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AQA Philosophy – EpistemologyHYPERLINK \l "aquaintenceabilitypropositional"What is knowledge? HYPERLINK \l "tripartitetheor" The tripartite theory of knowledge HYPERLINK \l "jointsufficiency" joint sufficiency & Gettier InfalibilismNo false lemmasReliabilism Virtue epistemologyHYPERLINK \l "DirectRealism"Direct Realism HYPERLINK \l "indirectrealism" Indirect Realism HYPERLINK \l "idealism" Berkeley’s idealism HYPERLINK \l "conceptinnatism" Plato’s InnatismLocke’s empiricism vs Leibniz’ InnatismHume’s empiricism HYPERLINK \l "intuitionanddeduction" Descartes’ Intuition & Deduction thesisThe limits of knowledgeWhat is knowledge?Acquaintance, ability & propositional knowledgeThe nature of definition (including Linda Zagzebski)How propositional knowledge may be analysed/defined.The object of knowledge and the components of knowledgeZagzebski claims that knowledge is a ‘highly valued state in which a person is in cognitive contact with reality’. Knowledge is therefore ‘a relation’ between ‘a conscious subject’ and a ‘portion of reality’ with which the knower is ‘directly or indirectly related’.Zagzebski claims that acquaintance knowledge is direct knowledge of something through experience. It includes knowledge of persons and things but also my own mental states which are usually regarded at ‘the most directly knowable portion of reality’.Propositional knowledge is known by a true proposition about the world. It has been more discussed than acquaintance knowledge because it can be communicated from one person to another in a much more straightforward way than acquaintance knowledge can, if it can at all. Some philosophers also regard reality to have a ‘propositional structure’ or that propositional knowledge is at least the ‘principle form in which reality becomes understandable to the human mind’.Zagzebski notes that the nature of truth, reality and propositions are metaphysical questions about the object of knowledge which epistemologists usually avoid, instead focusing on the nature of the state of knowing. So accounts of knowledge focus on the conscious subject side of the relation.‘knowledge is a relation between a conscious subject and some portion of reality, usually understood to be mediated through a true proposition, and the majority of epistemological attention has been devoted to the subject side of that relation. In the state of knowledge the knower is related to a true proposition. The most general way of characterizing the relation between the knower and the proposition known is that she takes it to be true, and this relation is standardly called the state of belief.’The knowing state is a ‘species’ of the belief state. There were two issues that are widely viewed as having been overcome with that claim however:1 – knowledge and belief have distinct objectsThis has been resolved by viewing propositions as obects of belief as well as of knowledge so that same proposition can be either known or believed.2 – it is appropriate to restrict the range of belief to epistemic states evaluatively inferior to the state of knowledgeThis is resolved by viewing belief as ‘thinking with assent’, since to know propositionally is to take a proposition to be true. ‘So knowing is a form of believing’True knowledge is not just desirable but praiseworthy. Sometimes even a lack of knowledge is considered blameworthy, such as when we criticise someone by saying they ‘ought’ to have known better. Knowledge is good sometimes in a moral way. Plato characterised its goodness as noble. Zagzebski claims the definition of knowledge must ‘adjudicate’ the sense in which knowledge is good.Defining knowledgeZagzebski claims that some different views of knowledge arise from different aims people have for knowledge. Definitions can serve many purposes, e.g. practical (identifying instances of contingent knowledge and helping us get it) or theoretical (a necessary truth about whether the concept of knowledge is to be placed on the conceptual map of philosophy).One ‘common theoretical purpose is Locke’s claim that we can give concepts a real definition, a ‘necessary truth that elucidates the nature of the kind of thing defined’. There are some concepts defined by necessary truths with no such independent investigable nature though, such as ‘bachelor’ which is defined as necessarily ‘an unmarried man’. Natural kinds are categories of things which exist in the natural world independently of human thought, e.g. human being, gold and water.Zagzebski claims that knowledge is obviously dissimilar to such natural substances and yet Philosophers often aim for such a ‘real definition of knowledge’, though often only implicitly. She suggests that ‘perhaps knowledge is not in an ontological category for wThe tripartite theory of knowledgeThe tripartite definition of propositional knowledge can be derived from Plato’s dialogue Theaetetus. It holds that propositional knowledge is true justified belief: s knows p iff (if and only if):1. p is true2. s believes p3. p is justified.This definition of knowledge claims that these three criteria together are equivalent to knowledge. They are individually necessary; meaning all three are essential for knowledge, and jointly sufficient; meaning if you have all three, you have knowledge, no further criteria are necessary.On the tripartite view, J T & B are individual necessary for having knowledge which means that if one is not present then knowledge cannot be possible. A case where knowledge is had while nonetheless lacking one of those three criteria would therefore be a counter-example to the tripartite view.Truth.Step1: Zagzebski, in her article, ‘What is knowledge’, claims that knowledge is a particular type of mental contact with reality. Since reality is ‘everything that is the case’ (to use Wittgenstein’s phrase) i.e. what is true, and knowledge is supposed to be of reality, that provides reason for the criterion of truth.Critiquing the individual necessity of truth:Step 2: scientific knowledge is what we currently have most reason to believe based on the available evidence at the time. This means that it changes over time. E.g. In the early 1900’s Physicists believed the universe was static and eternal, whereas today most believe it is expanding and began at a point in time at the big bang. This is because more evidence has been gained. Perhaps yet more will be gained to change the current view of the origin of the universe. Scientific knowledge might therefore be false and so seems to be a case of knowledge without truth.Step 3: If knowledge could or indeed is false, then arguably it cannot be knowledge. It seems absurd to say we know something, yet it is false. Step 4: Science can make planes fly. It clearly works. There are some false assumptions because some planes crash, however there must be some knowledge.Belief.Step 1: The idea of the mind connecting with reality also provides reason for the criterion of belief since if your mind does not make contact with reality then it seems difficult to see in what sense your mental content might be connected to reality.Critiquing the individual necessity of belief:Step 2: A student learns an answer to a question and then forgets it. In an exam, the question comes up and the answer surfaces in their consciousness, seemingly from nowhere to them, though it happened to have triggered their memory without their realising it. They decide to write it down as they have no better idea, though as they thought that answer popped