to push one’s opponents.” (Daniel E. Dennett) Michel Eyquem de Montaigne Skeptic o we can never be certain about anything o we will always have to postpone our judgments “you cannot be sure of anything; any claim was open for doubt” Did not claim anything (‘if you say that there is nothing you know for certain, you are already making a knowledge claim’) Descartes’ method of doubt Not satisfied with the skeptic belief and desired true knowledge Method (adapted from Skeptics): doubt everything Not sure about his physical existence (demon that deceives him into thinking that he had a body or that there is a physical world) The only think he was sure about: the fact that nothing is certain Descartes’ foundation Argues that no matter how powerful the evil demon is. he cannot have him doubt his own existence o If you doubt, you think. And if you think. you have to exist - for how else can you think o Cogito ergo sum Difference to Skeptics: he knows that he exists and that he is a thinking being Cogito (ergo sum) is not an argument but an insight o Means that whatever he perceives clearly and distinctly is true Further conclusion and proof for god’s existence: he has ideas, one of those is an idea of god (the most perfect being). He could not be the origin of this idea (for he is imperfect), it had to have come from god o God is able to deceive him but will not do so because deception = imperfection (therefore he is certain that he is both mind and body and a physical world exists) Substance dualism Mind and physical body are substances o Essential property of the thinking substance (res cogitans) is that it thinks (not extended; does not have place in space)  ▪ Essential property of the physical substance (res extensa) is that it is extended (three dimensional, it has a place in space; there can only be one physical object at a certain place in space at a particular time) ▪ Physical bodies are moved by collision (bumping into each other and setting each other in motion) o Can exist independent of each other (e.g. rock without mind but with body, ghost without body but with mind) Essential properties o The essential property of the thinking substance is: thinking o The essential property of the extended substance is: being extended / having extension o Being extended means that it takes up a place in space o Movement is the result of collisions Humans consist of the two substances, animals are machines (only physical things without a mind) ▪ Human body is a machine which is closely related to the mind (pain experience when body is damaged, that’s why we usually think of the mind and body as a unity) Princess Elisabeth Descartes: "the only person I have so far found who has completely understood all my previous published work” Descartes corresponded with her and she questioned him The Patrick Swayze problem Elisabeth pointed out the interaction problem: o How can the physical body and the non-physical mind interact with each other? Name because of: GHOST the movie Descartes’ response to the problem Pineal gland causes soul and body to influence each other (soul has the power to move animal spirits in the pineal gland and those then transfer the movement to the rest of the body) o Only explains location of the interaction, not how it occurs o One explanation: heaviness moves a body towards the enter of the earth; soul can move body in a similar way o Conclusion: it is incomprehensible how the mind and body interact Occasionalism and parallelism God is in some way responsible for the interaction Different interpretations: o Occasionalism= the only cause of any event in the world is god; natural  causes are not true causes, but occasional causes (occasional cause: an event that is an occasion for god to cause another event) ▪ Causal interaction between soul and body is impossible, it merely seems that there is interaction but really god is the cause between two events (e.g. sees mental event of someone wanting to lift arm, then causes the change in the body so person raises arm) o Parallelism= will and motion (e.g. of wanting to speak and tongue motion) exist parallel to each other without having a causal relation ▪ Will and movement depend on the same supreme designer who has made them in such a way that they run parallel to each other) ▪ If we have two clocks that run in sync, that is because they have been made that way Same applies to the mind and the body Problem from both: How does God do this? Problems with this “common sense” idea of a bodyless mind (Movie GHOST) Q1: Why do the ghosts not fall through the metro (or the Earth for that matter)? Q2: Why is Sam Wheat afraid of the coming train? Q3: The ghosts are depicted as 3D-objects with a specific location (viz. humans) – why?; Q4: Did Wheat’s clothes die as well? The Űbermistake: o through the pole; o through the door; but o the ghost bumps his head to the next door; Hence: Our common sense concept of a soul is conceptually incoherent – the little princess was right Parapsychology investigate the paranormal: accept from the start that parapsychological phenomena exist o the separabilily thesis is accepted by default An alternative way to consider parapsychology is to see it as the science that investigates claims about paranormal phenomena o like the claims that some people have precognition Clairvoyance alleged ability to gain information in a way that does not use normal senses (extrasensory perception ESP) o ESP: seen as evidence that mind can function and exist separately from the body Electronic Voice Phenomena Electronic Voice Phenomena (tuning a radio/tv channel between two