Reason as a source of knowledge

Reason as a source of knowledge

1. Innatism

   • Plato
     • Paradox - 1) If we know something then there is no need to learn it. 2) If we don't know something then we don't know we have to learn it. 3) Therefore this is a paradox - we can never learn anything
       • Plato solves this by saying that learning is simply a form of remembering.
     • Meno's slave boy - Socrates gets the dumbest person around to double the area of a square. But he does it wrong and gives up. Socrates then gives him a diagram and asks him questions that help him double the area of a square. He says this shows how knowledge is innate within us and we just need to remember it.
   • Liebniz
     • Said that our senses reveal contingent truths to us, not necessary ones. We can see that a square has four sides, but we have not seen every square, so we cannot know that all squares have four sides. Our senses are not sufficient for explaining necessary truths, so they are only sufficiently explained by experience and innate concepts that we uncover.
     • Necessary - it must be th case as it relies on nothing else to be true. In terms of knowledge, necessary truths are things that must be true regardless of anything else.
     • Contingent - it could be the case, but doesn't have to be (as it depends on something else). In terms of knowledge, it means x is true but only because of y.
     • Marble block - we chip away at it to uncover necessary truths.
   • Citiques - Locke
     • All ideas can be explained by previous sensations that we have had.
     • If you have an idea, then you know you have an idea. the concept that you know something without being conscious of it is absurd.
     • If knowledge is innate then it must be part of all human minds. 1) If there is innate knowledge, it is universal. 2) For an idea to be part of the mind, the mind must be aware of that idea. 3) Therefore, innate knowledge is knowledge that every human being is aware of. 4) Children and idiots do not know geometry, or facts like 'it is impossible for the same thing to be and not to be' as they don't understand them. 5) following the above, there are in fact no universal claims that are accepted by even children and idiots. 6) Therefore, there is no innate knowledge.

2. Empiricism - Locke

   • Tabula Rasa
   • Simple ideas - ideas are single, intrinsic and do not refer to anything else e.g. the colour blue, the feeling of cold, the sound of a musical note etc.
   • Complex ideas - ideas made up of multiple simple ideas e.g. a block of ice is blue, cold, hard etc. all at once.
   • First distinguishes between sensations and ideas. Sensations are our immediate experiences of the external world whereas ideas are the thoughts, memories, concepts etc. in our mind.
   • Telling the difference between simple and complex ideas.
     • Simple ideas are phenomenally simple or 'uncompounded, such as shades of colour and tastes. They cannot be analysed in terms of other concepts whereas complex concepts can be broken down.
     • Simple ideas are copies of reality (Locke), but complex concepts need not be a copy of anything that exists.
     • Simple ideas always represent the intended object fully
     • Words standing for simple ideas are less likely to be misapplied e.g. it would be odd to apply the word 'red' to the idea 'green' accidentally.

3. Empiricism - Hume

   • Arguments against innatism
     • If someone is unable to perceive certain impressions - they are unable to obtain any associated ideas. E.g. a blind person who has never seen colour will not have the idea of blue. This goes against the statement that all knowledge is innate.
     • Because all ideas are copied from impressions (the copy principle), this applies to internal impressions too. e.g. you can't have the idea of love until you've experienced it too.
   • Hume's Fork
     • Matters of fact
       • A posteriori
       • Contingent
       • Synthetic
       • Can be contradicted and still make sense
     • Relations of ideas
       • A priori
       • Necessary
       • Analytic
       • Tautologies and therefore cannot be contradicted
   • Says we can have a priori knowledge, which Locke rejected, but he says it is trivial, as it doesn't tell us anything of importance.
   • Anything that doesn't fit on the fork can't be knowledge.

4. Intuition and deduction thesis - Descartes (and Hume's responses)

   • A deduction is a form of reasoning where you can be certain of a conclusion based on your premises.
   • the existence of his mind is the one thing that he cannot doubt. Cogito Ergo Sum.
     • Hume says that we do not experience a mind, but rather a series of one thought followed by another thought. He points out that we never experience a single mind, we reflect upon each thought but not on all thoughts at once.
   • C+D ideas. 1) In this first item of knowledge (the cogito) there is simply a clear and distinct perception of what I am asserting, 2) If clarity and distinction do not guarantee truth, then I cannot know that I exist. 3) I do know that I exist. 4) Therefore, as a general rule, whatever I perceive clearly and distinctly is true.
     • CLEAR - when we are able to think about an idea fully with all the attention of our mind.
       • DISTINCT - if the idea is clear and it is not defined in terms of anything else.
     • COUNTER - these are just like Hume's relations of ideas, and he calls them trivial, due to the fact that we get the ideas originally from experience, then just use rationality to realise they mean the same thing and tell us nothing new about the world, while Descartes holds them as the utmost importance due to the fact that they are the only things he can be certain of.
   • God/The Trademark Argument
     • 1. The cause of anything must be at least equal to its effect (CAP). 2) My ideas must be caused by something. 3) I am an imperfect being. 4) I have an idea of God, which is a supremely perfect being (SPB). 5) Therefore, I can't be the cause of my idea of God. 6) Only a perfect being can be the cause of my idea of God. 7) Therefore, God must exist.
     • COUNTER - Refute the CAP
     • COUNTER - Hume's fork: we only become aware of cause and effect through experience, and the only way to know about the cause of anything is by observing it in conjunction with its effect. As we have never experienced the cause of our idea of God, we cannot assume it is God himself.
     • COUNTER - Hume says that we don't even have an idea of an SPB at all, God is just a being with all the attributes of a human, but 'extending beyond all limits'. But as Hume says we don't have the idea of 'infinite', only 'not-finite'. In this way we are able to explain God as a complex idea made up of qualities that we have just adapted from experience of humans.
   • The External World
     • The Wax Example (substance)
       • Shows how the concept of wax is not understood from its qualities. In fact, I know that wax can change into all sorts of forms, therefore, whatever wax is, as a substance, I know in my mind alone, not from my perceptions of the object.
       • COUNTER - As with the mind, Hume says that we do not perceive one continuous substance, but one, then another, then another as we look in different directions.
     • God and the External World
       • Because God is not a deceiver, thenhe would not allow incorrih=gible errors, but would give the ability to form true beliefs and so he Descartes can dismiss the possibility of the evil demon - if one were deceiving him he would have no way of correcting his beliefs about the world. Among these beliefs is that physical objects exist and are extended in space. Because God can bring about anything that corresponds to a C+D idea, and Is not a deceiver, he can know that there are such physical objects.
       • COUNTER - The argument falls apart because we have dissected Descartes' argument fo the existence of God.
       • COUNTER - Basing any truths about the world on the existence of a being which Descartes can't demonstrate and is therefore imagining crosses the fork.

5. Critiques of Empiricism

   • The missing shade of blue - If a man had seen every shade of blue apart from one, then most would say that the man could formulate the idea of the missing shade, which is problematic form him as this simple idea has no impression from which it came.
     • Hume brought this up, but then said it was too singular to have much importance.
     • COUNTER - The missing shade is a complex idea, as it is a combination of different ideas of colour
     • COUNTER - You don't really have an idea of the missing shade, just the concept.
   • There are many concepts that seem to be different from Hume's interpretation of an idea, like justice, truth or beauty.
   • It is difficult to see how language derives from impressions. When I say 'red' this is not the same as having the impression of red. So does this mean that the word 'red' must derive from a different impression than having the experience of red?
     • Chomsky argued that language must in part derive from innate grammar rules.