into their mind from nowhere, they do not believe it is right. Arguably this is knowledge without belief.Step 3: Having your memory associate an answer with a question is arguably not the same as truly knowing something. In order to know something, arguably you have to know that you know it. Justification.Step 1: Justification is the reason or warrant for a belief. Reasons, and so justifications, can be good or bad. Seeing something with your eyes is a good reason, and so justification, for belief in it. Seeing something within a dream is not. There are a variety of types of bad justification such as irrationality, mistakes, logical errors & ignorance. Zagzebski claims that we think knowledge is good, namely desirable. Having knowledge is difficult as it requires an apparatus of mental abilities but because knowledge is valuable to us, that makes the knower worthy of praise and esteem. It is possible to have a true belief which was not justified if it was gained due to luck/chance, e.g. horoscopes, reading tea leaves or palm reading. True belief can also be gained by irrationality, such as being convinced that someone is a librarian due to seeing them read a book. If they turned out to in fact be a librarian, that would be true belief but not justified because not all book readers are librarians. Luck and irrationality will occasionally produce a true belief, but philosophers would rather explain such events with the phrase ‘a broken clock is right twice a day’, rather than confer the praise and esteem of ‘knower’ to the believer in such cases. This provides justification for regarding justification as a criterion for knowledge.Critiquing the individual necessity of justification:Step 2: Knowledge of our immediate perceptual awareness. E.g if I am looking at a red thing. To claim there really exists a red thing in an external world would require some justification, however merely to know that I am having an experience of redness arguably requires no justification since it is known immediately with no process of reasoning or inference. Step 3: If it is possible to doubt my existence then that would cast doubt on the claim to know my immediate perceptual awareness. joint sufficiency & GettierGettier cases attempt to show that justified true belief can occur due to epistemic luck. We wouldn’t want to call that knowledge because then knowledge would be dependent on luck, but therefore the tripartite view is incorrect and the criteria need to be added to in order to somehow rule out the problem of epistemic luck. That means J T & B are not jointly sufficient.Original Gettier case 1: Smith and Jones are waiting for a job interview. Smith gains a justified belief that Jones will get the job, perhaps because the president of the company assures him of that. Smith then sees that Jones has 10 coins in his pocket and so formulates the proposition “the person who will get the job has 10 coins in his pocket”. However, it then turns out that Smith gets the job and that smith happened to have 10 coins in his pocket. The proposition Smith formulated was true, he believed it and had justification for it. It seems he therefore had justified true belief and yet he only arrived at it due to the epistemic luck of happening to have 10 coins in his pocket. This means it is possible to have justified true belief and yet we wouldn’t want to say it was knowledge, therefore the joint sufficiency of the tripartite definition is undermined.Original Gettier case 2: Smith has the justified belief ‘Jones owns a Ford (car)’ from which he justifiably, through disjunction introduction, concludes that “Jones owns a Ford, or Brown is in Barcelona. If, in fact, Jones does not own a Ford but due to luck Brown really is in Barcelona, then Smith had true justified belief, but we wouldn’t want to say it’s knowledge, so again the joint sufficiency of the tripartite definition is undermined.InfalibilismStep 1: Infallibilism is the view that knowledge must be certain. Descartes’ infallibilism holds that knowledge must be indubitable. Infallibilism strengthens the justification criterion of the tripartite definition of knowledge to indubitable justification. Smith’s justification for his belief was not infallible as the president could have been wrong, lying, testing him or a hallucination. Step 2: Infallibilism is overly restrictive as arguably nothing can be known beyond all doubt.Step 3: Descartes’ thinks the cogito is knowledge which cannot be doubted.no false lemmasStep 1: A false lemma is a false step in reasoning or which is not explicit in a proposition but which, if one exists, is discovered by analysing the assumptions which underlie a proposition. Smith made the assumption that the president of the company was correct in saying he would get the job. That was a false assumption and therefore a false lemma. The argument is that cases of epistemic luck involve false lemmas, so adding ‘no false lemmas’ as a fourth criterion to make JTBN therefore creates a definition of knowledge which is not susceptible to Gettier cases.Step 2: Arguably no false lemmas just becomes infallibilism because to know for sure that you have made no false assumptions requires that you know all relevant things with certainty. reliabilismStep 1: Reliabilism replaces the justification criterion with ‘reliably formed’. A belief is reliably formed if it is produced by a process which produces a high percentage of true beliefs. Perception and memory are examples. They can produce false beliefs but they usually i.e. reliably produce true beliefs. E.g a sea captain on a ship in medieval times knows that a compass will reliably point to north. They cannot offer any justification for how the compass works so they have no justification for thinking it points north. However they have observed that it reliably points to north most of the time and so can have reliable knowledge without justification.Step 2: Goldman’s Barn facades. Henry is driving through the Barn County, a countryside where there are lots of fake barns which look real when viewed from the road. Whenever viewing a fake barn, Henry thinks “there is a barn”. Vision is usually a reliable process, but in Barn County, it only produced a reliable belief by accident. Step 3: Goldman suggested adding another condition to reliabilism to overcome this difficulty. Henry cannot distinguish between what he believed to be true – that he was in a barn county – and the relevant possibility which would make his belief false – that he was in a fake barn county. Adding this criterion of being able to distinguish between relevant possibilities to reliabilism will solve the barn fa?ade problem.Truth tracking. Nozick suggested that instead of formed by a reliable process, reliable could mean tracking the truth. That means that you know X is true if you would not believe X were it false virtue epistemologyResponsibilist Virtue epistemology regards intellectual ‘traits/virtues’ such as intellectual courage, attention to detail and desire for truth as virtuous in that they enable us to achieve knowledge. They replace the justification criterion with ‘virtuously formed’. You have knowledge if you have truth, belief and the belief resulted from intellectual virtues.Sosa illustrates this with an archer shooting an arrow at a target. The arrow could be shot badly by an incompetent archer yet still hit the target. That is knowledge produced by luck. The arrow could be shot well or “adroitly” yet still miss. The arrow could even be shot well, be blown off