stations and recording the white noise, through which you can discover messages from the dead) Lecture 2: Idealism & Behaviorism The solution to the interaction problem according to Berkeley is easy: there is no interaction, for there is only mind To be more precise: There is no material substance This is a form of monism Question 3: Is there only mind? “I see this cherry, I feel it, I taste it, and I am sure nothing cannot be seen or fell or tasted; it is therefore real Take away the sensations of softness. moisture. redness. tartness. and you take away the cherry. Since it is not a being distinct from sensations, a cherry, I say, is nothing but a congeries of sensible impressions. or ideas perceived by various senses, which ideas are united into one thing (or have one name given them) by the mind because they are observed to attend each other." (George Berkeley) Monism Berkeley= There is no interaction, for there is only mind Substance monism= the view that there is only one substance, not two o Is there is only one substance, there is are no substances that can interact, that means that the interaction problem disappears Different versions of monism: 1) Materialism or physicalism= everything in the world is physical, everything is material or made out of matter (also the conscious mind) 2) Res cogitans or thinking substance 3) Idealism= everything in the world is mental, needs God (George Berkeley) John Locke Empiricists claim that we can only gain knowledge about the world via sensory experience. o Properties don’t exist without perceivers Primary and secondary properties o Primary properties don’t depend on perception o Secondary properties depend on its perceiver Substance A quality is a property. and a property is always a property of something o But we only perceive the properties, not the thing that has all those properties Locke maintained that there was u substance underlying the primary properties o But - as an empiricist how could he know?  Rene Descartes as a rationalist, he used his ratio to come to the conclusion that these properties are the properties of the res extensa Locke should have said that, as an empiricist, he could not have knowledge of this substance, for there is no way to perceive it with our senses Are there no primary properties? When we assume that colours, warmth, tastes, smells, etc. are secondary qualities, we have to wonder of the primary properties as classified by Lock are not also secondary properties? To be is to be perceived George Berkeley is an empiricist o so he holds the position that all our knowledge stems from sensory experience o esse est percipi = to be is to be perceived o Unthinking thigs don’t have any existence outside of the minds that perceive them o Physical objects don’t have primary properties and there is no physical substance ▪ GB: If something is big, that is dependent on the observer ▪ GB: Hence, height is also a secondary property ▪ GB: This goes for all properties o Berkeley’s ideas are central to idealism but also to immaterialism, because the denies the existence of material substance o His dining of substances doesn’t mean that he also denies matter ▪ Matter is dependent upon the mind that perceives it: matter is that which is seen, felt and tasted However, there is no underlying material substance Another way to prove the existence of God Barkeley’s view: Question 4: I there only behavior? Behaviourism: focus only on observable behaviour does not accept unobservable mental entities (there are no subjective mental  properties) All behaviour is reflex-like in nature Treat behaviour like a Black Box: input goes into the black box (stimuli) and output comes out if it (behaviour) Psychological (methodological) behaviourism: science should use an objective method so that all observations could be verified independently [Watson, Skinner] o Human thought is human behaviour (Skinner, more radical than Watson) o Goal: the prediction and control of behaviour o Science has to be objective (only describe input-output relations) o In contrast to introspection (Wundt, Titchener) ▪ Problems: observations could only be made by the subject; is subjective & it is impossible to study the mental life of animals as they cannot report on their mental life o Studying the correlation between stimulus (input) and behaviour/response (output) Watson’s little albert o Watson thought that emotions could be understood in terms of stimulus- response correlations Philosophical behaviourism (analytical or linguistic) o Ryle: we cannot establish whether animals (or other humans) have minds (vs. Descartes: animals are mindless machines) Ryle is against Dualism ▪ ‘We make this distinction between conscious and nonconscious things based on behaviour, so it’s better to study behaviour than to think about this immaterial mind’ ▪ The mind is to be analysed in terms of dispositions; if you ask where the mind is besides those dispositions, you’re making a category mistake (categorizing something in the wrong category) ▪ Dispositions: a behavioural pattern that one displays under certain circumstances (e.g., sugar cube dissolves in water) ▪ Ryle: the mind-body problem is a pseudo- problem, that originates from the category mistake people make, when they think that the mind is something more than dispositions to behave Logical Positivism ▪ Interested in meaningful statements, against meaningless, pseudo-sciences and introspection (subjectivity)  ▪ Empiricists: based on observations! o Churchland: ‘any sentence about a mental state can be paraphrased, without loss of meaning, into a long and complex sentence