intuition and deduction

Question 1

Explain Descartes’ cogito as an example of an a priori intuition

Answer 1

• Descartes argued that all knowledge, if it is to be truly infallible, should be based on a priori intuitions (truths gained without further inference by the ‘natural light of reason’).
• One such intuition was the existence of himself, as he could not doubt the presence of his own doubt, thus his own thought, thus his being.
• The existence of his mind preceded any experiential conclusions or further truths, thus Descartes himself (who could conceive of his own self clearly {easily identifiable} and distinctly {easily separated}) could know ‘cogito ergo sum’ intuitively.

Question 2

Explain Descartes’ notion of ‘clear and distinct’ ideas

Answer 2

• Descartes argued that his obtainment of infallible knowledge should be based on intuited ideas that are both
• clear = vivid + immmediatly accessible to the mind, known with certainty cannot be doubted
• distinct = can be distinguished from other ideas, cannot be confused
• Examples include a mathematical + logiccal truths —> 2 + 2 = 4, descartes cogito, a priori truths in general
• The notion of clear and distinct ideas broadly corresponds with our understanding of analytic statements which are known a priori (without recourse to experience) and necessarily true (the opposite = logical contradiction)

Question 3

Explain how an empiricist might argue the cogito is not a priori knowledge

Answer 3

• Empiricists believe that all concepts and knowledge are obtained via experience (Hume’s copy principle and fork).
• Thus, Descartes’ belief that he has used reason to deduce the cogito goes against empiricist beliefs and is false
• His claim - that he exists on account of experiencing existence as a mind, which is to say thinking - is obviously not obtained prior to experience (or ‘a priori’).
• For this reason, Hume argues the concept of a self = meaningless. We are, for him, mere ‘bundles’ of experience with nothing connecting these together (i.e. no self).

Question 4

Explain Hume’s fork

Answer 4

• Hume claimed, with the proposal of a two-pronged ‘fork’, that for knowledge to count as meaningful it must be one of two things. Either
• a) a relation of ideas (a priori, analytic statements, which are necessarily true in all logically possible worlds, like 2+2=4)
• b) a matter of fact (a posteriori, synthetic statements, which are contingently true and experientially observable, like ‘grass is green’).
• Any knowledge claim which falls under neither category should be dismissed as meaningless speculation (‘consigned to the flames for containing nothing but sophistry and illusion’).

Question 5

Explain the meaning of ‘intuition’ and ‘deduction’ and the distinction between them

Answer 5

• Descartes defined intuition = information learnt a priori, without further inference, via ‘the natural light of reason’
• whereas deduction is the process by which further truths are obtained as valid conclusions from intuited true premises.
• An example would be the a priori intuition of the concept God (a being which contains all perfections) from which we can derive , ontologically God’s existence (since existence is a perfection - i.e. a non-existent God would be imperfect and thus logically contradictory).

Question 6

Outline Descartes’ proof of the external world

Answer 6

• I clearly and distinctly percieve a world of external physical pbjects
• 3 possible causes = our own mind, God, external physical objects themselves
• if cause = our own mind then our perceptual experiences would be voluntary but they are involuntary so cannot be our own mind
• if cause = God then our perceptual experiences would be deceptive but they cannot be deceptive as God exists (proved in d TM argument) and is all good ect and not a deciever so cannot be God
• therefore, cause of PE = external objects themselves
• therefore a world of external physical objects exists
• IF 12M THEN CIRCULARITY = ARGUMENT AGAINST

Question 7

Explain Descartes’ third ‘wave of doubt’

Answer 7

• The third wave is that from deception. Descartes concluded that if God does not exist then he could not be certain that within his own mind he was not being deceived.
• If an ‘evil demon’, say, was pulling strings and falsely placing knowledge there (such as ‘5’ in answer to 2+2) then Descartes not only cannot trust his sensory perception, he also cannot trust his a priori knowledge. = undermines all our knowledge claims
• we cannot know if we are being tricked —> our perceptions and experiences would be the same either way
• This argument leads to global scepticism (the ability to doubt all things)