course, and then blown back onto course. That is still not an example of the arrow hitting the target because of the skill of the archer. The true belief did not result directly from the intellectual virtues.Sosa argues that knowledge occurs when a belief is true as a direct result of the believer’s use of intellectual virtues – he calls that ‘aptness’.Henry’s one true belief in barn county is the result of luck, not because of his intellectual virtues, therefore virtue epistemology can say it’s not knowledge.Step 2: How can one ever know for sure that their knowledge was gained because of their intellectual virtues? It seems ineradicably possible that luck played a role which the knower was unaware of. Direct RealismDirect realism is the common sense intuitive view that the objects of perception are physical objects which exist independently of our minds. We think of Physical objects as existing objectively in space and time. If I am in a room and perceive some physical objects in it, then when I leave the room they remain as they are unless they are undergoing some sort of physical process like burning which would cause them to change when I wasn’t there to perceive them.Direct realism claims that our senses perceive those physical objects and their properties. For example, when perceiving the physical object of table, I perceive it’s properties such as color, shape, size, smell and texture. Direct realism therefore claims that sense data is veridical – coinciding with reality.Direct realism issue #1: perceptual variationStep 1: Bertrand Russell argued that what we perceive in sense data is not the same as what is in reality and so direct realism is false. Russell points to the example of a shiny, brown table. He argues that the color of the table actually depends on where you stand in relation to it. There is light falling on the table making a part of it shiny and therefore white in color in a certain spot, but if another person were to stand at a different place to you, that white spot would appear to them to be on a different part of the table than where it appears to you. Therefore, where one person sees the table to be white, another might see it to be brown. A particular spot on an object cannot be two colors at once, therefore color cannot be a property of the table. So direct realism is false for claiming the properties we perceive are necessarily properties of the physical object.Russell argues this can apply to texture too, since while the table feels smooth, on a smaller level it actually has indentations and grooves. Shape is also perceptually variable since it depends on the angle at which you view the table as to whether it looks rectangular.Step 2: The direct realist could alter their claim to be that perception is veridical in the case of a normal observer under normal conditions. There is no perceptual variation if we keep the conditions (such as lighting and relative position to object) the same.Direct realism issue #2: IllusionStep 1: If you look at a straight stick submerged in a glass of water, the light-refracting properties of water make it look bent. An illusion occurs when an object (the stick) appears to have a property (of bentness) yet in reality it does not have that property (It isn’t bent). Therefore, the perceived illusory property is sense data which exists in the mind, not reality. Illusions appear just as real as normal veridical perceptions – they are subjectively indistinguishable. Therefore, normal perceptions must also be of sense data in the mind, not of physical objects. So direct realism is false.Step 2: The direct realist could argue that we are directly perceiving the light-refracting properties of water. We are therefore seeing the true reality of how a stick looks due to the reality of how light and water interact. So the direct realist could argue that the stick has the property of ‘looking bent’. It is possible for something to have the property of ‘being straight’ yet also ‘looking bent’ so there is no inconsistency. Step 3: Hallucination. Perceiving a property which an object doesn’t have is an illusion but perceiving an object which doesn’t exist is a hallucination. So the direct realist response of step 2 will not work for hallucinations as there is no object which has the property of ‘looking like X’.Direct realism issue #3: HallucinationStep 1: Hallucination occurs when sensing an object which doesn’t exist. Therefore what we perceived must be mind-dependent sense data. Hallucinations are subjectively indistinguishable from normal veridical perceptions, therefore normal perceptions must also be of sense data, not mind-independent physical objects. So direct realism is false.Step 2: disjunctive theory of perception. A disjunction is when there are two possible ways something can be. It is either one or the other. Hallucination is very different from normal veridical perception as it involves a mind separated from reality. Therefore this case is disjunctive as it must be either/or – it cannot be both – the mind is either connected to reality or separated. So, what we perceive is either a hallucination or veridical perception. Just because those two possibilities appear the same, it doesn’t mean they are the same. In fact, since they are disjunctive, they cannot be the same. Therefore, just because hallucinatory cases are of mind-dependent sense data, it doesn’t follow that all perceptions are mind-dependent sense data.Direct realism issue #4: Time-lag argumentStep 1: It takes time for light to reach us from an object we perceive. The light from the stars we see in the sky may have taken billions of years to reach earth. So we see those stars as they were billions of years ago, not as they are now. Although the objects of perception we more regularly see are much closer, like a table or chair, the light still takes some time to reach us. Therefore, we are not seeing the objects of perception directly, we are seeing them as they were in the past. Therefore, direct realism is false.Step 2: The direct realist could claim that we can still perceive objects in the past directly as long as we are perceiving them as they actually were. So when viewing objects, we are directly seeing them as they were in the past.Step 3: Some might argue that direct has to mean instant, not just accurate.Indirect RealismIndirect realism is the view that the objects of perception are a mind-dependent representation which is caused by external mind-independent physical objects. Sense-data is perceived immediately (directly) whereas physical objects are perceived indirectly. The representation can be different from the object it represents. The argument from perceptual variation, illusion and hallucination, which try to show that what we see isn’t necessarily the reality, argue for indirect realismRussell defines sense-data as the ‘content’ of our immediate sensory perception. John Locke’s primary/secondary quality distinctionIndirect Realism issue #1: Scepticism about the existence of mind-independent objects.Step 1: If all we perceive directly are sense-data, then we never perceive the mind-independent objects which Indirect realists claim are giving rise to that sense-data. There is a ‘veil of perception’ between our sense data and the external world ‘behind’ it which we cannot see through. In that case, it seems we can’t actually know that mind-independent objects exist at all. If we can’t see through the veil, how do we know there is anything on the other side at all? Indirect realists it seems