about what observable behaviour the person would show’ -> so could be translated into dispositions o Problem: impossible to define the disposition, the description will be too long and even if it is very long it will probably leave things out (is not equivalent in meaning) o E.g., John has toothache = if we would offer him painkillers, he would take them -> however the hurt is left out and this is what it is all about o E.g. the thinker: thinking does not translate into any behavioural dispositions The behaviourist dilemma: either to deny that there was more to the mind than behaviour, or to acknowledge it and thereby undermine behaviourism o If behaviourists accepted that there is a mind/ consciousness apart from behaviour, it would mean that they do not study the mind by studying behaviour (would go against the principle of behaviourism) Behaviourists leave out qualia but also intentionality (‘for how can they analyse thinking in behaviourist terms?’) Behaviourists are not able to come up with paraphrases that entail all possible dispositions, they leave out the qualia and are not able to analyze thinking in dispositional terms Lecture 3: Another type of monism Materialism or physicalism = Monism #2 o You could also argue that the other substance (the res extensa) is the only substance there is o That way there is no interaction problem o And you might not insert God in the theory when it becomes really difficult o The identity theory is a variety of materialism Question 5: Is the conscious mind part of the brain? “Sensations are nothing over and above brain processes” (Jack Smart) Taking both the mind and science seriously The identity theory is a kind of materialism o Materialism= the position that the world is material or physical, and that all things that exist are thus in some way physical. ▪ Term is usually reserved for realist theories regarding the conscious  mind (theories that take the mind seriously) that accept that everything in the universe is material or physical ▪ if there ls a substance at all. there is only the physical substance In some sense, behaviourism is a version of materialism, because it argues against dualism and therefore, accepts only material entities Mind-body supervenience Materialists, who are realists about the mind, have to accept the idea that the physical determines the mental, just like the physical determines, for instance, shape Supervenience = one set of properties determines another set of properties (Lego) Mind-body supervenience = the claim that mental properties are supervenient on the physical properties and the relations between them (minimal demand) Supervenience base: the physical Supervenience properties: the mind Any two things that are exactly alike in their physical properties must therefore have exactly the same mental properties (The star trek assumption) ▪ “Physical indiscernibility entails psychological indiscernibility” (Jaegwon Kim) An analysis of the concept of identity Identity theory was the dominant mind-body theory in the 1960’s (Jack Smart, Ullin T. Place, David Armstrong) Central thesis of the identity theory: o All mental states are identical to certain brain states ▪ We can reduce mental states to brain states ▪ It is a mistake to think that MBIT is an eliminativist view of the mind ▪ In some views, a mental state is thought to involve more than just a brain state Three meanings of the term “identity” 1. Personality identity= who am I? o Not used in the mind-body debate, even minds always belong to persons 2. Qualitative identity= similar in some aspects but not all o Not used in the mind-body debate either 3. Quantitative or numerical identity= “Two” things are actually one and the same thing o The identity theory is concerned with quantitative identity, for it is a theory about the relationship between mind and brain Ullin T. Place “It’s not about providing a definition, but it is an empirical matter: we have discovered (or better: we will discover), that mental states are certain brain states” Contingent truth: can be denied without resulting in a contradiction  It is a truth that is not a necessary truth: for all we know it could have been otherwise if we have discovered that a = b, then this is a necessary truth (in other words: it could not have been otherwise) Leibniz’ law = if “two” things really cannot be discerned from another, then they must be one and the same thing o 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 o important because it provides us with a strategy used by opponents of the identity theory Kripke on identity Identity statements are necessarily true (so they are not contingent truths) “water” is a rigid designator o In every possible world our word “water” refers to the exact same stuff ▪ Goes for all identity claims He argued against the contingent statements Contingent statements A priori: you can establish the truth of a claim by mere thinking (you do not need to do empirical research) A posteriori: you can establish the truth of a claim only by doing research in the world, aren’t necessarily contingent Mind-body Identity theory: all mental states are identical to certain brain states o identity relation is symmetrical identity relation is symmetrical o this is why "certain" is added in the description of the position of identity theorists: Every mental state is identical with a brain state. but not every brain state is identical with a mental state ▪ Thus, all mental states are (certain) brain states, but not all brain states are mental states Reductive materialism Reductive materialism= reduction of mental states to brain