Knowledge empiricism

Knowledge empiricism

1. Definitons

   • a priori - logic and reasoning eg: all bachelors are unmarried
   • a posteriori - logic through sense experience eg: there are 7 billion people in the world
   • analytic statements - true or false by definition eg: triangles have 3 sides
   • synthetic statements - NOT true by definition (they need evidence to back it up eg: ripe tomatoes are red

2. a priori/a posteriori is how we check or establish knowledge

   • a priori concepts are not derived from experience and a posteriori ones are

3. Empiricism vs rationalism

   • many have assumed that only analytic propositions are known a priori and all synthetic proposition are known a posteriori
   • 'Bachelors are unmarried' is not only known a priori but is also analytic. 'you are reading this book' is synthetic and can only be known through sense experience so is a priori
   • But does it always happen this way?
     • all analytic statements are known a priori because they are true or false by definition, and we don't need empirical evidence
       • Are all propositions that are known a priori analytic?
         • Could we have a priori knowledge of some analytic statements
     • empiricists claim that all knowledge of synthetic statements is a posteriori and all a priori knowledge is of anything proposition. So anything we do not know through reason and logic alone must be tested by the senses (NO,WE CAN'T)
       • Rationalists deny this, they claim that there is some a priori knowledge of synthetic propositions, either because that knowledge is innate or because we can gain such knowledge through reason, rather than sense experience (YES)

4. Hume

   • An essay concerning Human understanding
   • Hume's fork
     • Hume defend knowledge empiricism, arguing we can have knowledge of just two sorts of claims: the relations between ideas and matters of fact
       • Relations of ideas
         • 1. Relations of ideas 'can be discovered purely by thinking, with no need to attend to anything that actually exists anywhere in the universe'. Matters of fact, by contrast are 'propositions about what exists and what is the case
           • 2. Relations of ideas are statements that are 'either intuitively or demonstratively certain' Hume gives eg: 5*3=30/2 as a statement about the relations of numbers. Relations of ideas that are demonstratively certain are known by deduction. (matters of facts are not known by deduction, because they are statements that can be denied without any contradiction). But any claim that can be shown to be false by deduction implies a contradiction
       • Matters of fact
         • Hume argues that matters of fact are the basis of knowledge as they are what we experience
         • All knowledge that goes beyond what is present to our senses or memory rests on casual inference
           • eg: I receive a letter from a friend with a French postmark on it, and I believe that my friend is in France because I infer from the post mark to a place
             • however, you cannot work out what effects an object will have when you never have experienced it before
               • eg: by examining bread, you do not know that it will not nourish tigers
                 • only experience enables us to infer causes from effects. We cannot discover real truths through experience alone

5. Arguments against

   • Empiricists deny that there is any a priori knowledge of synthetic propositions. The only knowledge that we have is either (1. a priori knowledge of analytic propositions and what can be deduced from them) or (2. a posteriori knowledge of synthetic propositions)
     • any claim that is either analytic not known a posteriori, we don't know
       • we may object that this rules out many claims that we think we know, for example 1. According to empiricism, all knowledge of synthetic propositions is a posteriori 2. physical objects exist is a synthetic proposition 3. but we cannot know, through sense experience, what physical objects exist 4. therefore, according to empiricism we cannot know that physical objects exist 5. therefore, either we cannot know that physical objects exists or empiricism is fake 6. but we can know that physical objects exist 7. therefore, empiricism is false

6. Descartes meditations 1

   • Descartes provides an argument
     • he says that he has been deceived by his senses in the past eg: looked at paper but didn't know is he was seeing or dreaming it
       • we can object that there are reliable ways or distinguishing waking perception from dreaming, such as far great coherence of perception
         • Descartes says that we can be imagining even is we are awake
           • this argument can be used to object to empiricism in other ways eg: we could only know that God exists from sense experience
             • But can we? Hume argues that we can't

7. Intuition and deduction thesis

   • Rationalists claim that we have knowledge of synthetic propositions that does not depend on sense experience
     • they argue that there are two ways in whish we find such knowledge
       • A) we have a form of rational intuition or insight an the power of deduction with together enables us to grasp certain truths intellectually
         • B) we know certain truths innately
           • gut feeling refers to a rational intuition. Such as in a deductive argument when you trust that if the premises are true the conclusion must also be true. This is a rational process and at the heart of rational intuition we have the concept of discovering the truth or a claim just by thinking bout it

8. Does Descartes know what he claims to know?

   • If Descartes has failed too prove the tree main claims existence of the self, God and physical objects, then he has not shown we have knowledge through a priori reasoning
   • There are several objections
     • Does he really prove that he is a thinking thing? If he does manage this then is it really a priori knowledge It can be said to derive from our experience of ourelves.
       • Many object of how he proves God and his argument on the existence of physical objects relies on the existence of God

9. Cartesian circle - his argument is circular

   • I a certain that God exists only because I am certain of whatever I clearly and distinctly perceive and yet I am certain of whatever I clearly and distinctly perceive only because I am certain that God exsists
     • Lacewing says this is possibly a misinterpretation of Descartes - his argument does seem to suggest you can be certain of what you perceive without relying on food