assumed the external world must be there to cause our sense-data, but there could be another explanation for the existence of sense-data than that. What reason have we got to think a mind-independent external reality is the correct explanation for sense data?Russell’s response: The existence of the external world is the best hypothesis. Step 2: Russell argued we can neither prove nor disprove either the claim that the external world exists and causes my sense data, or the claim that the external world does not exist and so does not cause my sense data. Since we cannot prove for certain either claim, we are left with making a hypothesis (a theory which is confirmed or disconfirmed by experience or reason). Russell argues the question then becomes which possibility – that the external world exists or does not – is the best hypothesis.Russell points to the example of a cat. When first you glance, it is in a corner of the room. The next time you look, it is on a sofa. If there is no external world, then the cat just disappeared from one place in perceptual experience and then appeared in another. However that does not provide an explanation of the experience as there is no reason why that should happen. If we take the other hypothesis, that there is an external world so the cat is a mind-independent object which continues existing when unperceived, then we have an explanation of our sense data of the cat having moved to the sofa – it walked there when you weren’t looking! Since this hypothesis explains our sense data, Russell argues it is the best hypothesis.Step 3: Russell seems to assume that what provides a better explanation of our sense data must be what we have most reason to think true.John Locke’s argument from the involuntary nature of our experience.Step 1: Locke argues that perceptions from sense experience have a key difference to perceptions from memory or imagination in that we have no choice over what we perceive in sense-data. However, we can choose what to remember or imagine. If there really were no external world causing our sense-data, then everything must be in our mind. In that case, we should expect to have choice over perceptions from sense experience. However we do not – if we look at a bottle of water we have no choice but to see one. Yet if we want to imagine a bottle of water filled with gold or remember the last time we drank from one, we can. Since we have choice over perceptions which originate from our mind yet we have no choice from those from sense experience, it follows that perceptions from sense experience do not originate from our mind but from an external world.The argument from the coherence of various kinds of experience (Locke & Cockburne).Locke also argues that sense-data from different senses back each other up. E.g if I see an apple, I can touch it to see if it also feels like one, and taste it to see if it also tastes like one. Locke combines these two arguments in the example of changing how paper looks by writing on it – so sight and the sense of your hand moving cohere. You cannot cause the words to appear on the paper by mere imagination, you have to actually write. Once it is written, it cannot be changed except by further writing. If someone else read out what you had written, there would be coherence between your auditory (hearing) sense-data and what you thought to write. Lock argues this ‘leaves little reason for doubt’ that there is an external world.Step 2: Arguably however Locke hasn’t proven that there is an external world of physical objects, he has merely given some reasons as to how it makes sense of our sense-data for there to be one. Locke claims the fact that we have no choice over our sense-data perceptions shows they are not a part of our mind. However, this is to assume all parts of our mind are under our control. There might be some reason unknown to us why sense-data originating from our mind isn’t under our control. There might also be some reason why we get the same information from different senses, despite them also potentially originating from our mind. Step 3: Indirect realism can still be backed up by Locke’s arguments if we use Russell’s notion that it is the best hypothesis. The existence of the external world is the best explanation of lack of choice over perceptions and the coherence of various senses.Catherine Cockburn also responds to scepticism about the existence of mind-independent objects with an argument from experiential coherence. She first points to the radical difference between experiences gained from different senses. E.g. The sound a waterfall makes is not just different to but of a very different sort than the visual experience of it. Cockburn then points out we learn to pair visual and auditory experiences together such that we are able to make an inference from one to the other. If we are walking on a mountain and hear a waterfall, we can infer and accurately predict what it looks like; and vice versa, if we see a waterfall from far away, we can infer and accurately predict what it will sound like when we have moved closer. The fact that we can accurately infer and predict our experiences suggests that there is some mind-independent object which both senses perceive yet is independent of any particular sense. If it could be heard without being seen and seen without being heard, then it seems to follow it exists without being seen or heard, i.e. mind-independently.Indirect Realism issue #2: Scepticism about the nature of the external worldStep 1: Scepticism about the existence of the external world questioned whether indirect realism could provide a basis for thinking there is an external world beyond the veil of perception at all. However, there is a further criticism which remains even if an indirect realist can make a case for that existence, which is to question whether they can provide a basis for claiming that we can know anything about the nature of that external world. This attacks the Indirect realist claim that objects of perception are representations of mind-independent objects. How can they know such objects are representations, or indeed have any link whatsoever, to the actual objects in the external world? How do they know the external world is even composed of anything like an object?The argument from George Berkeley that we cannot know the nature of mind-independent objects because mind-dependent objects cannot be like mind-independent objects.Russell’s argument depends on sense data in our minds being caused by physical objects. Imagine a physical fire causes light to enter our eyes which sends signals to our brain. How does that give rise to sense data though? Berkeley argued it’s not clear how something can transform from a physical mind-independent thing into a mental mind-dependent thing. That seems to be what is required for anyone who claims the external world is mind-independent though, including Russell here.Berkeley’s idealismBerkeley thought all that existed in the world are minds and ideas. Attack on Primary & secondary quality distinction.Berkeley argues that our sense data is immediate, so their cause must be inferred. We do not perceive the cause of our perceptions. Berkeley repeats Locke’s illustration that a hot hand feels room temperature water to be cold yet a cold hand feels the same water to be hot. Since the water cannot be both hot and cold, the feeling of heat cannot be intrinsic to the water. Berkeley thinks this is true for color too.Berkeley argues against the direct realist attempt to