the intuition and deduction thesis

Question 1

Descartes’ cogito

Answer 1

• I think therefore I am (cogito ergo sum)
• Descartes asks what he can know if he were being deceived by an evil demon
• I can’t doubt that I exist
• I am a thing that thinks and I can’t doubt this
• ‘i think’ is the first certainty
• I can doubt whether I have a body, so my existence doesn’t depend on whether or not I have a body
• the cogito is an example of a priori intution

Question 2

thinking

Answer 2

• what is classified as thinking: doubt, understand, affirm, deny, want, refuse, imagine, sense
• sense experience doesn’t depend on a body; eg i have sense experience in my dreams

Question 3

clear and distinct ideas (1/3) ~ rational intuition

Answer 3

• on the cogito: ‘in this first item of knowledge there is simply a clear and distinct perception of what I am asserting’
• while thinking it, i can’t doubt it
• if clarity and distinctness do not guarantee truth, then I can’t know that I exist
• i do know that I exist
• therefore, ‘as a general rule …whatever I perceive very clearly and distinctly is true’
• this is Descartes’ theory of rational intuition

Question 4

clear and distinct (2/3) ~ ideas

Answer 4

• an idea is clear ‘when it is present and accessible to the attentive mind - just as we say that we see something clearly when it is present to the eye’s gaze and stimulates it with a sufficient degree of strength and accessibility’
• an idea is distinct if it is clear and ‘it is so sharply separated from all other ideas that every part of it is clear’
• analogy with vision: truths revealed by the ‘natural light’

Question 5

clear and distinct ideas (3/3) ~ evil demon

Answer 5

• what guarantees that clear and distinct ideas true, even when the evil demon may exist
• to deny a clear and distinct idea is a ‘plain contradiction’
• the demon can not bring about contradictions
• clear and distinct ideas must be true (at the time one thinks them)
• thinking makes them true, eg ‘I think’
• we recognise their necessary truth

Question 6

Hume’s fork

Answer 6

• empiricist response to Descartes’ proof of the external world
• we can only know two types of claim: relations of ideas and matters of fact
• relations of ideas:
  discovered purely by thinking (so a priori)
  intuitively or demonstratively certain, based on contradiction and deduction
  empiricists claim that analytic truths are what counts
• matters of fact
  about what exists and is the case
  requires sense experience (a posteriori)
• analytic truths can’t be denied without contradiction since there is no possibility of it changing to be false since it doesn’t depend on anything which changes
• the intuition and deduction thesis uses a priori reasoning yet comes to a conclusion about matters of fact regarding the existence of an external world
• according to Hume’s fork, Descartes’ conclusion can’t be justifiably known from the premises
• intuitions of relations of ideas and deductions made about them therefore can’t be known about the world
• a priori intuition and deduction only provide us with analytic knowledge of the relations of ideas, not synthetic matters of fact

Question 7

a response to the cogito

Answer 7

• ‘I think’, is there an i and if so what does it mean
• if I exist, as a substance, from one thought to the next, Descartes has not shown this, only that ‘there are thoughts’
• if I exist as that which thinks this thought, Descartes has not shown I exist for more than one thought
• even if I know I exist, this isn’t rational intuition, but comes from my experience of my mind
• Descartes’ response: claims it is clear and distinct that thoughts require a thinker

Question 8

what is the trademark argument

Answer 8

• Descartes claims that our concept of god is innate
• he uses our concept of gold to argue that it is proof that god exists
• god implanted the idea of himself in us like a trademark

Question 9

Cartesian metaphysics

Answer 9

• substance: ‘stuff’ that can exist independently, eg mind and physical matter (more real)
• attributes: properties of substances, eg colour, shape, thoughts
• modes: ways that properties can be, eg walking, ways of thinking (less real)

Question 10

trademark argument

Answer 10

1. I have a concept of god
2. the concept of god is infinite and perfect
3. my mind is finite
4. the cause of the concept must have as much reality as the concept itself
5. therefore, my mind can’t be the cause of the concept
6. the only possible cause of the concept is god
7. therefore, god exists

Question 11

objections to the trademark argument

Answer 11

• from an empiricist pov
• Hume claims that we can create the idea of god by taking ideas about ourselves and expanding them, eg good, intelligent
• response: Descartes claims that we can’t understand notions like imperfection without something perfect to compare them to
• Hume claims that we do not know that everything needs a cause, so the concept of god may not have a cause
• eg you can’t understand the concept of apples through the absence of apples but you can understand the concept of no apples when there is apples
• response: does it make sense to say that something might come from nothing

Question 12

cosmological argument

Answer 12

1. I exist
2. either I am uncaused, I caused myself or I am caused by another
3. I am not uncaused (this makes no sense)
4. I did not cause myself (if I did, I would give myself all perfections)
5. therefore, I am caused by another
6. whatever caused me is the cause of its own existence or is caused by another
7. if it is caused by another, the point repeats
8. there can’t be an infinite sequence of causes
9. therefore, there is something which is the cause of its own existence (and is therefore perfect)
10. there is a god

Question 13

objections to the cosmological argument

Answer 13

• Hume claims that we do not know enough about causation
• can there be uncaused causes
• Hume says that we can imagine a brick coming into existence without a cause, so how do we know that is impossible
• response: imagining nothing followed by a brick is not the same as imagining a brick coming into existence uncaused
• can there be infinite sequences of causes
• response: if there were an infinite series of causes preceding the presence, then we would not be here, you can’t get to the end of an infinite series

Question 14

doubt in mediations

Answer 14

• doubt 1: our senses are unreliable
• doubt 2: I might be dreaming
• doubt 3: the evil demon