states (another term for the identity theory) o if brain states are real, mental states are real The notion of reduction comes from the layered model we tend to use in thinking about the world o Lowest level or layer of reality as consisting of elementary particles o At a higher level we have atoms o At the end level we encounter molecules o Other levels would include cells, groups of cells, organisms with a central  nervous system, organisms with brains, groups of organisms, societies etc. ▪ The idea is that at some levels, new properties com into existence that did not previously exist at a lower level 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 o If mental states can be ontologically reduced to certain brain states, it follows that psychology can be theoretically reduced to neurology A classical error When we identify a mental state with a brain state and thus reduce it to a lower level. many people have the false intuition that this means that the mental state does not 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 exists o If we can reduce a mental state on a brain state, we identify the mental state with the brain state ▪ If we say A=B, and B exists, A has to exist So we didn’t eliminate the mental state with that ▪ Eliminating the term, doesn’t eliminate the state o We can only eliminate terms reducing A to B, is not eliminating A o If one is able to show that A can be reduced to B, we have a reason to believe that A exists. and that if A cannot be reduced to B that could be seen as a reason to believe B does not exist o This is an empirical matter ▪ if we can’t reduce a mental state to a brain state, then it does not exist (so we have to investigate that for each and every mental state) Reduction vs. eliminativsm “[T]hese are the end points of a smooth spectrum of possible outcomes, between which there are mixed cases of partial elimination and partial reduction. Our empirical research […] can tell us where on that spectrum our own case will fall.” (Paul Churchland) Type physicalism Type identity theory or type physicalism = every individual case (a token) of a certain mental category (a type) is identical to an individual brain state of a certain category MBIT: “Pain is C-fibre-firing” (let’s assume we discovered this) Usually MBIT is regarded in the following manner: type physicalism This means: every token (individual state) of the type pain is identical to a token of the type (say) C-fibre-firing An empirical question  If a mental state is identical to a certain brain state, this has to be an empirical discovery Whether mental states can be reduced to certain brain states is an empirical question, and therefore a scientific question Correlations between mental states and brain states These days, there are many different ways of studying the correlation between mental brain states Philosophical arguments in support of the identity theory William of Ockham o Principles of parsimony= “entities must not be multiplied without necessity” = Ockham’s razor ▪ When confronted with two different, but equally good, explanations for a phenomenon or event, we should choose the ontologically more parsimonious one ▪ Being realists about the mind & being nonreductionist is ontologically not very parsimonious ▪ It’s more parsimonious to accept that mental states are just certain brain states Jack Smart o Used Ockham’s Razor to argue for his brain process theory o He argued that a statement about a sensation is also a statement about some brain processes o He also argued that it is very strange that everything in the entire universe can be explail1ed in terms of physical processes except the conscious mind ▪ According to those he argued against (the dualists, accepting that behaviourism is not an option), the conscious mind is something "over and above” the physical processes Causal role analysis One way of getting at identity claims is to employ causal role analysis (David Armstrong) 1. What does the relevant mental state do? o For instance, pain is the result of tissue damage and causes organisms to focus on that damage while also causing them to be stressed 2. What it is that fills this causal role? o As it turns out, this is the complex brain state that we have called activity in SCIC ▪ Hence, we can identify pain with this activity in SCIC Arguments against the identity theory 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 the properties of the brain state are properties of  the mental state In order to see how we can argue against MBIT, we need not only Kripke’s ideas, but also those of Leibniz o Leibniz’ law= Two things x and y are identical if and only if all properties of x are properties of y, and all properties of y are properties of x ▪ if x has a property that y does not have (or vice versa): x ≠ y Lecture 4: Functionalism it doesn’t matter what the brain it made of, the only thing that matters is his function mental holism= Mental states are states that play a causal role between 1. input 2. output 3. mental states Functionalism vs. behaviourism functionalism sounds a bit like behaviourism, but it tells us about what is in the “black box” functionalism accepts mental realism (behaviourists doesn’t want to talk about it) o mental states are internal states with causal powers o The functionalist is a realist with respect to mental states Functionalism vs. MBIT The model of MBIT: 1. What is the causal role analysis of X? 2. That which fulfils this role IS X o Here we see the interpretation of supervenience of MBIT The model of functionalism: 1. What is the causal role analysis of X? 2. That which fulfil