suggest that e.g sound is a vibration of air, since vibrations are seen or felt, not heard.Having established that secondary qualities are mind-dependent, Berkeley then argues that primary qualities are also mind-dependent because they are perceptually variable.Things can look larger or smaller depending on the size of the observer or the distance of the observer from the object. Smooth things can appear rough under a microscope. Shapes can look different depending on the angle they are seen from. Animals that think faster than us perceive motion slower than we do. Berkeley concludes that the mind perceives qualities only, not primary nor secondary ones.We do not perceive anything that is independent of the mind.Berkeley makes a second argument that primary qualities are mind-dependent. He argues that to think of a physical object of any size or shape will require that it have color. If you had a black ink pen and a black piece of paper, you would not be able to draw a shape on it of any size. We can’t separate the idea of size and shape from secondary qualities. Therefore, size, shape and color are not separable. Therefore, it cannot be that size and shape are primary while color is secondary.Locke response: a blind person is able to imagine size and shape without color. Locke also argues that when we perceive a primary quality, we see the physical object as it exists independently. So Locke shows this argument only works if Berkeley’s other arguments work.Berkeley’s third argument is that we can never know what is behind the veil of perception. We never see the ‘thing-in-itself’, to use Kant’s phrase. So if the size of a table is a quality of it, then in itself it must have no size since the quality only exists in our perception. Therefore the claim that the thing-in-itself is beyond our perception leads to scepticism. We cannot know whether the objects of perception at all represent the true reality, or even if there actually is a true reality.The Master argument. Berkeley claims that if you can conceive it to be possible that something mind-independent could exist, then he will ‘grant it actually to be so’. Hylas claims in response to be thinking of a tree that exists without anyone perceiving it. However Berkeley points out that by stating it thus, Hylas has conceived of that tree and thereby made it mind-dependant. Berkeley then argues that the cause of our perceptions must be a mind, not matter. We know that minds can cause ideas in others. If I say ‘think of the Eiffel tower’, then I can cause an idea in your mind. What we perceive are bundles of ideas. Ideas, however, are passive as they don’t cause anything. Only minds can do that. Therefore whatever causes our perceptions must be a mind. Berkeley also points to the complexity and systematicty of our perceptions. Matter alone has no reason to be organized and complex, so it’s more likely to be a mind.Berkeley finally argued that because we do not have control over the ideas we perceive, while we do have control over our imagination, the objects of perception do not originate from our mind. The only way to explain all this is our perceptions originate from God’s mind.To be blue is to look a certain way, not to actually possess any quality of blueness.Idealism issue #1: illusions Step 1: Idealism claims we perceive ideas directly as they are, so the stick in water really is bent.Step 2: Berkeley responds that what we see really is bent, but that we are mistaken if we infer that if we reached into the glass and felt the stick, it would not feel bent. So Berkeley claims illusions mislead our inferences made on the basis of what we perceive.Step 3: If we reach into the glass to feel that the stick is straight, while also looking at the stick appearing bent, then we will be perceiving two inconstant things at the same time. The stick cannot be both bent and straight. Therefore, one must merely be an appearance while the other is the reality, and so there is more to reality than what appears. Therefore idealism is false.Step 4: Berkeley responds that this is a mistake in the language we use to talk about the situation. When we say ‘the stick is bent’ what Berkeley argues we really mean is that it would look bent under normal conditions, which is clearly false. Berkeley suggests instead saying “the stick looks bent”, which is clearly true. Idealism issue #2: hallucinationsStep 1: A hallucination is the perception of an object which doesn’t exist. Since Idealism claims that the objects of perception are directly perceived ideas, it seems impossible according to idealism for a hallucination to exist since to be is to be perceived. A hallucinated object is perceived, therefore it exists and so is not really hallucinated.Step 2: Berkeley argues that hallucinations result from the imagination. While the imagination normally produces voluntary and relatively dim perceptions which are not vivid, Berkeley argues that at times it can produce involuntary and vivid percpetions. Berkeley argues hallucinations also lack logical connection to the rest of our experience. Step 3: Some hallucinations might be logically connected to the rest of our experience however. Someone with a fever might look out a window and hallucinate a person walking down the street. There is nothing illogical about that and so no way to tell.Step 4: Berkeley only needs to explain how Idealism could account for the existence of hallucination however, not give us a method for telling which perceptions are hallucinatory. His response that they come from the imagination, as shown by hallucinations usually being unconnected logically to the rest of our experience, does explain that, even if there are some hallucinations which are logically connected. Idealism issue #3: SolipsismStep 1: Berkeley’s arguments against objects being mind-independent logically leads to solipsism - the view that all that exists is my own mind. Step 2: Berkeley thinks we can know that God’s mind exists, so it can’t be only my mind in existence. The complexity and regularity of the ideas we perceive shows that they come from God’s mind. This alone counters Solipsism since if God’s mind exists then my mind is not the only mind. However, Berkeley also argues we at least have some evidence to justify thinking other people have minds too. We can infer that on the basis of our own experience of them.Metaphysical & epistemological solipsismIdealism issue #4: Whether God can be used to play the role that he doesStep 1: If I throw a lit match into an empty room and come back later, the room will have changed. On Berkeley’s idealism, however, it seems that the room ceased to exist as soon as I left it, since ‘to be is to be perceived’. Something that does not exist cannot undergo change. The room did undergo change however, which suggests Idealism is false. Berkeley solves this problem by claiming that God perceives the room and indeed everything other idea, thereby keeping them in existence regardless of whether any human is observing them. This seems to be relying on God however.Step 2: Berkeley claims that he is not relying on God but actually proving his existence, however. With his arguments against the primary and secondary quality distinction combined with his master argument, Berkeley thinks he has proven idealism – that the objects of perception are directly perceived mind-dependent ideas. That being the case, the only explanation of the changeability of ideas when no human perceives them is that there is a God which perceives them.Step 3: If