Question 15

certainty in meditations

Answer 15

• knowledge one: the cogito
• knowledge two: the clear and distinct rule (anything perceived that is clear and distinct is true)
• knowledge three: god exists
• knowledge four: god would not deceive (because he is perfect)
• knowledge five: I can trust my faculties (because god created us)

Question 16

ontological argument

Answer 16

1. God is the being with all perfections
2. existence is a perfection
3. therefore, god exists

Question 17

objections to the ontological argument

Answer 17

• Hume claims that existence can’t be part of the definition of god since ‘god does not exist’ is not a contradiction
• response: maybe we can see that it is once we fully understand the concept of god
• Kant says that existence was not a property, it does not add to our understanding of something

Question 18

the concept of physical object

Answer 18

• when a piece of wax melts, it loses all its sensory qualities (eg shapes, smell)
• yet I believe it is the same wax
• therefore, what I think of as the wax is not its sensory qualities
• what i think is the wax is what remains through the changes of its sensory qualities
• this is a body, something that is extended
• ie it has the size and shape and takes up space and changeable, it’s sensory and spatial properties can change
• i know that the wax a can undergo far more possible changes, including changes in its extension, than I can imagine
• therefore, my concept of the wax as extended and changeable does not derive from my imagination (and therefore it does not derive from perceptual experiences)
• therefore, i comprehend the wax as what it is (as opposed to its sensory qualities) by my mind alone
• only this thought of the wax, and not the perceptual experience of it, is clear and distinct

Question 19

physical objects are possible

Answer 19

• Descartes says that they could exist, not that they actually exist as he is an indirect realist
• meditation II: our clear and distinct idea of material objects is that they are extended
• meditation V: we can know that clear and distinct ideas are true so material objects really are extended, if they exist at all
• meditation VI: the only reason for thinking that god can’t make something is that the concept of it is contradictory; the concept of a physical object is not contradictory; so if god exists, it is possible that physical objects exist

Question 20

god is not a deceiver

Answer 20

• we know god exists and is perfect from earlier proofs
• deception is an imperfection
• being deceived is bad (loss of truth)
• causing something bad is wrong
• god is perfect and therefore can not do something wrong
• god ‘has permitted no falsity on my opinion which he has not also given me some faculty capable of correcting’
• if we work with clear and distinct ideas and do all we can to avoid error, we won’t go wrong

Question 21

the proof

Answer 21

• i have involuntary perceptual experience of physical objects
• if the cause of my perceptual experiences is my own mind, my perceptual experiences are voluntary
• because i know my mind, i would know if my perceptual experiences are voluntary
• therefore, because I know that my perceptual experiences are involuntary, i know that the cause of my perceptual experiences is not my own mind
• therefore, the cause must be some substance outside me, either god or physical objects
• if the cause is god, then god has created me with a very strong tendency to have a false belief (that physical objects exist) that I can’t correct (this is challenging Berkeley)
• if god has created me with such a tendency, then god is a deceiver
• but god is not a deceiver, so god did not create me with a tendency to falsely believe that physical objects exist
• therefore, if god exists, the cause of my perceptual experiences of physical objects is the existence of physical objects
• god exists
• therefore, there is an external world of physical objects that causes our perceptual experiences

Question 22

the proof simplified

Answer 22

• the cause of perception is Descartes’ own mind, god or another mind, or physical objects
• not Descartes: he is not dreaming
• he can tell the difference between imagination and experience
• not god or another mind as otherwise god is a deceiver
• therefore, the only option is that perception is caused by a world of physical objects

Question 23

knowledge of the external world

Answer 23

• humans make errors when they rely solely on sense experience or reason incorrectly with it
• the purpose of sense experience is to help us find beneficial things (eg air, food) and avoid harmful things (eg fire, thorns)
• if we use sense experience responsibly in combination with reason, we will not make errors

Question 24

empiricist alternatives to the proof

Answer 24

• Descartes’ argument relies on a number of controversial steps: cogito, existence of god, clear and distinct ideas - all of these can be challenged
• alternative 1: Russell and Locke give inductive arguments for the existence of the external world (the best hypothesis is that there is an external world)
• alternative 2: Berkeley claims that our concept of physical objects is incoherent so we should only belive in ideas

Question 25

intuition and deduction are

Answer 25

• a priori methods of gaining knowledge
• Descartes thinks we can gain synthetic knowledge through a priori means by intuition and deduction

Question 26

intuition

Answer 26

the ability to know something is true just by thinking about it

Question 27

deduction

Answer 27

a method of deriving true propositions from other true propositions (using reason)

Question 28

Descartes’ notion of clear and distinct ideas

Answer 28

• the cogito is a clear and distinct idea
• a clear idea is ‘present and accessible to the attentive mind’
• an idea is distinct when it is so sharply separated from all other ideas that every part of it is clear
• Descartes claims that since the Cogito is a clear and distinct idea which he knows to be true, then clarity and distinctness must ‘as a general rule’ be a sign of truth

Question 29

empiricist categories of knowledge

Answer 29

• knowledge from experience: contingent, synthetic, a posteriori
• relations among ideas: necessary, analytic, a priori

Question 30

rationalist categories of knowledge

Answer 30

• accept the categories empiricists accept, but also believe that a priori, synthetic knowledge is possible

NB: can accept innate knowledge through intuition and deduction

Question 31

rationalist and empiricist categories of knowledge

Answer 31

• empiricism says all a priori knowledge is of analytic truths (i.e. there is no synthetic a priori knowledge)
• rationalism says not all a priori knowledge is of analytic truths (i.e. there is at least one synthetic truth that can be known a priori using intuition and deduction)