Perception as a source of knowledge Flashcards
1
Q
what is empiricism
A
our fundamental knowledge comes from the sense+experience
and all knowledge is known posteriori
2
Q
what is rationalism?
A
knowledge comes from reason
and all knowledge is known a priori
3
Q
what is a priori?
A
knowledge doesnt depend on expereince
4
Q
what is posteriori?
A
knowledge depends on expereince
5
Q
definition of perception
A
expereince using our 5 senses
6
Q
what is realism
(about the external world)
A
the view that the world outsid our minds is real.
we experience the world directly, unmediated by anything
7
Q
definition of direct realism (DR)
A
the qualities we experince in objects are possessed by the objects themselves
so, appearence and reality should be idientical
8
Q
what do realists claim
A
what we percieve are physical objects which exist independently of our minds
9
Q
what is sense experinece
A
awareness of physical objects through senses
10
Q
What is verdical perception
A
matching with reality
11
Q
strengths of naive DR
A
common sense, simplicity, Ockams razor
12
Q
what is Ockams razor
A
do not multiply entities beyond necessity
13
Q
criticism of DR
illusions
A
- objectively, the world can only be one way at one time
- DR says that we percieve the world directly
- if so, we percieve the world as it is- nothing ‘gets in the way’ to stop it appearing as it is
- illusions show that the world is not percieved as it is
McGurk effect- facial expression clashes with what we hear therefore creating an auditory illusion
14
Q
criticism of DR
perceptual variation
A
- what i see changes
- the object itself cant be supposed to change
- therefore what i see is not the object
Bertrand Russel’s table
properties physical objects have and the properties they appear to have are not always identical
15
Q
criticism of DR
time lag
A
- all perception is a process which takes time (e.g the sun)
- therfore we see things as they were in the past
- but the past no longer exists- it isnt reality
- so we cannot percieve reality directly
- so we must percieve something else e.g sense data
16
Q
criticism of DR
hallucinations
A
- some sense experinece is of hallucinations
- but in any experince something is being percieved
- therfore hallucinations dont exist in reality but in our heads
- hallucinations are perceptions of sense data
- some hallucinations are subjectively indistinguishable from verdical perceptions
- suggests all perception is sense data and not objects themselves
leads to indirect realism
17
Q
what is sense data
A
a mental image
18
Q
what is indirect realism (IDR)
A
we view the world through sense data, perception is indirect
we always directly perceve sense data
19
Q
IDR
what is the phenomenal principle
A
- i must be seeing somehting in order to have an experinece
- it must be something mental that i see, if its not reality
- therefore im not perceiving a mental image
20
Q
defintiion of subjectively indistinguishable
A
feels the same
21
Q
qualities of sense data
5 points
A
- mental- mind dependent
- private to each person
- therefore seeing them slightly differently
- subjective
- temporary (transient)
22
Q
qualities of physical objects
6 points
A
- material
- exists in the external world so mind-independent
- public to everyone
- an object in reality that possesses characteristics
- objective
- permanent
23
Q
what are primary qualities
A
qualities that physical objects themselves have
an object must have these qualities to exist
24
Q
examples of primary qualities
A
- mass
- solidity
- height
- density
- depth
- weight
- width
- figure
- mobility
Primary qualities are measureable
25
what are secondary qualities
qualities that are subjective
| dependent on the person perceiving them
26
examples of secondary qualities
* colour
* taste
* texture
* smell
* sound
| secondary qualities are not measurable
27
veil of perception criticism
| weaker version
1. if we only perceive sense data directly,how do we know what reality is like
28
response to veil of perception criticism (weaker version)
Primary+Secondary qualities:
1. we cna know we are experincing something so something exists in reality
2. we experince PQ via our sensedata
3. this resembles what the object is like in reality
4. so we can know about the nature of reality i.e. the PQ's of the object
| THIS IS LOCKE'S RESPONSE
29
veil of perception criticism
| stronger version
if we only percieve sense data directly, how do we know there is an external world causing this. We dont know the exdternal world exists
| leads to skeptism about the existence of mind independent objects
30
response to veil of perception criticism (stronger version)
| involuntary nature of perception
1. we have no choice over our perceptual experinces (unlike imagination)
2. if i write on paper, i cant not see it
3. this shows that there is a mind independent external world
31
response to veil of perception criticism (stronger version)
| coherence of the senses
1. our sense data is caused by mind-independent objects
2. locke's flame- if you see a bonfore, you shoukd be able to hear, feel it etc
Trotter-Cockburn develops this:
1. we learn which visual experinecs go with which auditory experinece e.g seeing a dog and hearing a dog bark
2. we know what sound it will make
32
issue with responses to veil of perception criticism (stronger version)
| involuntary nature of perception AND coherence of the senses
neither of these responses are decisive.