Berkeley’s attack on the primary/secondary quality distinction and master argument fail to establish idealism, or if some other argument proves idealism false, however, then his inference of God would likewise fail.Plato’s InnatismPlato’s argument in the MenoStep 1: Socrates draws a square with a diamond inside on the ground in front of a slave boy who has had no mathematical teaching. Socrates then draws a diamond inside the square. The slave boy is able to explain, or correct himself when making a mistake, that the sides of the 8ft square are equal to the length of the diagonal of a square that is 4 square feet.Since the slave boy had no mathematical education, Socrates concludes he must have been born with the knowledge. He then argues that the only way to make sense of how that knowledge got there is if humans had a previous existence. Plato thinks that previous existence is the world of forms, where our souls existed before becoming trapped in this world of appearances. Step 2: An empiricist could respond that we gain the concepts of number and shape from experience and then gain mathematical knowledge when analysing those concepts. The slave boy may not have had any mathematical training, but he had seen shapes of objects in his life – thereby gaining concepts of shape and geometry. The knowledge is therefore gained via analytic a priori reasoning about concepts gained from experience. Step 3: The empiricist in step 2 is assuming that mathematical truths are analytic. If that were the case we could never ‘discover’ new mathematical knowledge, it would be merely worked out on the basis of mathematical concepts we knew already. A person can know two numbers and know what multiplication is, yet not know what the two numbers multiplied together are. Yet if mathematics were analytic, they should know it just as someone who knows what a bachelor is knows that it is an unmarried man. Step 4: The empiricist could reply that mathematics is simply more complicated conceptually than the idea of a bachelor. It takes reasoning to grasp the full meaning of the concepts, but it isn’t discovering anything additional to what was already contained within those concepts. Locke’s empiricism vs Leibniz’ rationalist innatismStep 1: Locke believed the mind was ‘tabula rasa’ at birth so there is no innate knowledge. If there were, such knowledge would be universally assented to. However, children and idiots do not know supposedly innate propositions such as ‘something cannot be and not be at the same time’ or ‘something cannot be black all over and white all over’ or ‘whatever is, is’. Locke also argued that even if there was something that was universally assented to, that wouldn’t necessarily make it innate. There could be some other explanation of how everyone came to know something other than it being innate. So universal assent is a necessary but insufficient criterion for innate knowledge.Step 2: Leibniz responded to Locke’s ‘children and idiots’ augment by claiming that people can have knowledge even if they can’t express it. We can tell by the way children and idiots nonetheless manage to act and behave in the world that they must ‘unconsciously’ adhere to such necessary truths as ‘something cannot be and not be at the same time’. Additionally, Leibniz argued that innate knowledge could require some sort of unlocking or triggering process by interaction with experience in order to be consciously known. Leibniz illustrated this with a block of veined marble where the veins happened to form the outline of a statue of Hercules. A stonemason would merely need to hit the block a little and then the statue would be revealed. The work of the stonemason is like experience and the statue is the innate knowledge. It might look like experience is causing the knowledge but really it is just activating the pre-existing innate knowledge. Leibniz thinks he can prove this knowledge could not have come from experience and must therefore have been innate by pointing out that propositions such as ‘something cannot be and not be at the same time’ are necessary, as they cannot fail to be true. We never experience anything necessary (must exist) – only contingent things (could exist or not exist). Therefore, our knowledge of necessary propositions must have been innate.Hume’s empiricismStep 1: Locke argued that the mind is ‘tabula rasa’ at birth – a blank slate with no innate concepts. He argues all our ideas come from either sensation or reflection. Sensation is when our senses experience objects in the external world. Reflection occurs when we experience the ‘internal operations of our minds’.Step 2: The sensation of yellow is quite different from the concept of yellow we gain from reflection however. Locke’s distinction doesn’t account for that. Hume proposed a different set of distinctions to solve this. Everything our mind directly experiences is a perception. Perceptions from the external world are impressions, perceptions from inside our mind are ideas. Ideas are usually less forceful and vivid. Something remembered is less vivid than the original experience (except in special cases like madness). This is because ideas are ‘faint copies’ of impressions. Ideas can be simple or complex. A simple idea is one which cannot be broken down any further, e.g redness. Complex ideas are combinations of simple ideas. A red rose is a complex idea made from the combination of the simple ideas of redness, the smell of a rose, the texture, and so on.Hume’s copy principle argues that all simple ideas are copies of impressions. All ideas in the mind therefore ultimately derive from impressions. Therefore, there are no innate concepts. Hume’s proof is to challenge anyone to think of a simple idea that was not copied from an impression. He also points out that lacking an impression results in a lack of the concept, e.g. someone blind from birth lacks the concept of color. Step 3: The missing shade of blue. Hume himself puts forward an exception to the copy principle, however. Someone who had never before seen a certain shade of blue would be able to conceive of it were they showed a list of all the other shades of blue, with the one they had not seen missing. The idea of that shade of blue would then not have been copied from an impression. Hume himself suggests this example is not significant, but arguably it is.Step 4: To defend Hume, one could claim ‘shades’ of blue are really complex ideas – mixtures of the simple ideas of blue, black and white. In that case, the missing shade of blue is conceived by the imagination in the same way as a golden mountain is conceived by joining the simple idea of gold and complex idea of mountain. Step 5: Philosophers disagree about how to break down complex ideas like knowledge, justice & beauty into simple ideas however. Either that is because the ideas and the method of acquisition of them are so complex or it’s that Hume’s theory is wrong.Intuition & Deduction thesis – DescartesThe meaning of ‘intuition’ and ‘deduction’ and the distinction between them.Descartes thinks we can gain informative (synthetic) knowledge through a priori means by intuition and deduction. Intuition is when the rational mind apprehends the truth or falsity of something with immediacy, which means without any process of reasoning or inference. The mind simply ‘grasps’ the rational rules by which we intuit that 2+2 necessarily equals 4. Descartes claims there is a ‘natural light’ of the mind which makes us recognize certain truths because we cannot doubt