Perception as A Source Of Knowledge (no idealism)

Question 1

What are Philosophers of perception divided into?

Answer 1

Philosophers of perception divided into ‘Realists’ and ‘Idealists’
Realists claim we perceive physical objects, which exist independent of our minds and our perceptions.
Idealists argue that physical objected are not independent of our minds + that there mental things that’s why they perceive them.

Because Idealists denies that physical objects exist independent of our minds, its also known as ‘Anti- Realist’.

So theres;
Direct Realists
Indirect Realists
Idealists

Question 2

What is Direct Realism?

Answer 2

Direct Realism is the theory of perception that we perceive physical objects immediately and as they are without anything in between the objects (eg sense impression) we are directly viewing it as it is. ( argues objects exist Objectively.

• Its existence + nature is independent of us perceiving it (whether or not we looking at it)
• We perceive physical objects and external world directly
• Gain knowledge via perception of the world.
• Tastes, sounds, colours are all in the objects/a part of it (not just perceived in the mind)

Question 3

What is Indirect Realism?

Answer 3

Indirect realism claims physical objects are mind independent but we do so via perceiving mind-dependant sense-data that represent physical objects indirectly. ( sense-data between us + the object).

• There many perceptual experiences in which what we experience are not properties of physical objects
• When we perceive something having that property (f) then there’s something w the property (f)
• Given that we perceive is not the way the world is, what we perceive is sense-data.
• When 2 perceptual experiences are subjectively indistinguishable they are perceptual experiences of the same thing therefore what we perceive is always sense data. ( except in hallucinations it still makes sense to say we perceive the world via sense data caused by physical objects. so we perceive physical objects indirectly in sense data.

Question 4

Whats Direct- realisms argument for there theory?

Answer 4

DRealists would claim its common sense to say we perceive physical objects independently in our minds. Cosmology + Evolution states that physical objects eg stars + planets existed billions of years before humans + before our minds existed for us to be able to experience them. And we do generally believe physical objects continue to exist despite us not looking at them, therefore they don’t disappear when we look away.
Therefore physical objects exist OBJECTIVELY of our minds.

Question 5

State the criticsims/ arguments against Direct Realism.

Answer 5

• Perceptual Variation
  (+ Locke’s examples for distinction between primary/secondary qualities via Grain of Wheat + Basin example)
• Argument of Illusion
• Argument of Hallucination
• Time- Lag argument

Question 6

Explain the criticism of Direct realism ‘ Perceptual Variation’

Answer 6

Perceptual variation argues “what we see isn’t what is out there”
Russel uses example of ‘ Shiny Brown Table’
Table is brown, but it doesn’t actually look brown across the entire table. Lighting , viewpoints etc changed its appearance of colour, so saying its a brown table is no more then saying ‘ looks brown to a ‘normal spectator’ Therefore brown is more real property of the table rather than colours you see.

Problem of brown table - highlights the table should look the same colour + texture etc if its directly inform of us + were perceiving it as it is. If it can be different for every individual looking at it then it is not Direct Realism
( applies for textures too because from far it can appear smooth but up close in microscope bumpy + ridged).

Question 7

What would Direct Realists response be to the argument of Perceptual Variation.

Answer 7

DR would argue;
objects ‘ change’ when we perceive them at different + alternating angles - there’s a reason for this.
Natural objects like Hay is yellowy brown but can appear completely different mixes of shades depending on if suns hitting it, if there’s sunrise etc.
It is the CONDITIONS which change how we perceive physical objects not the objects ever changing themselves.
Therefore objects only ever change due to different viewpoints, perspectives + conditional being inflicted upon them.

Question 8

What would Indirect Realists respond to Direct Realisms claims that it is the ‘Conditions’ which ‘change’ physical objects?

Answer 8

Indirect Realists would argue there’s a
‘Distinction Between Appearance Vs Reality’

Indirect Realists argue ‘Sense-Data’ is what were immediately aware of when perceiving something such as a table. The visual sensation is sense data and the sense- data is how we perceive an object to be(so dependant on individual)
So can summarise argument by saying Perceptual variation shows that what we directly perceive is not physical objects but sense data + Thus aren’t seeing physical objects directly as Direct Realists claim.

Question 9

Explain the argument against Direct Realism ‘ Argument of Illusion’

Answer 9

Illusions are ‘Subjectively Indistinguishable’ from Veridical Perception (represents the world+ how it acc is Therefore provides argument against Direct Realism ( cause cant tell difference thus cant guarantee perceiving objects directly as they acc are)
Eg - of u put pencil in water it appears bent but isnt.