both of them could be explained by a demon, simulation etc
| these are weaker responses
33
response to veil of perception criticism (stronger version)
| best hypothesis
1. the external world exists because its a simple and powerful explanation of our perceptual experinces (sense data)
2. it is SIMPLE because it matches our instinctive belief in the existnec of the ext. world
3. it is powerful because it can say why we experince things as bahvaing in regular+predictable ways
| russell's cat -moves from one place to another - it exists
## Footnote
this is the strongest response
34
who's response is 'involuntary experinces'
Locke
35
who's response is 'coherence of the senses'
locke + trotter-cockburn
36
who's response is 'the best hypothesis'
Bertrand Russell
37
what does berkeley say about sense data to criticise it
| idealism
sense data and the ext. world are too different to give us knowledge
| so sense-data cannot represent the external world
38
ideas cant be like material objects
| explain.
1. all sense data, including those of so called PQ's, depend on the mind
2. therefore we requre a perceiving mind to exist
3. since matter is said to be unperceiving, it cant have such properties
39
what is the likeness principle
1. the idea that ideas (or sense data) can only resemble other ideas and therefore we can make no sense of the claim that our ideas could be like or resemble the primary qualities of objects
40
what does berkeley say about PQ'S and SQ's
both are perceiver dependent
41
berkeleys arg against locke
| size arg
1. size is supposed to be a primary quality
2. but it appears to vary from perceiveer to perceiver
3. so, size is perceiver dependent
42
berkeleys arg against locke
| dependency
1. perception of so-called PQ's, like shape, depends on perceiving something on perceiving SQ's like colour
2. we need colour to distinguish shapes visually, or else where are the edges
3. we need texture to distinguish shapes tactually
4. therefore, the so-called PQ's must also be perceiver dependnet
43
# how successful is Berkeleys PQ/SQ arg?
does the fcat that PQ are subject to perceptual variation show that there is no real difference between PQ and SQ?
NO- berkely is wrong. Our ideas of PQ can vary, but remember that the ideas are not the same thing as the qualites
44
# how successful is Berkeleys PQ/SQ arg?
does the fact that we cant access PQ except through SQ show that there is no real difference between them/
locke claimed that there were qualities objects had in themselves independent of us perceiving them- but if we can only perceive them through SQ, how can we know this? so is there really a distinction between PQ and SQ/
45
what is idealism
that the immediate objects of perception are physical objects, and all physical objects are mind dependent, so theres no external world
| an anti-realist theory
## Footnote
the eorld is mind-dependent, the physical world is composed of ideas not matter
46
the basics of idealism
| the world is physical, but mental not material
* we perceive physical objects directly
* but we only perceive ideas directly
* so physical objects are ideas (i.e sense data)
47
the basics of idealism
| why are all qualities ideas
* because all qualities are perceiver dependent
* no such thing as the PQ/SQ distinction
48
the basics of idealism
| the master arg. (simple)
* we cant even think of something existing unperceived (let alone experinence it)
* so there is no external world
49
what is sense data
| in realtion to idealism
1. sense data are the ideas that make up physical objects
2. more vivid than other ideas, they seem to be outside the mind- very real
3. no conscious control, sense data doesnt arrive or disappear because we will them too
50
what are concepts
| in realtion to idealism
1. concepts are the ideas that make up our thoughts e.g beliefs
2. less vivid than sense-experince
3. some conscious control, we can think of concepts when we want to
51
what are physical objects
| in realtion to idealism
an object with properties such as shape,size,location,colour etc
| these properties are sensible properties i.e. properties of sense data
52
what is berkeleys strongest arg.