this role REALIZES X o Here we see the alternative interpretation of supervenience What is intentionality? o It is always something Old idea: (some) mental states have intentionality o Folk psychology ▪ We assume that other people have mental states and intentionality to do something  New idea: mental processes are computational (Turing) Question 6: Can machines have conscious minds? Thinking machines Multiple realizability= the idea that mental states can be constructed in different ways and mad of different stuff o Fatal for the identity theory Functionalism= “machines can have a mind as well” Consciousness chauvinism Identity theory argues for consciousness chauvinism (= only creatures that have human brains can have a conscious mind) When humans are in pain our neocortex is active o Fishes don’t have a neocortex ▪ Does that mean they can’t experience pain? o If fishes are able to experience pain it implies that there are different ways to experience pain ▪ So the mental state would be multiple realizable The “is” of identity is symmetrical and transitive Machine functionalism Functionalism= clams that mental states are constituted by their causal (or functional) relations to sensory input, other mental states, and behavioral output o the position that first took multiple realizability seriously Mental state= a functional state in the sense that it does something, that it has causal impact on the behavior of the organism Machine functionalism (a type of functionalism) Turing: “computers can think” Can machines have conscious minds? Functionalism old idea: o Mental states have intentionality Folk psychology= the common sense psychology that we use in everyday life to explain and predict the behavior of other people PA= propositional attitude o In folk psychology and philosophy of mind accepted as the stereotypical mental state with intentionality Each PA is a mental state on its own (Ramsey, Stich, Garon) o PA’s are also functionally discrete states Cognitivism Functionalism accepts the idea that mental states are causally related to input, output and other mental states o They are also multiple realizable Computationalism= cognition consists of a set of mental states that are symbolic representations and that thinking is the manipulation of the representation according to certain rules or algorithms Cognitivism= functionalism + computationalism o From this perspective computers should be able to think If our minds are properly realized Turing machines, we can understand the mind because we can understand Turing machines o but there are reasons to think that the cognitivist model is not the right model for cognition Shakey the robot Robot build in the late sixties that was able to go from A to B by taking pictures of the surrounding and then calculation a detailed map and navigate in there (the calculation took one to eight hours) o Not a biological realistic model of thinking, because if animals would work like this they would probably be death really quickly Serial processing Second problem with machine functionalism: o It processes information in a serial fashion ▪ It has a low damage tolerance (if something breaks noting functions anymore) Biologically unrealistic o If a neuron dies in a human brain, it won’t have an effect on the brains function John Searle’s Chinese room argument Even if a computer ever passed the Turing test it wouldn’t mean that it can think, because it would only have the appropriate set of rules to answer (John Searle) o Compared to the Chinese room experiment If you measure the ability of thinking in a computer with being able to answer questions, you would say that animals can’t think (at least not like humans) Is the mind multiply realizable? If a certain type of mental state can be realized by human brains and by rainbow trout brains, then this mental type can’t be identical to any type of brain state o The identity theory has to be false When do we classify the realization bases of two things as different enough to claim  multiple realizability? If we have different stuff realizing the same properties needed to realize the mind, then this is not really a case of multiple realizability If there is just one way of realizing a mind, then the identity theory would be back in the game Functionalism is an alternative for identity theory o But if multiple realization is the basis for the argument in favour of functionalism, it isn’t a strong argument Brain-centric Another problem with functionalism: o Is the brain really the only thing that belongs to the base of the conscious mind? Exit artificial intelligence? Functionalists argue that artificial intelligence is possible o Problem: it’s biologically unrealistic ▪ The model is based in syntax, but that doesn’t lead to semantics Connectionism as an alternative to cognitivism Connectionists come in two types: 1. Scientists wo actually build brain-like networks 2. Philosophers wo argue that these connectionist models provide insight into how the mind works (Churchland) Neural networks Neurons= the main type of cells in the brain, send information to other neurons and other types of cells o The message consists of electrical pulses and neurotransmitter o They have some (cell body) and two extensions (dendrites & axons) Dendrites= receive information from other neurons o Synapses= location where they receive the information Signal goes from synapses to cell body, from there to the axon and the axon terminals o Unit= artificial neuron, it receives input and sends away output ▪ Input units all have connections to all the units in the hidden layer, and these in