P1 - if we perceive something as having property (F)
P2 - Then object has that property
Therefore in illusions what has that property(F) is something mental therefore in Illusions we see Sense-Data not physical objects
P4- Illusions = subjectively indistinguishable from veridical perception.
P5 - Therefore we always see that same thing whether its sense data or veridical perception therefore in all cases we see sense-data not physical objects directly or immediately so Direct Realism is false.

Question 10

What would Direct Realists response be to the criticism of Illusion?

Answer 10

DRealists would say that when a pencils in water + appears crooked there’s no actual part of it which is crooked therefore (PT2) of the argument of Illusion is wrong. Instead the property of ‘looking crooked’. There’s a key difference between something ‘Appearing’ Vs ‘Being.

Question 11

Explain the Argument of ‘Hallucination’ against Direct Realism.

Answer 11

Argues we can experience perceptual hallucinations not just visual ones but auditory and olfactory hallucinations as well which can also be subjectively indistinguishable from veridical perception (so n way of knowing its all a hallucination)
P1 - In hallucinations we perceive something having property(F)
P2 - If we perceive having property(F) then it has property (F)
P3 - In hallucinations we don’t perceive physical objects at all
C1 - thus what we see must be Sense-Data
P4 - Hallucinations can be experiences completely subjectively indistinguishable from veridical perception
C2 - we see the same thing (sense-data) + veridical perceptions in both so not all physical objects are immediately perceived so Direct realisms False.

Question 12

What is the Disjunctive Theory Of Perception? + why does it strengthen Direct Realism and undermine the Argument of Hallucination?

Answer 12

Disjunctive Theory;
-States hallucinations + veridical perception are 2 completely different kinds of mental state;
in hallucinations the person isnt connected up to the world and though it can seem the same it doesn’t prove they are the same. To imagine something isnt to perceive something mental (eg sense-data) but not to perceive anything at all.

• We can use Disjunctive theory to challenge the conclusion of the Hallucination argument against direct Realism because the hallucination argument doesn’t show that in veridical perception we perceive physical objects instead of sense-data.
• Also in many circumstances we are able to identify a hallucination eg by grabbing hallucinated object and immediately knowing if its a real physical object.

Question 13

Explain Locke’s 2 examples for the distinction between Primary and secondary qualities ( Grain of Wheat + Basin example)

Answer 13

Locke argues there’s a clear distinction between primary and secondary qualities and therefore against Direct Realists. Direct realists argue qualities are in the physical objects themselves + cannot act for secondary qualities. Locke argues that the secondary qualities of objects produce ideas in our minds + what we see a representation of the objects colour in our mind not the real thing so its something mental thus disproving direct realism.

GRAIN OF WHEAT EXAMPLE;
Locke uses grain of sand and says if you cut it up again and again until you can no longer see it the secondary qualities such as smell, taste or colour change or can even vanish however primary qualities of it such as mass and space it occupies never changes regardless of secondary qualities. Locke believes this distinction that they are completely different things and thus not equal.

THE BASIN EXAMPLE -
Locke illustrated secondary qualities by using basins.
There’s 3 basins one with hot, cold and warm , if you put one hand in hot and another in cold and after a min you put them both in warm then they will feel completely different temperatures even though there both in the same warm water showing temperature is actually a secondary quality(can change) your hand will feel hot in one basin and cold in the other even though physically the water is the same temperature for both hands thus temperature depends on your subjective experience and therefore is an example of a Secondary Quality and that theres thus big distinction between the two so Direct Realisms flees..

Question 14

What is the difference between Primary and Secondary qualities?

Answer 14

Primary qualities are ‘utterly inseparable’ from the object regardless of any changes it goes through;
Shape,number,motion and solidity

Secondary are qualities that physical objects have but they are ‘nothing but powers to produce various sensations in us’
Colour,sound, taste,smell and temperature.

Primary qualities are in the physical objects themselves and so dont depend on how an individual views/perceives them. They don’t change.

Locke proves temperatures a secondary quality with his ‘Basin Example’ because it changes

Solidity on the other hand is Primary as it is unchangeable and a part of the physical object + takes up space.

Question 15

What is Indirect Realism’s argument In premises + conclusions?

Answer 15

Sense data - mental things which are exact we way perceive them to be so there appearance + reality is as it seems) but in contrast physical objects can appear different t how they really are.

P1) Theres many perceptual experiences which we experience but aren’t properties of physical objects
P2)When we perceive something as having property(F) then there is something w that property (F)
C1 Given that what we perceive is not way the world os, what we perceive is actually sense-data

P3) In cases like this there subjectively indistinguishable from veridical perception
P4) Perceptual experiences are subjectively indistinguishable they are perceptual experiences of the same thing
C2) Therefore what we perceive is already sense-data

P5) Nevertheless, in hallucinations, it still makes sense to say we perceive the world, in cases of both veridical perception + illusion the sense data can be accurate or inaccurate as physical objects may appears they are or they may differ.