them. Deduction is using premises to reach a conclusion the truth of which is entailed by the truth of the premises. If we can know that the premises are true and that the conclusion follows deductively from them then we can know the truth of the conclusion. Descartes’ notion of ‘clear and distinct ideas’.Descartes claims that the cogito is apprehended by his mind in a special way which he calls clarity and distinctness. A clear idea is ‘present and accessible to the attentive mind’ – analogous to perceiving something visual clearly with our eye. An idea is distinct when it is so sharply separated from all other ideas that every part of it is clear’. Descartes claims that since the Cogito is a clear and distinct idea which he knows to be true, then clarity and distinctness must ‘as a general rule’ be a sign of truth. The cogito as an example of a priori intuitionStep 1: Descartes’ points out that we cannot doubt our own existence since that presupposes that we exist in order to do the doubting. We can therefore see that our existence is a clear and distinct idea intuited a priori.Step 2: Descartes’ then however points out that while we can know that clear and distinct ideas are true when we are apprehending them, it’s surely possible that they become untrue when we are not, perhaps because of God or an evil demon deceiving us. Therefore he feels the need to prove that is not the case.Step 3: To do that, Descartes first attempts to prove the existence of God with his ontological argument and the trademark argument.Empiricist responses to the cogitoStep 1: Hume argues that we only experience constantly changing mental states, not an enduring mental substance which could be the ‘I’ of the cogito, so we cannot know that there must be an ‘I’ which thinks. Hume argues that we wrongly and confusedly think that similarity of our mental states over time entails personal identity over time.Step 2: Descartes’ replies so this kind of argument by claiming it is clear and distinct that thoughts require a thinker.Step 3: Arguably Descartes is just influenced by the common sense ordinary experience of attributing thoughts to thinkers, but if he was truly doubting everything then why not the supposed link between thoughts and thinkers also?Descartes’ arguments for the existence of God as an a priori deduction.Step 1: The trademark argument. Descartes argues that the ‘natural light’ yields the causal adequacy principle - that there must be as much reality in the cause as there is in its effect. Just as something cannot come from nothing, neither can what is more perfect come from what is less perfect.He argues we imperfect beings are causally inadequate to create the perfect concept of God, therefore God must exist as the only causally adequate explanation of our concept of God.Step 2: evolution seems to violate the causal adequacy principle since it is an example of there being less reality in the cause as there is in the effect. The cause – single celled organisms – is lesser than the effect – humans. Step 3: However, it’s not quite the case that single celled organisms gave rise to humans. It was a combination of single celled organisms plus their environment, which together over billions of years resulted in humans. Empiricist responses to the trademark argumentStep 1: Hume argues that the concept of God is not innate but can be created by our minds. We start by imagining finite human qualities like goodness and imagine what they were like without limit by abstractly negating finitude/imperfection to create the concept not-finite/not-perfect, which is the concept infinite/perfect. We then combine goodness and infinite/perfect to imagine God’s omnibenevolence, and so too with God’s other attributes.Step 2: Descartes responds to this kind of argument by claiming that we couldn’t recognize imperfection as imperfection without appreciating that it was a lack of something which made it lesser than a standard of perfection which we must therefore already have an idea of. Step 3: Arguably the origin of the concept of perfection is merely a subjective preference for order over chaos since that typically enables survival which we have evolved to desire. It’s hard to see what objective basis there could be for perfection, but in that case the concept of God is only subjectively perfect which would not then place any constraints on its causal adequacy. Descartes’ proof of the external world as an a priori deductionThe existence of physical objects in the external world.Descartes claims he has a clear and distinct idea of a physical object as something that has extension and is changeable.His perceptions of physical objects are involuntary and cannot therefore come from his mind over which he has voluntary control. These perceptions are caused either by an external world, God or I simply have a tendency to have false beliefs which I cannot correct.If God, then God is giving us perceptions which do not map onto reality which would make God a deceiver. God is perfect by definition and therefore not a deceiver, so he cannot be causing my perceptions nor allowing an evil demon to deceive me by causing them.If God exists and is not a deceiver, he cannot have created me with a tendency to have false beliefs which I cannot correct.According to Descartes’ other arguments, God exists.So by process of elimination, the cause of my perceptions of physical objects in an external world is the existence of physical objects in an external world.Empiricist responses to Descartes’ proof of the external world.Step 1: Hume’s fork holds that ‘all objects of human reason or inquiry’ are either ‘relations of ideas’ or matters of fact. Relations of ideas, including intuitive analytic knowledge such as mathematics, are not dependent on ‘what is anywhere existent in the universe’. Their truth is therefore established regardless of what the universe was like. It cannot be denied without contradiction, since there is no possibility of it changing to be false since it does not depend on anything which changes (the universe). Intuitions of the relations of ideas therefore can not be about the world.Matters of fact are dependent on what happens to in fact exist in the universe and can be denied without contradiction since whatever happens to exist might have happened not to exist, which our minds can imagine. Hume claims a priori intuition and deduction only provides us with analytic knowledge of the relations of ideas, not synthetic matters of fact. Step 2: Knowledge of maths is arguably about more than just our own concepts.Descartes assumes that his perceptions must have a cause, but Hume argues that this cannot be established a priori since the claim ‘everything has a cause’ can be denied without contradiction and is thus not analytically true.The limits of knowledgeThe particular nature of philosophical scepticism and the distinction between philosophical scepticism and normal incredulity.Normal incredulity is doubt about commonplace everyday questions about human life and the kinds of practical considerations that happen to matter in that context. For example, If I were approached on the street by someone claiming to have a new medical product that cured some disease I knew science was struggling to cure, I might have normal incredulity towards their claim because of the set of probabilistic judgements I have acquired about human life and the world which enable me to reliably navigate practical concerns.Philosophical scepticism is not so concerned with practical knowledge