| idealism
all qualities are ideas----- arg from perceptual variation AND arg that PQ depends on SQ
53
issue with 'all qualities are ideas'
1. it isnt obvious that he has established the claim that mind-independdent objects do not exist (THE ANTI-REALISM PART)
2. even if the PQ and SQ distinction does not hold, he hasnt distinguished betweehn our ideas of qualities (sense-data), and the qualities themselves (whichy are properties of the object itself)
3. furthermore there could still be an underlying foundation that causes our perception of physical objects
54
what is Berkeleys master arg
1. when we think of something, we think of it being percieved
2. therefore no one can think of anything that exists unperce4ived
3. what is perceived is in the mind
4. therefore what is thought of is also in the mind
5. therefore no one can think of anything existing outsude the mind (you cant think of an external world as this is defined as independnet of mind)
6. therefore idealism is true- everything is ideas and there is no external world
55
difference between imagination and perceiving
| master arg
we cant think of something without imagining perceiving it eg a room in your house
56
evaluating the master arg
* berkeley mixes up perception, conception and imagination
* only perception requires a picture from a perceivers perspective
* conception is a way of thinking about someting without a pciture- without seeing a perceivers perspective- e.g referring to it or reasoning with it
57
how can ID explain why hallucinations and illusions are not physical objects, if all of them are just ideas
| issues with idealism
1. according to ID, physical objects are ideas
2. however, illusions and hallucinations are also ideas in expeerince but they arent physical objects
3. ID fails to explain the difference between illusions and hallucinations and physical objects, so it implies that hallucinations and illusions are physical objects
58
response ONE to 'how can ID explain why hallucinations and illusions are not physical objects, if all of them are just ideas'
| vivid
illusions and hallucinations are less vivid than experince of real objects e.g the stick in the water looks bent but feels straight
59
# compare to other experinces
response TWO to 'how can ID explain why hallucinations and illusions are not physical objects, if all of them are just ideas'
I+H are inconsistnet with our other expereinces e.g elephants in the past looked grey and couldnt fly But now theyre pink and can fly
60
berkely argues reality is the ideas we percieve. what problem, in realtion to illusions, does this lead to?
leads to implying that illusions are physical objects and therefore that is how they truly exist in the physical world
61
what is berkely response to 'berkely argues reality is the ideas we percieve. what problem, in realtion to illusions, does this lead to?'.
claims the issue is with language - pencil in water, he claims the pencil 'looks' bent instead of the pencil 'is' bent
62
how does berkely [IDEALISM] attempt to explain hallucinations
explains that hallucinations are **not as vivid** or clear compared to perception - and they're not consistent with our past experinces
63
how can berkeley explain that objects continue to exist when no one percieves them
god
## Footnote
ideas we percive arent just caused by god, but exist as they are percieved by god
64
where do our ideas (i.e sense data or impressions) come from if not an external world?
| idealism
god
65
# simple crit.
critiscim of berkeley use of god
| idealism
its ad hoc
## Footnote
meaning its used to solve a problem with no independnt justification for the solution
66
berkeleys response to his use of god being ad hoc
his theory is an arg. for the existnece of god
1. the only possible cause of the order, regularity, and predictability of our experinces is divine intelligence
2. god is divine intelligence (omniscient)
3. so, god exists
67
problem with the role of god
| idealism
1. idealism says that physical objects which i percieve exist as ideas in the mind of god
2. but god cant have perceptual experinces like i have - e.g god doesnt feel sesnations such as pain
3. the objects i perceive change and cease to exist, but gods mind is said to be unchanging
4. therefore, what i percieve and feel cant be part of gods mind
5. so idealism is incorrect
68
berkeleys response to the problem with the role of god
| idealism
our experinces are copies of gods ideas
69
what is solipism
the claim that you only know youe own mind
70
why does idealism lead to solipism
everything we know is from experince, which is just sense data. and we have no experinces of other peoples minds
71
berkeleys response to why does idealism lead to solipism
idealism allos us to know that the mind of god exists as well as our own
72
progression of theories of perception
naive direct realism TO indirect realism TO idealism TO philosophical direct realism
73
how can illusiosn be accounted for by philosiphical direct realism
it turns out that 'looking a particular way' can be a property of an object, even when the way it looks doesnt reflect what the object truly looks like
| e.g pen looks bent in water
74
defintion of intrinsic properties
| philosiphical DR
belongs to the thing in-itslef
| e.g im 5'4
## Footnote
these properties exist in the external world
75
definition of relational properties
| philosiphical DR
belong to the thing but depends on its relationship to another thing
| eg 'im taller than a child' OR 'im smaller compared to somone who is 6'3
## Footnote
these properties exist in the external world
76
how do intrinsic and relational properties apply to the pen example
the pen looking bent in water is a relational property - due to reflection
77
response to perceptual variarion
| philosiphical DR
appearances are relational properties
* e.g a property of a rectangular table is to appear rectangular but depending on their relation to the perceiver it'll be different
78
# sense data, verdical perception
response to hallucination crit
| DR
only in hallucinations do we percive sense data, we dont in verdical pereption
* meaning DR should deny that experinces which cannot be told apart by the perceiver are the same kind of process
* despite hallucinations being able to be subjectively indistinguishable from verdical experinces, one is a direct perception of the external world and the other is direct perception of mental image
79
# form of perception
response to hallucination crit
| DR
deny that hallucinations are a form of perception at all
* perhaps when we hallucinate we do not have an experinces but rather we mistakenly imagine that we have an experince
* hallucinations are a kind of disorder or delusion where we think imagination is perception
80
response to time-lag
| philosphical DR
* can are that this response confuses what we percive with how we perceive it
* what we are perceiving is still a mind-independnt object but we're perceiving it as it was moments ago rather than how it is now