turn all have connections to the output units Information that comes into the system, is thus processed in parallel ways ▪ The different values put together form a vector The signal can be inhibited or amplifies  o Depends on the different strengths between the units: the weights A logical network Suppose you want to make a network that models the logical operator “and” o We could do it with just two input units and one output unit o We want the output unit to give output only if it gets some input from both input units o These units of course only send a signal if they receive some input Face recognition Cottrell made a network that could scan pictures of faces o Input layer of 64 by 64 units o 80 hidden units and 8 output units Backpropagation= when knowing what the output should be it is possible to adjust a weight and see if the output vector changes in the right direction Gradient descent learning= step by step the computer fine-tunes the connectionist network The result of this trial and error process if backpropagation was that, in the end, the connectionist network was able to recognize the faces it had been trained to recognize Snapshot reasoning Snapshot reasoning= recognizing faces from a picture o It judges whether this one input is a faces and gives just one output o It doesn’t deal with any changes in time This problem can be solved by creating a loop in the system o A recurrent network If information is then sent from the hidden layers to the output units and some other units (context units) feed the information back into the hidden layer a moment later o This creates a kind of short-term memory, 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 disturbed for a while Evaluation For cognitivism, it has become clear that that model is biological not realistic (it is to slow), so it can’t teach us about the conscious mind The filing cabinet method is biologically unrealistic o you put all the information in the system (the machine table) and only then you let it interact with the world ▪ This is biologically not realistic: we are not born like that Connectionism says much closer to the way the brain is structured and is biologically more realistic than cognitivism o Connectionism is a clear improvement over cognitivism Structure and semantics In the cognitivist view, two pictures take up two separate parts of the memory In the connectionist model, representations are superimposed and don’t need to use a new part of the memory system Syntax and semantics are closely related in connectionist networks o And totally unrelated in cognitivist model Rethinking representations If connectionism is the proper model for mental states, then our beliefs about the world are not functionally discrete If connectionism is right, propositional attitudes can’t exist, and thus should be eliminated from our ontology Problems for connectionism It is related to the idea that PA’s are real and functionally discrete is that thought systematic o This means that thought, like language, is rule-based and uses direct concepts or word ▪ We do not find this systematicity in the connectionist networks but in the classic cognitivism (Fodor, Pylyshyn) Brain-centric Functionalism is a brain-centric view of the conscious mind o This is also true for connectionism oNot clear nor evident that this is wrong or true Conclusion Connectionism is biologically more realistic that computer functionalism If it is correct, we might have to abandon our folk psychology notions of propositional attitudes, but that does not eliminate representations Functionalism is not biologically realistic Functionalism can’t explain semantics Now we have seen that functionalism is an alternative to MBIT that takes MR seriously, we need a theory that does that too, but without the problems of functionalism: connectionism Lecture 5: Connectionism Connectionism: Also a version of physicalism that takes MR seriously (at least at first sight) and claims to be biologically more realistic It is an alternative to the classical serial approach to intelligence and information processing  Other terms: Parallel distributed processing (PDP) and neural network theory Compare biological and artificial networks Units are the AI "neurons", they receive input and send output o The strength of this output is different for each unit and depends on the unit the output is sent to: this is called the weight (which can be amplifying or reducing) o The units are connected to each other in a parallel manner Example: logical neurons: o Units have a threshold o Idea: every function of proposition-logic (like “and” and “or”) can be implemented in a PDP network o It’s a simple network: two input units I1 & I2 and an output unit O o The input units both send a signal to the output unit, which has a threshold of 2.0 o (No variable weights for the input units: if the input is 1, the output is 1 as well) o O only becomes active if it gets input from both I1 & I2 Example: detecting mines o How to recognize a mine from within a submarine? 