epistemology perception as a source of knowledge Flashcards

1
Q

key term- immediate objects of perception

A

means the things which we perceive directly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

support for direct realism

A

+avoids scepticism: we know about it because our senses provide immediate access to its true nature.
+has explanatory power: if im directly aware of physical reality + its properties explains why i can execute range of practical daily actions e.g finding food.
+explains why i percieve what i do: e.g i see the tree is green because the tree is green.
+explains why we agree about what we percieve and is in tune with out senses that occupy same universe as everyone else.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Problem- Bertrand Russel perceptual variation ( criticism)

A

differences in perceptions variation provide a problem for direct realism
e.g when i stand on one side of the room a shiny wooden table may have a white spot where the light is shining on it. But to someone standing on the other side of the room there may be no white spot.
But the white spot is either there or it isn’t - it can’t be both!
means = one of us is not perceiving the table directly as it is.

Russel more examples with the table:
shape of the table- from directly overhead may appear rectangular. few meters away may look kite-shaped.
Again- can’t be both
examples: highlight the differences in our perception.
according to direct realism: there should be no differences between perception and reality.
all these variations in perception suggest that there is no real way to perceive the world

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

possible response to russel relation properties

A

direct realism can respond by refining the theory and introducing the idea of relational properties.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

argument from illusion (criticism)

A

DR says we percieve the external world directly as it is. If true how is it that reality can be different to our perception of it?(Ayer)
Example : when a pencil is placed in a glass of water, it looks crooked. But it isnt really crooked.
If direct realism is true, the external world would be exactly as we percieve it. However in case of illusion there in an obvious difference between perception + reality.
If things appear to be different from the way they actually are then we dont periceve the world itself accuaretly: we percieve sense data. Therefore, direct realism is false.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

possible response illusion criticism

A

Direct realist could reply that the pencil has the relational property of looking crooked to certain pericevers (even tho it isnt). In the example, direct realism would argue it appears bent because we are accurately percieving light refraction.
+ we can occationally misinterpret what we periceve.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

argument from hallucination

A

more extreme version agrument from illusion. DR says when we percieve something we are percieving something in the external world (directly). But during halluctions- we percieve things that arent even there.
Whats causing these perceptions? It cant be the external world - at least not directly- because there is no external object being percieved at all.
Argument points out- hallucinations (illusory perceptions) are often qualitavely indistguishable from verdical perceptions (i.e hallucinations look as realistic as real objects do).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

summary hallucination (arugment structure)

A

p1. direct realism states that we percieve the world directly + accuartely.
p2. In an illusion, we percieve an object as having particular properties.
p3. the real object does not have these properties/ no such object exists
p4. if things appear to be different from the way they actually are, then we do not percieve the world accurately.
c. Therefore, direcet realism is false.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

time lag argument

A

The sun is 149,600,000km from earth. Light travels at 299,792,458 meters per second.
This means it takes approximately 8 minutes for light to reach earth. So, when you look at the sun, you are seeing it as it was 8 minutes ago- i.e there is a difference between the sun itself + your perception of it. In other words you are not percieving the sun directly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

time lag summary (argument structure)

A
  1. direct realism states that we percieve the external world directly, immediately + accurately.
  2. light from stars + other distant objects takes so long to reach our eyes that we cannot see them as they are at the moment.
  3. If things appear to be different from the way they actually are, then we do not percieve the world directly + accurately.
  4. Therefore, direct realism is false.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

time lag response

A

the direct realist can argue that this response confuses what we percieve with how we percieve it. Yes, we percieve objects via light + sound waves + yes, it takes time for these light + sound waves to travel through space. But what we are percieving is still a mind-independent object- it’s just we are percieving it as it was moments ago rather than how it is now.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

indirect realism meaning

A

the view that:
- the external world exists independently of the mind (hence, realism)
- but we percieve the external world indirectly, via sense data (hence, indirect).
Indirect realism says the immediate object of perception is sense data. This sense data is cause by + represents, the mind-independent external world.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

indirect realism summary

A
  • realist theory. so, retains the belief that material objects exist independently of the mind.
  • however draws distinction betwee reality of these objects + the way they appear.
  • 3 elements in perception: perciever, real objects that they periceve, also appearance of objects to the perciever.
  • what we are directly aware of are appearances, locke ‘ideas’ and russel ‘sense data’. r representations of reality.
  • must infer, on the basis of these sense data, the nature of reality. because perception invovles this interference it is indirect.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

sense data overview

A

sense data =the content of perceptual experience
not a psysical thing, exists in the mind. can be caused by + represent mind-independent objects.
sense data private and individual.
john locke distinction of primary + secondary qualities.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are lockes primary qualities?
(objective)

A

properties inherent in the object itself
-size
-shape
-motion
-number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are Locke secondary qualities?
(subjective)

A

powers of an object to cause sensations in humans
- colour
-taste
-smell
-feel

17
Q

what does locks primary and secondary qualities illustrate?

A

One example is porphyry= a red and white stone.
Locke says when you prevent light from reaching porphyry “its colours vanish”. However primary qualities remain.
his distinction between P + S qualities used to support INDIRECT REALISM.

18
Q

support for Lockes primary qualities

A

Locke- primary qualities are ‘utterly inseparable’ from an object. Means that - however the object is altered its parts must retain some shape, size, position and so on, even if we can no longer see the parts. without the qualities it wouldn’t be material at all. Therefore, primary qualities must be essential to material objects and are retained by the objects wether or not anyone perceives them.

19
Q

support for locked primary qualities in summaries argument structure

A

P1 if you continually divide an object the parts must retain the primary qualities even when they are too small to be perceived.
C therefore primary qualities must exist mind independently.

