Philosophy AS - epistemology

1. Perception
1. What is perception?
  1. (DR) Direct realist
    1. (IR) Indirect realist
      1. Indirect realism claims that we perceive physical objects which are mind-independent, but we do so via, or in virtue of, perceiving mind-dependent sense-data that are caused by and represent physical objects.
        We perceive sense-data immediately, and physical objects indirectly.
        John Locke - primary (PQ) and secondary qualities (SQ)
        (SQ) Secondary qualities exist due to sense-data being perceived to 'produce various sensations in us by their primary qualities.’.
        Clolour, temperature, taste etc
        (PQ) Primary qualities are the properties an object holds mind -independently of perception, qualities that exist despite our presence. A primary quality exists irrespective of any changes made - the primary qualities hold these properties ‘in and of itself’.
        extension, motion - including rest, solidity etc.
        ‘The tepid bowl’ - water has one temp (M-I,PQ) but heats (SQ) the perception of heat is M-D. Our senses perceive SQ, they’re M-D. PQ (eg extension) exists in an of itself, it’s M-I.
        Russell - IR sense-data and perception
        Russell argues from an epistemological stance of indirect realism; perception is achieved indirectly through mind-dependent sense data. (This stands in opposition to the view of direct realism: we perceive objects directly).
        1. We have variations in our perception.
        2. Our perception varies without corresponding changes in the physical object we perceive. (eg the desk remains rectangular, even if the way it appears to me changes as I look at it from different angles.)
        3. Therefore, the properties physical objects have, and the properties they appear to have, are not identical.
        4. Therefore, what we are immediately aware of in perception is not exactly the same as what exists independently of our minds.
        5. Therefore, we don’t perceive objects directly.
        Issues:
        1) leads to scepticism about the nature of the external world
        IR argues that a mind independent world causes mind dependent sense data (e.g. PQ/SQ). But sense data differs from perceiver to perceiver. So, who's right about the nature of the MI world? Well, the skeptic argues no one is right: we cannot know what the world is like, I can only know my sense data.
        2) leads to scepticism about the existence of the external world
        can we ever know the source of sense data? How can I prove an object and it's properties really caused my perception? Every attempt will just be more sense data, never it's supposed source.
      2. Berkeley - idealism
        If one were to apply Locke’s arguments against the mind independence of the SQ to PQ, one would be a Berkeleian idealist.
        1. ‘The Master Argument’: Nothing can exist unperceived, esse is percipi. (A tree for example, one cannot imagine a tree without it being perceived - because wherever we imagine a tree we imagine it from the point of view from some perceived. It is impossible to imagine a tree from no perceiver's point of view.)
        2. God perceives all.
        Rejecting Idealism:
        God's role in perception is questionable.
        The claim that everything I perceive is mind dependent leads to the conclusion that all that exists is my own experience. It gives me no reason to believe that anything other than my own mind exists, as all I perceive are Ideas.
        Solopsism
    2. All objects of perception are M-I and are perceived directly; it obeys Ockam's razor.
      1. (eg the reason I see the sky to be blue is because the sky possesses the property ‘blue’ which causes my perception to have the same property.)
        Arguments against DR:
        1) Russell's perceptual variation
        2) Argument from illusion
        (The crooked oar.) Rather than directly perceiving the stick, which would entail our seeing it as it truly is, we must instead perceive it indirectly, by way of an image or "sense-datum".
        This mental representation does not tell us anything about the stick's true properties, which remain inaccessible to us. With this being the case, however, how can we be said to be certain of the stick's initial straightness?
        If all we perceive is sense-data then the stick's apparent initial straightness is just as likely to be false as its half-submerged bent appearance. Therefore, the argument runs, we can never gain any knowledge about the stick, as we only ever perceive a sense-datum, and not the stick itself.
        3) Argument from Hallucination
        1. We perceive something as having a property.; we perceive this property so there must be a physical object that has this property.
        2. In a hallucination, we do not perceive a physical object at all.
        3. Therefore, what we perceive exists only in the mind- sense data.
        4. So, we perceive sense data in both hallucinations and veridical perception.
        5. Therefore, we only ever perceive sense data immediately- not the physical objects.
        6. Therefore, direct realism is false. We cannot distinguish between empirical reality and hallucination.
        3) Time-lag
        1. Visible light from our sun bounces off objects of perception and strikes our retina, this is human perception as DR understand it.
        2. Light from the sun is delayed by aprox 8 minutes.
        3. Therefore we do not percieve the light immediatly.
        4. Therefore, we do not percieve objects directly.
  2. I. Perception
    1. II. Knowledge
      1. Justified True Belief
        There are three components to the traditional (“tripartite”) analysis of knowledge. According to this analysis, justified, true belief is necessary and sufficient for knowledge.
        The Tripartite Analysis of Knowledge:
        S knows that p iff
        i. p is true;
        ii. S believes that p;
        iii. S is justified in believing that p.
        But is it always sufficiant for knowledge ?