1. Determine the strength of the frequency 2. Use this as input for PDP network 3. Train the system via backpropagation Gradient descent learning Example: face recognition Lecture 6: Question 7: Is Google Maps part of the conscious mind? The Frankenstein hypothesis  Frankenstein hypothesis= we don’t need to take the non-brain parts of the organism or its environment into account in order to understand the place of mind in the world o Who we are, what we think, experiences is determined by the brain, the rest of the body is just there to keep the brain alive ▪ Applies to: mind-brain identity theory, functionalism, connectionism Embodied and embedded theory= non-brain parts of the body and aspects of the environment can be used to solve cognitive problems o Challenges the idea that cognitive states have intentionality Extended mind hypothesis= parts of the brain and the environment are not only used to solve cognitive problems, but belong to the cognitive mind Cognition Said earlier: cognitive mental states have intentionality or aboutness o Only part of the answer Biological cognition= the evolved ability of an organism to solve problems thrust upon that organism by its environment o Practical or theoretical knowledge Putting brain, body, and the world together again Embodied and embedded view: o The mind is not something that can be neatly separated from the (rest of the) body and the environment o Biological organisms actually use their brains, bodies and the outside world o Processing of information doesn’t depend on the manipulation of symbolic representations in accordance with rules Embodied cognition = your cognitive capacities of an organism are determined, or at least heavily influenced, ty the type of body it has o E.g. our notion of “in front of” and “in the back ” are determined by the type of body we have and where our exes are positioned o Example of the serial killer that had another y chromosome and a problem with the liver that he produced less serotonin ▪ So his killing was strongly influenced from his body Embedded cognition = cognitive capacities of an organism are determined, or at least heavily influenced, by the type of environment it lives in o Secondary qualities Making a jigsaw puzzle Epistemic action= actions that change the environment in such a way that they help cognitive processes Embodied experience Embedded experience Conclusion Embodied and embedded theory is right o Frankenstein hypothesis if false Rethinking cognition: non-mental cognition The embedded and embodied view of cognition criticizes cognitivism precisely for its idea of cognition as symbol manipulation Cognitive states can be either mental or non-mental If we accept that cognition comes both in a mental and in a non-mental form, then the part of cognition that belongs to the conscious mind can still be characterized as being about something If we consciously solve problems, we do need representations: o Conscious cognition is characterized by aboutness Four criteria for the extended mind Parity principle= if a part of the world functions as a process in the performance of a task which, if it were done in the head we would undoubtedly recognize as part of the cognitive process, then this external process should be regarded as part of the cognitive process The eternal system counts as a part of someone’s cognitive mind if it is: o Reliably available and typically invoked o Deemed to be trustworthy and thus the information is automatically endorsed o It is easily accessible when its needed Otto, Inga, Leonard, and Clive Some brain states are not conscious and can’t become conscious, and thus are not mental states Other states are unconscious but can become conscious, and thus there are mental states that belong to the unconscious mind Telephone numbers and Google maps Conclusion and preview Question 8: Can the problem of consciousness be solved? Mind the explanatory gap Joseph Levine: There is a gap between the physical and the phenomenal  o Impossible to explain qualia in terms of physical properties because: 1. Homo sapiens is not equipped with the appropriate cognitive capacities, this is why we have an epistemological gap in our explanation 2. The world is very different from the way physicalists think it is: Physicalism is false and thus any physicalist theory of consciousness will be unable to explain how qualia fit into the world o The ontology is ultimately the reason for the gap in the explanation: ▪ There is actually a gap between qualia and the physical world If that were the case, we would have to rethink dualism What is it like to be a bat? Thomas Nagel arguments: There is an epidemiological gap o This doesn’t necessarily imply that physicalism is false ▪ Other animals also have phenomenal experiences, some are alike to us What is it like to be a bat? o We can’t know, because: only you know what it is like to be you Phenomenal experiences are subjective Any scientific explanation of any phenomenon has to be objective He doesn’t see how we can ever be able to explain the subjectivity in objective terms Is Nagel’s argument fatal for physicalism? No, because it doesn’t say that it can’t be done, or that we should conclude that physicalism is false o We just don’t know Mary the superscientist Frank Jackson: Came up with an argument that purported to show that there are actually non-physical facts in the world and that therefore physicalism (dealing with only physical facts) has to be incorrect o Did this by presenting a very strong intuition pump o Jackson bases what he calls the knowledge argument on the intuition that is flushed out in this intuition pump Knowledge argument= is physicalism is right, there are no non-physical facts Thought experiment about Mary the super scientist: Mary= a scientist who lives in the future  o In that future our scientific theory about colours is complete and Mary knows everything about it ▪ But: Mary has lived in a black and white room all her life Will Mary lean something new if she would go outside? o She will gain knowledge about qualia Is Jackson’s argument fatal for physicalism? Several problems with this argument o The first comes from himself: the argument is based