descartes intuition an deduction thesis

analytic proposition

a proposition that is either true or false in virtue of the meaning of the words e.g a bachelor is an unmarried man

a priori

a proposition could be a priori if it doesnt require experience to know if its true or false

a posteriori

a proposition that requires knowledge to be known true or false

what do empiricists claim,

a priori knowledge is of analytic propositions and knowledge of synthetic propositions is known a posteriori

what do rationalist claim

a priori knowledge of synthetic propositions can be known true or false through rational insight and reasoning

what are synthetic propositions

a proposition that isn’t analytic and is true or false depending in the way the world is

what is the intuition and deduction thesis

a rationalist argument presented by descartes aiming to show that we can gain knowledge through rational intuition and deduction

what kind of arg is descartes rational intuition and deduction thesis

deductive - if the premises are true then the conclusion should also be true

when descartes is trying to establish how gain knowledge through rational intuition and deduction, what are the 3 things that he doubts

• his own existence

• god’s existence

• the existence of the external world

what are his three waves of doubt in order

• illusion

• dreaming

• evil demon

explain how descartes overcomes his first wave of doubt

• he realises that he cant doubt everything in the world as that would take too much time - since he starts to doubt the fundamental principles that his ‘knowledge is built upon’

• he first doubts his sensory experience as illusions prove that his sensory experience can deceive him

• since his sensory has deceived him before he feels that he cant be sure that it won’t do it again

• however through more reasoning, he comes to the conclusion that illusions are rare and unique occurrences and so arent good enough reason to doubt all of his sensory experience

• thus overcoming, his first wave of doubt

explain how descartes overcomes his second wave of doubt

• descartes then worries that all his perceptions are false as they could all be in a dream - this very problematic as if we are dreaming we would have no way of knowing that we are

• everything in dreams is false so we wouldn’t be able to distinguish between dreams and reality

• but through more thinking descartes concludes that dreams arent as coherent as reality

• and cements this when he thinks about how concepts such as size, quantity and time are constant even in dreams and so don’t give us reason to doubt

explain how descartes overcomes his last wave of doubt

• Descartes then worries that an evil demon is deceiving him and making him think that that the things he knows are true even though they arent

• this leads descartes to doubt everything even the fundamental ideas of maths, shape and science

• this leads descartes to scepticism and prompted him to find the foundation of knowledge beyond doubt

• leading descartes to establish himself as a thinking in his cogito

how does descartes come to his cogito

• after his waves of doubt descartes is in a position of extreme doubt but the only thing that he can be certain of is that he is a thinking thing

• it is this revelation of himself as a thinking that he uses to overcome the evil demon scenario - as something has to exist for the evil demon to deceive in the first place

• he also concludes that the fact that he can doubt his experience is proof of his existence

• leading him to the famous cogito ‘I think therefore I am’

• ‘I think’ is a synthetic proposition so Descartes has proven this synthetic truth ti be true by just rational intuition and deduction - so rationalism is correct

why are clear and distinct ideas important in descartes theory

because after reflecting in his cogito he realises that the certainty of cogito relies on how the idea presents itself to him in his mind. so he concludes that the cogito is as a result of a clear and distinct idea

define a clear idea

an idea that is accessible to the attentive mind

what is a distinct idea

one that is sharply distinct from all other ideas

what claim does descartes make about clear and distinct ideas

he says that they are indubitable