        Edmund Gettier - 'a Gettier case'
        Where one has JTB but fails to have knowledge
        Case study one:
        The case’s protagonist is Smith. He and Jones have applied for a particular job. But Smith has been told by the company president that Jones will win the job.
        Smith combines that testimony with his observational evidence of there being ten coins in Jones’s pocket. (He had counted them himself — an odd but imaginable circumstance.) And he proceeds to infer that whoever will get the job has ten coins in their pocket.
        Notice that Smith is not thereby guessing. On the contrary; his belief b enjoys a reasonable amount of justificatory support. There is the company president’s testimony; there is Smith’s observation of the coins in Jones’s pocket; and there is Smith’s proceeding to infer belief b carefully and sensibly from that other evidence. Belief b is thereby at least fairly well justified — supported by evidence which is good in a reasonably normal way. As it happens, too, belief b is true — although not in the way in which Smith was expecting it to be true. For it is Smith who will get the job, and Smith himself has ten coins in his pocket.
        These two facts combine to make his belief b true. Nevertheless, neither of those facts is something that, on its own, was known by Smith. Is his belief b therefore not knowledge? In other words, does Smith fail to know that the person who will get the job has ten coins in his pocket? Surely so (thought Gettier).
        It contains a belief which is true and justified — but which is not knowledge. And if that is an accurate reading of the case, then JTB is false. Case I would show that it is possible for a belief to be true and justified without being knowledge. Case I would have established that the combination of truth, belief, and justification does not entail the presence of knowledge. In that sense, a belief’s being true and justified would not be sufficient for its being knowledge.
        Rejecting Gettier:
        Virtue epistemology
        You know p is true if;
        p is true;
        s believes in p;
        and s's true belief is the result of them exercising their intellectual virtue.
        If you use your intellectual virtues to find knowledge then that knowledge is a cognitive achievement
        Sosa
        Invented virtue epistemology
        If you imagine an archer aiming at a target, it is like a person aiming to know something about the world
        AAA structure are both necessary and jointly sufficient for Knowledge
        1A. Accurate
        Do you hit the target? Do you have the right beliefs about the right thing? Is what you're thinking true?
        2A. Adroitness
        Did you aim and shoot well? Did you do it right - as an exercise of intellectual faculty? As the name suggests, did you use the right skill?
        3A. Aptness
        Did you form your conclusion from 1A and 2A? Or was it just fluke K (Gettier)? It is accurate due to your adroitness.
        This defeated Gettier as his 'cases' held only A1 and A2, was simply fluke Knowledge
        III. The origins of knowledge and concepts
        Knowledge
        Synthetic
        A synthetic proposition is one that is not analytic, i.e. it is true not in virtue of the meanings of the words, but in virtue of the way the world is
        Analytic
        An analytic proposition is true or false in virtue of the meanings of the words
        A priori
        knowledge that does not require (sense) experience to be known to be true
        Relations of ideas
        a proposition which is mathematical or logical. It is rationally certain but tells us nothing about reality
        A posteriori
        knowledge that requires (sense) experience to be known to be true
        Matters of fact
        a proposition which is empirically verifiable. It tells us about the real world.
        Is all a priori knowledge knowledge of analytic propositions? Are all synthetic propositions known a posteriori?
        Rationalism
        NO
        we can have a priori knowledge of synthetic propositions E.g. through reason or innately.
        Empiricism
        YES
        if a proposition is not made true through logic or meaning; it can only be established by sense experience.
        Contingent and Necessary
        A truth represents a true statement whose negation must imply a contradiction in reality, such that the negation would be impossible
        A contingent truth, or falsehood, concerns something that could have been otherwise. A proposition that expresses a contingent truth can be rationally denied without resulting in any self-contradiction.
        See Diagram
        Infallibilism
        Instead of destroying JTB, it attempts to preserve it by improving the J.
        It does this by:
        s believes p;
        p is true;
        s is justified in believing p IFF s can't be mistaken, thus your J results in certainty.
        Flaws in infallibilism:
        1. It ends in very little knowledge
        To say you know something you have to be ultimately certain, which results in little 'knowledge'
        2. If you think you know something you also believe you are certian
        3. People want to say 'I know' but can't with this theory.
        So, humans want to be able to say they know something but this theory leave very little to know.
        4. Only super human epistemology works, as only superhuman knowledge (beings) can be certain.
        Reliabilism
        Reliabilism claims that you know that p if
        p is true;
        you believe that p;
        your belief is caused by a reliable cognitive process.
        Disadvantages: 1. Reliable methods can easily lead to falsehoods. (ie: 'I saw a dragon, therefore it's real')
        Advantage: of reliabilism is that it 1. allows young children and animals to have knowledge.
        2. It allows for knowledge to become broad in terms of how much we can be certain of knowledge
        2. Justification can often be explanatory, it destroys JTB by taking out the justification, but reliable methods don't always tell you why, how or when something works.
        3. You can just as easily believe a false proposition as a true one, due to the lack of certian justification

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