on an intuition, and intuitions can be wrong o Since we never know who’s intuition is right, we shouldn’t use intuition to try and solve this matter o The knowledge argument is based on an intuition that is possibly wrong ▪ The demand of this argument to a theory of the phenomenal mind is too harsh Hence: the knowledge argument isn’t fatal for physicalism Daniel Dennett: If Mary knows all the physical facts about color, then she also has knowledge about the physical facts of what colors look like Zombie twins Zombie thought experiment: suppose that there is an exact copy of our universe in a parallel universe o David Chalmers uses this to argue for his vision of dualism: ▪ In that universe, there is an exact physical copy of our planet ▪ So you have a physical duplicate on Planet Zombie and your zombie- twin is doing exactly the same thing as you ▪ But twins in the duplicate world do not have phenomenal experiences: they are phenomenal zombies There is nothing it is like to be a zombie o But since they are physically indiscernible from us, they act the same ▪ This means that phenomenal experiences can’t be physical and if there are not physical than physicalism is false Is Chalmers’ argument fatal for physicalism? Objections against Chalmers’ argument: o The existence of zombies might be impossible o His thought experiment is designed in the way that if you believe it, you have already accepted dualism The importance of the phenomenal zombie  Zombie intuition pump not convincing as a basis for an argument against physicalism o But the thought experiment is still a major importance to the debate because: 1. Those who encounter this experiment for the first time have string intuitions that zombies can’t exists Even though it is a thought experiment that is meant to flush out a dualist intuition, it flushes out just the opposite intuition in many cases 2. It could also be viewed as a challenge to the materialists why zombies are conceivable but not possible Easy problems and a hard problem Easy problems: we have a perfectly good scientific method of solving them o E.g. how can we store and retrieve information or how can we use language Property dualism Natural dualism is a version of property dualism Property dualism= the view that mental and physical states and events might not be different substances, but different properties o There could be one substance, and that substance then has two sets of totally different properties Natural supervenience Chalmers distinguished between logical and natural supervenience Logical supervenience= when you have lower-level properties and their relations, it is necessary that you also have the higher order properties Natural supervenience= if some supervenient properties are naturally superventient on other basis properties, then it could be the case that there is another world in which the basic properties are present, but where the supervenient properties are absent If phenomenal properties can’t be functionally analysed, then it will be impossible to either identify them with physical states or show how they are realized by them (Chalmers) Fundamental property= a property that can’t be in any way reduced to something else or explained in any other terms o Just like some physical properties in our world are fundamental (e.g. mass or spin), the phenomenal properties are fundamental too o Even though there are fundamental, they do depend on the physical Panpsychism Double-aspect principle= whenever there is a physical information in our universe there is also phenomenal information o Information is defined as a differences that makes a difference Reprise: is Chalmers’ view fatal to physicalism? Big problem: it is by no means clear that zombies are an ontological possibility  You can’t claim that a phenomenal experience is both causally inefficacious as well as still relevant to your phenomenal judgments Panpsychism= the idea that phenomenal properties are all around us o Chalmers’ naturalistic dualism leads to that Are we just not smart enough? Arguments by Nagel, Jackson, Chalmers show that physicalism is a problematic view, but not that it is false o Colin McGinn agrees ▪ He believes that a naturalistic, scientific theory of consciousness should be possible ▪ Also that humans are just not smart enough to understand how physicalism can be true ▪ We are cognitively closed for the solution of the mind-body problem Is McGinn’s view fatal to physicalism? He makes the claim that there is an epistemological gap that we can’t solve o He doesn’t claim that there in an ontological gap between the mental and physical o Although this argument is pretty strong it’s not fatal for physicalism ▪ Its fatal to our efforts to actually find the right physicalist theory and understand it The natural method Owne Flanagan: to make progress on mind-body issues, we need to use an interdisciplinary method (= natural method) o We have to take reports from humans about what they experience (their phenomenology) o We also have to take into account what psychologists have to say and what neurologists have discovered The natural method applied to depression Depression is characterized primarily by prolonged sadness, self-blame, a sense of worthlessness and an absence of pleasure Neurology has provided us with insights about the hormonal disbalances in the brains of people with depression o This knowledge provides us with the insight that certain drugs can be used in the treatment In order to find out what the precise relations are between mental, and embodied and embedded brain states, we need to combine different disciplines