the intuition and deduction thesis Flashcards
1
Q
Descartes’ cogito
A
- 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
2
Q
thinking
A
- 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
3
Q
clear and distinct ideas (1/3) ~ rational intuition
A
- 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
4
Q
clear and distinct (2/3) ~ ideas
A
- 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’
5
Q
clear and distinct ideas (3/3) ~ evil demon
A
- 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
6
Q
Hume’s fork
A
- 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
7
Q
a response to the cogito
A
- ‘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
8
Q
what is the trademark argument
A
- 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
9
Q
Cartesian metaphysics
A
- 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)
10
Q
trademark argument
A
- I have a concept of god
- the concept of god is infinite and perfect
- my mind is finite
- the cause of the concept must have as much reality as the concept itself
- therefore, my mind can’t be the cause of the concept
- the only possible cause of the concept is god
- therefore, god exists
11
Q
objections to the trademark argument
A
- 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
12
Q
cosmological argument
A
- I exist
- either I am uncaused, I caused myself or I am caused by another
- I am not uncaused (this makes no sense)
- I did not cause myself (if I did, I would give myself all perfections)
- therefore, I am caused by another
- whatever caused me is the cause of its own existence or is caused by another
- if it is caused by another, the point repeats
- there can’t be an infinite sequence of causes
- therefore, there is something which is the cause of its own existence (and is therefore perfect)
- there is a god
13
Q
objections to the cosmological argument
A
- 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
14
Q
doubt in mediations
A
- doubt 1: our senses are unreliable
- doubt 2: I might be dreaming
- doubt 3: the evil demon
15
Q
certainty in meditations
A
- 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)
16
Q
ontological argument
A
- God is the being with all perfections
- existence is a perfection
- therefore, god exists
17
Q
objections to the ontological argument
A
- 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
18
Q
the concept of physical object
A
- 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
19
Q
physical objects are possible
A
- 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
20
Q
god is not a deceiver
A
- 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
21
Q
the proof
A
- 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
22
Q
the proof simplified
A
- 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
23
Q
knowledge of the external world
A
- 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
24
Q
empiricist alternatives to the proof
A
- 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
25
Q
intuition and deduction are
A
- a priori methods of gaining knowledge
- Descartes thinks we can gain synthetic knowledge through a priori means by intuition and deduction
26
Q
intuition
A
the ability to know something is true just by thinking about it
27
Q
deduction
A
a method of deriving true propositions from other true propositions (using reason)
28
Q
Descartes’ notion of clear and distinct ideas
A
- 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
29
Q
empiricist categories of knowledge
A
- knowledge from experience: contingent, synthetic, a posteriori
- relations among ideas: necessary, analytic, a priori
30
Q
rationalist categories of knowledge
A
- accept the categories empiricists accept, but also believe that a priori, synthetic knowledge is possible
NB: can accept innate knowledge through intuition and deduction
31
Q
rationalist and empiricist categories of knowledge
A
- 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)