but more about abstract knowledge. It is less concerned with discovering if we can judge things that affect practical life and more with whether we can hold any knowledge at all regardless of its significance for human life. For example, in the case of normal incredulity about the street medicine vendor, a set of more abstract assumptions were being made on which even posing that normal doubt depended on a more basic level, such as that I have a body and even that I exist at all. Philosophical sceptics typically think that certain knowledge of such basic epistemological claims is impossible or at least not currently warranted by the available evidence. For example, I could be a brain in a vat being manipulated by scientists to have the perceptual experiences of walking down the street and being approached by the street vendor. Normal incredulity is a secondary derivative concern which is dependent on knowing that I have a body and veridical experiences, which philosophical scepticism casts doubt on.The role/function of philosophical scepticism within epistemologySome Philosophers view philosophical scepticism as a theory which holds that knowledge is either impossible or currently unwarranted by the available evidence, but most view it as a challenge or difficulty to be overcome. ‘The sceptic’ is seen as a useful imaginary debating partner to consult after making epistemological claims, to see if they can defeat the sceptic. This tool is reminiscent of the Socratic dialogues in Plato’s writings where philosophy was seen to emerge from conversation and argument. The sceptic typically questions the adequacy of the justification for supposed knowledge. If the justification is that we can perceive what we claim to know, the sceptic would point out that we might be a brain in a vat with no veridical perceptions and so that justification fails. The distinction between local and global scepticism and the (possible) global application of philosophical scepticismLocal scepticism is scepticism about a particular claim (e.g. a particular sense experience) or domain of claims (e.g. all sense experience). Local scepticism occurs when our reasons for doubting are the sort which apply to specific knowledge claims.Global scepticism results from the reasons for doubt apply not to specific knowledge claims but seem to undermine all possible knowledge claims, e.g. the brain in the vat where scientists could manipulate our reasoning about mathematical concepts and our perceptual experiences both of the external world and our own mind.A contemporary global scepticism argument is Nick Bostrom’s simulation argument.P1: Minds can be simulated on computers.P2: Once a civilisation gains the technology to do so, it will simulate minds on computers which have conscious experiences indistinguishable from our own.P3: This will occur multiple times such that the number of simulated worlds will vastly outnumber the number of real worlds (one).C1: we should expect as a matter of probability to be in one of the simulated worlds.The strength of the simulation argument over the dreaming argument or the brain in the vat hypothesis is that it’s not simply a very difficult possibility to rule out but is actually overwhelmingly probable.Descartes’ sceptical arguments (the three waves of doubt)Descartes thought that he could find certain knowledge, which he defined as knowledge which cannot be doubted, if he progressively applied his method of doubt to areas of supposed knowledge.Step 1: The 1st wave of doubt is the argument from illusion. Descartes doubts his perception since it has gone wrong in the past, e.g sticks in water look bent. However, Descartes does not think this subjects all perceptions to doubt, only those special cases.The 2nd wave of doubt is the argument from dreaming. This casts doubt on all my current perceptions by claiming that I could be dreaming, in which case my perceptions might not be of reality and therefore cannot provide certain knowledge.Step 2: There are reliable criteria for telling the difference between waking and sleeping, such as the greater coherence of your perceptions when awake.Step 3: Descartes is only trying to cast doubt on your current perceptions, however.Step 4: Nonetheless this seems to leave knowledge of previous perceptions undoubted.Step 5: While the origin of previous perceptions can be reliably ascertained by coherence, it is arguably impossible to do this beyond any doubt as reliability is insufficient for certainty.Step 1: The 3rd wave of doubt casts doubt on mathematics, which Descartes claims withstands the dreaming argument. Descartes postulates that instead of a God there could be an evil demon deceiving you about supposed mathematical truths, so even they cannot be certain knowledge.Step 2: We could reject the concept of an evil demon as incoherent as it requires some kind of supernatural magic power which cannot be analysed sufficiently for us to even know whether it amounts to a logical possibility. Step 3: The brain in a vat scenario supposes that your brain is not in your body but is being manipulated by scientists to generate your conscious experiences. If that were the case you would never know. This is similar to the evil demon argument but more conceptually analysable and can therefore be more easily said to be a logical possibility which seems to have the same outcome as Descartes’ third wave of doubt, as the scientists could manipulate our brains to think that 1+1=3 when really it is 5.Step 4: However, arguably it is not possible to manipulate someone’s brain to think that 1+1=3. They could be manipulated into saying it, but it’s inconceivable that they could be manipulated into thinking it. The Incoherence of being deceived about logical or mathematical truths by scientists shows further that the evil demon relied on incoherent magical powers. It’s possible to define the evil demon as that which has the ability to deceive us about maths, but that presupposes the logical possibility of such a deception. This suggests a fault in Descartes’ conception of knowledge as that which we cannot doubt. Such a view depends on conceivability entailing possibility as it requires that our ability to doubt something matches whether it can be the case in reality.Descartes’ own response to scepticism: The Cogito.Step 1: After the three waves of doubt, Descartes’ applied his method of doubt to the question of whether he can know he exists. He claimed that doubting your own existence is incoherent since you have to exist in order to do the doubting. It is therefore impossible to doubt your own existence and so we can know that we exist.Step 2: Kierkegaard argued that Descartes’ argument was really a tautology as it assumed the conclusion it was trying to prove; (‘I’ think, therefore ‘I’ am), is little more than (‘I’ therefore ‘I’). Nietzsche also criticised Descartes, arguing that the cogito assumes that it is ‘I’ who thinks, that something has to exist in order to think, that thinking exists in causal relations, that what is happening really is thinking and not something else such as willing or feeling. Step 3: Some Modern scholars have interpreted Descartes’ Cogito as not intended to be an explicitly logical argument which predicates existence to a thinking subject, but more an observation that ‘something’ is happening in conscious awareness which presupposes existence.Empiricist responses to scepticism (Locke, Berkeley and Russell)reliabilism ................
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