epistemology perception as a source of knowledge

Question 1

key term- immediate objects of perception

Answer 1

means the things which we perceive directly.

Question 2

support for direct realism

Answer 2

+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.

Question 3

Problem- Bertrand Russel perceptual variation ( criticism)

Answer 3

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

Question 4

possible response to russel relation properties

Answer 4

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

Question 5

argument from illusion (criticism)

Answer 5

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.

Question 6

possible response illusion criticism

Answer 6

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.

Question 7

argument from hallucination

Answer 7

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).

Question 8

summary hallucination (arugment structure)

Answer 8

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.

Question 9

time lag argument

Answer 9

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.

Question 10

time lag summary (argument structure)

Answer 10

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.

Question 11

time lag response

Answer 11

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.

Question 12

indirect realism meaning

Answer 12

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.

Question 13

indirect realism summary

Answer 13

• 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.

Question 14

sense data overview

Answer 14

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.

Question 15

what are lockes primary qualities?
(objective)

Answer 15

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

Question 16

what are Locke secondary qualities?
(subjective)

Answer 16

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

Question 17

what does locks primary and secondary qualities illustrate?

Answer 17

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.

Question 18

support for Lockes primary qualities

Answer 18

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.

Question 19

support for locked primary qualities in summaries argument structure

Answer 19

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.

Question 20

support for locked secondary qualities distinction

Answer 20

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.

Question 21

support for locked secondary qualities in argument structure

Answer 21

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.

Question 22

What is a problem for indirect realism?

Answer 22

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

Question 23

PROBLEM: SCEPTICISM overview/ key points

Answer 23

• 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.

Question 24

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

Answer 24

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.

Question 25

What is the veil of perception and trap of solipsism?

Answer 25

“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”.

Question 26

response issue of sceptisicm

Answer 26

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)

Question 27

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

Answer 27

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.

Question 28

The coherence of various kinds of experience: Lockes viewpoint

Answer 28

-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.

Question 29

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

Answer 29

-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.

Question 30

What is idealism?

Answer 30

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.

Question 31

George Berkeley - idealism

Answer 31

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.

Question 32

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

Answer 32

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.

Question 33

what is solipsism?

Answer 33

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

Question 34

problems for idealism: SOLIPSISM

Answer 34

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.

Question 35

hallucination and illusion responses to Berkeley’s Idealism

Answer 35

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?