20
Q

support for locked secondary qualities distinction

A

By contrast secondary qualities do alter or vanish. colours are only visible in the light and change depending on light. So Locke concludes the secondary qualities both depend on the primary qualities and require a mind to appear and so are not in the objects themselves as we perceive them.

21
Q

support for locked secondary qualities in argument structure

A

P1 when we pound an almond we merely change the shape of its parts.
P2 but the colour and taste of the almond also change.
C so, the change in colour and taste is caused by the change in the shape of the almonds parts.

22
Q

What is a problem for indirect realism?

A

Problem for indirect realism is that it leads to SCEPTICISM about the nature and existence of the external world.

23
Q

PROBLEM: SCEPTICISM overview/ key points

A
  • according to indirect realism we are directly aware only of sense data + must infer the existence of objects beyond the mind.
    -however, our senses can deceive us.
    -worse, it is conceivable that our sense data do not correspond with any material reality, if for example my brain is in a vat or there is a powerful demon bent on deceiving me.
    -these possibilities show that the interference is not valid and so not sufficient for knowledge.
24
Q

problem: scepticism
what is the ‘veil of perception’?

A

We only know what e are directly aware of. Since we cannot directly observe reality we cannot know it exists. = called veil of perception is the problem for it says that our sense data constitute a veil between us and reality which we cannot penetrate to discover the material world.

25
Q

What is the veil of perception and trap of solipsism?

A

“all we have direct access to are our own sensations. We cannot peer peer beyond the veil of perception to perceive the world as it really is. But is we cannot penetrate the veil of perception, then not only can we not know what the world is really like but we can never know that the real world exists at all. Perhaps something else entirely is causing our sensations”.

26
Q

response issue of sceptisicm

A

Locke involves pointing out that we are not in control of our sense data. If I open my eyes I will receive certain sense data and this is not something I have any choice about. Because perception is not subjective to my will, Locke argues, it cannot come from me. And therefore, the source of sensation must be external. (involuntary nature of experience)

27
Q

Second response to issue of scepticism.
The coherence of various kinds of experience (Cockburn)

A

appeals to the way our different senses cohere with each other.
-For example, Locke observes we can both see a fire and feel its heat.
-Catherine Cockburn also observes that we learn to associate the way objects feel to the touch and the way they appear to the eye.

28
Q

The coherence of various kinds of experience: Lockes viewpoint

A

-Locke is aware these are not deductively valid arguments. The fact I cant control my sense experiences + they cohere with each other doesn’t entail they must be caused by material reality. This inference goes beyond evidence. After all, when I dream, our sense experience are not subject to the will = I cannot control my dreams. In a dream I may appear to see, hear + feel the same objects. Despite this, dreams don’t correspond with material reality.
-However, Locke hopes hes done enough to show that the inference of the existence of mind-independent objects is reasonable + as good as creatures of limited faculties can attain. Locke favours the reality of matter, by far the best explanation of our experience than any alternative, such as that it all a dream.

29
Q

The coherence of various kinds of experience: Russels support for Lockes viewpoint

A

-Like Locke R argues the existence of the external world is the ‘best hypothesis’. R argument doesnt prove that conclusion for certain; rather, the conclusion seems like the best explanation available.

Argument summarised:
1. We have perceptions which generally cohere with each other.
2. We have perceptions which seem to cohere with other people’s perceptions.
3. We have perceptions which have continuity over time.
4. Either we percieve the external world, or our perceptions are illusory.
5. Therefore, the external world exists + we perceive it.

30
Q

What is idealism?

A

Is the view that:
- there is no external world independent of minds (anti realist theory)
-We perceive ideas directly
In other words the immediate objects of perception are mind-dependent ideas.

31
Q

George Berkeley - idealism

A

He provides various arguments against mind-independent external world.
- variation of the sceptical argument. B asks how- if realism is true- we can link up our perception with objects behind it. Cant look past veil of perception.
-Challenges Lockes P + S qualities, arguing so-called primary qualities are equally mind-dependent as S qualities.
-Master argument: the very idea of mind-independent objects is inconceivable + impossible.

32
Q

Berkeley (2): To be is to be perceived (or to perceive)

A

Suggests that an unexperienced object is as nonsensical as an unfelt pain.
B concludes objects are simply ideas a critic might say it is counter-intuitive to suggest that objects flit in + out of existence as I close my eyes. The continuity of objects suggests that the real world does continue to exist unperceived.
B response- God percieves the world all the time + so objects do continue to exist when humans arent perceiving them.

33
Q

what is solipsism?

A

Is the view that one’s mind is the only mind that exists.

34
Q

problems for idealism: SOLIPSISM

A

In berkeleys earlier argument suggested that there is no reason to believe anything exists beyond ones experience. Berkeley accepts that I have no idea of a mind. But because I am a mind ‘thinking substance’ - I know I exist.

Argument structure:
P1. The mind is that which (actively) percieves, thinks + wills, while ideas are passive.
P2. I am aware of myself as capable of this activity.
C1. Therefore, I am not my ideas but a mind.
P3. Being a mind myself, I have a ‘notion’ of what mind is.
C2. Therefore, it is possible that other minds exist.
P4. My perceptions dont originate in my mind.
C3. Therefore, they are caused by some other mind.
C4. The complexity, regularity, ect, of my experience indicates that this mind is God.

35
Q

hallucination and illusion responses to Berkeley’s Idealism

A

Illusion (crooked pencil): B answer the pencil would look crooked under normal conditions. Since this is fake, we should say “the pencil looks crooked” to avoid this implication.
Hallucination: as B contends ‘ to be is to be perceived’ are we to say hallucinations are just as real as ordinary perception? Also why would God cause such perceptions?