C3) Therefore, we perive physcial objects indirectly via sense-data.

Question 16

Explain the criticism of Indirect Realism ‘skepticism about the nature of mind independent objects’

Answer 16

Scepticism about nature of mind-independent objects/ the external world:

If we never price the external world or physical objects directly they could be completely distinct from what were actually seeing. We can’t know what external objects are like. We don’t know what’s behind our sense impressions.

Question 17

State the counter/argument against the critics of Indirect Realism External world

Answer 17

• Russell’s response ‘ The existence of External world is best hypothesis’
• Locke’s 2 supporting arguments;
  Locke’s argument for Involuntary nature of our experience + argument for coherence of various kinds of experience.

Question 18

Explain Russels argument for existence of external world

Answer 18

Russel argues
- Complete proof is beyond us but it is reasonable to believe in the external world + this explains why we have sense data and why they behave in Regula + Predictable ways.
- Either physical objects exist + cause our sense-data or they don’t and so don’t cause sensedata.
we cant prove either as absolutely true/false therefore have to treat it as hypothesis that physical objects exist + cause my sense data, therefore physical objects do exist + cause my sense data!

For Russel the existence of the External world is the best explanation going + so the material world(everything exists regardless if were perceiving it).

Apple example;
If you leave an apple in desk for month and come back it will be rotted. Best explanation= bacteria got to it and cause decay over time
Although Russel acknowledges possible replies like;
dreaming, solipsism or evil demon
there’s no substantial reason to support these theories and the BEST alternative is always to say there’s an external world + it exists.

Question 19

Explain Russels argument for existence of external world

Answer 19

Russel argues
- Complete proof is beyond us but it is reasonable to believe in the external world + this explains why we have sense data and why they behave in Regula + Predictable ways.
- Either physical objects exist + cause our sense-data or they don’t and so don’t cause sense- data.
we cant prove either as absolutely true/false therefore have to treat it as hypothesis that physical objects exist + cause my sense data, therefore physical objects do exist + cause my sense data!

For Russel the existence of the External world is the best explanation going + so the material world(everything exists regardless if were perceiving it).

Apple example;
If you leave an apple in desk for month and come back it will be rotted. Best explanation= bacteria got to it and cause decay over time
Although Russel acknowledges possible replies like;
dreaming, solipsism or evil demon
there’s no substantial reason to support these theories and the BEST alternative is always to say there’s an external world + it exists.

Question 20

Explain Locke’s 1st supporting argument for the existence of the external world.

Answer 20

Involuntary nature of our experience;

Knowledge of the external world, according to Locke, is knowledge of the existence of something distinct from our mind (and so, of course, distinct from the ideas in our mind).

Locke notes that in perception;
- I cannot avoid having certain sense-data(impression) that are produced in my mind
But if I change from perception to memory / imagination then i can choose what i want to experience.
- However the perceptual experiences tat i have regardless of if i want to must be produced by exterior/ cause
That cause/exterior = physical object
proving there’s an external world(cause we cant acc control it)

Question 21

Explain Locke’s 2nd supporting argument for existence of external world - The argument for coherence of various experiences;

Answer 21

The argument for coherence of various experiences;

• Normally when your deceived i.e. In cases where we hallucinate usually only 1/5 sense is deceived eg our sight. However in the real world as stated by Catherine Trotter Cockburn we always utilise all of put sense together (collectively) for us to judge what’s reality + that there is an external world.
  e. g. a dog jumping on you in the park, firstly you can smell the dog, secondly you feel it lick you, thirdly you can hear it - the point is you know that the dog is real + therefore that there’s an eternal world which causes our experiences.

Question 22

Explain Critiscm against Indirect Realism that it ultimately leads to skepticism about the existence of the external world

Answer 22

If everything i perceive is ultimately mind-dependent sense data do i have any reason to think that anything exists apart from my own mind. Indirect realises claim that what we price is always something mental paves the way for the possibility that our minds are what creates reality + thus the possibility only your mind is guaranteed to actually exist.

Question 23

Explain the Time-Lag Argument against Direct Realism

Answer 23

Time-Lag shows that;

When we look at the sun we are actually seeing it in the past thus as it was 8 mins ago an therefore not directly as it is - despite he fact were looking directly as it in that moment.

Both the Sun + Nebula may have ceased to exist but i would still be able to perceive the as they were 8 mins in the past if i were looking t them
Therefore this is a mental image (sense-data) that were perceiving (as Indirect Realism claims) and not the Real physical object.

Direct Realists would respond by saying we can accept a lag in perception but this doesn’t mean that we need sense-datum it just mean we cannot see objects instantaneously.