Perception as the source of knowledge

Question 1

Direct Realism

Answer 1

Two elements in an object - perciever and the percieved

Mind-independent

Immediately percieved

Question 2

Support for Direct Realism

Answer 2

Common sense - Russell
Avoids scepticism, clear account on how we come to knowledge (our senses providing immediate access)
Explanatory power

Question 3

Issues with Direct Realism - Illusion

Answer 3

We perceive an object as having some property (crooked pencil)
In an illusion, the object does not have this property
Therefore, an illusion is a deception and a sense datum rather than a physical property
Illusions can be indistinguishable from verdical perception
Therefore we see sense data in illusions and verdical perception

Question 4

Direct Realist Response

Answer 4

The pencil has the property of looking crooked. It may look different due to how it relates to the perceiver
We perceive the looks of properties of objects, sometimes we experience the properties that dont relate to how they are perceived.
In both cases, we still directly percieve the object and its properties.
I am directly aware of the straw, the circumstances make it appear bent.

Question 5

Perceptual Variation - Russell

Answer 5

Our perception varies without corresponding changes in the object (Table at a different angle).
The properties remain the same
We aren’t immediately aware of whats infront of us, we infer.
Therefore, we dont have direct perception.
We immediately perceive sense data (content of our sensations), not the physical object.

Question 6

Berkely’s example

Answer 6

Place one hot hand and one cold hand into lukewarm water each hand will have a different sensation.
He uses this to argue that
Direct realism claims that material objects possess mind independent properties (hot and cold)
Material objects cannot be perceived to have incompatible properties ( hot and cold)
They cannot posses these inconsistencies in reality
Therefore, direct realism is false.

Question 7

Direct Realist response

Answer 7

The colour of the table is the colour it appears to be to a normal observer under normal circumstances.
When we do see colour, we see the table and its properties
In perception, we can be aware of a range of properties (some mind-independent and some mind dependent.
Sense data doesnt need to exist to explain what we perceive.

Question 8

Direct Realist Response to Berkely

Answer 8

Lukewarm water can appear to be hot/cold to the perceiver, that doesnt mean it isnt lukewarm or isnt directly perceived. Infact, this is a property of lukewarm water.
Our perception is relative to circumstances, and we can explain these circumstances.

Question 9

Hallucination

Answer 9

We percieve something having ‘property F’
When we percieve this property, we perceive something that has the property.
But we dont see physical objects in hallucination
Therefore, what we perceive must be mental (sense data)
Hallucinations are often indistinguishable from reality
Therefore, we see sense data in both hallucination and verdical perception

Question 10

Direct realist response

Answer 10

Whats perceived is physical eg light waves
Should we say we perceive the object indirectly, and the medium directly?
Confusion between what we perceive and how we perceive
Only shows that we can perceive the past

Question 10

Direct Realist response

Answer 10

Hallucination and verdical perception are different mental states
They can be seen the same, but this doesnt prove that they are the same
Hallucinations tell us nothing about perception

Question 11

Time lag

Answer 11

It takes time for light waves, smells etc to get from objects to our senses
We can percieve something after it seizes to exist (distant stars)
What is true of distant objects is true of close objects
Therefore, we dont directly perceive objects

Question 12

Indirect Realism

Answer 12

Mind-independent
perception is made up of:
The perceiver
The real object perceived
The appearance of the object perceived
Perception involves inference, so must be indirect
Sense-data are private, and only exist when being experienced

Question 13

Primary Qualities - Locke

Answer 13

Inseperable from the object
Stays the same regardless of change in object
Size, shape,position, motion

Question 14

Secondary qualities - Locke

Answer 14

The sensation causes sense-datum in our minds isnt actual sense data
Ideas/sensations
Vanish without being perceieved
Caused by primary qualities
Colour,smell,taste

Question 15

Support for Locke

Answer 15

Primary qualities are essential
Dividing an object to be miniscule still retains primary qualities
Secondary Qualities rely on primary qualities, and a mind to perceive them
eg. almond.
Taste and colour change along side shape if we crush it

Question 16

Criticism

Answer 16

If change shows a quality is secondary, we should regard the shape and size as mind-dependent
Just because SQ depend on PQ doesnt mean they are purely mind dependent - they are more reasonably objective properties

Question 17

Issues with indirect realism - Scepticism about the existence of mind-independent objects

Answer 17

-We must know objects exist to know they cause sense data
How can we know this if our only access to objects is through sense-data?
The veil of perception

Question 18

The Veil of Perception

Answer 18

The idea that the sense data a perceiver sees is caused in you by atoms and void, and we only see how the world looks to us, not the actual world

Question 19

Indirect Realist Response - Involuntary nature of experience

Answer 19

We are’nt in control of our sense data
Perception is not subject to my will, so it can’t come from within me, so the source of a sensation is external

Question 20

Objection

Answer 20

Only inference to say theres a material reality
Just because we can’t control our senses doesnt mean there is a material reality
Dreams aren’t in our control, but we see the same objects
Doesn’t tell us what causes sense data

Question 21

Response 1

Answer 21

Waking life is more vivid, evidence of it being caused by external reality eg. being in a fire

Question 22

Response 2 - Locke and Cockburn

Answer 22

Coherence of Experience
Other people see the same thing I do, its reasonable to suppose a real object is causing our perceptions
Appeals to the way our sense cohere eg. seeing a fire, feeling the heat
Cockburn says objects feel the way they do eg. a dice
Our senses support independently for eachothers testimony, suggesting an external cause on both our perceptions

Question 23

Objection

Answer 23

How do we know other people and physical objects exist?
The fact I cant control my sense experience and senses cohere doesn’t mean they must be caused by material reality - inference goes beyond evidence
Dream argument - dont correspond with material reality
We need to see past the veil of perception to compare our sense data to reality.

Question 24

Molyneux Problem (Objection to Coherence of Experience)

Answer 24

If someone is born blind, they have many tactile experiences eg. holding a football If their sight is restored, will they recognise its a football without touching it?

Question 25

Response from Locke

Answer 25

No - we learn from experience 2 different experiences Our visual idea of a football and tactical idea resemble eachother, so our senses collaborate elsewhere he says Visual and tactile ideas have nothing to do with eachother and we associate them together through experience

Question 25

Trotter-Cockburn

Answer 25

We learn to associate the way objects feel to the way they look She didnt think senses resemble eachother (Locke did) and that because our senses dont resemble eachother, a blind man would be able to recognise a sphere The sense correlation means that these experiences of a regularly go together. You can have visual experience of a sphere and safely predict you will have a tactile experience of a sphere

Question 26

Response 3 (to criticisms of IR) - Russell

Answer 26

We have instinctive belief belief in the existence of a material reality which corresponds with our sense data and we should only reject such instinctive beliefs if they are proven to be incoherent The hypothesis that objects exist and cause my sense data are simpler and fits with evidence, as well as accounting for our experience

Question 27

Criticism against Russell - Sceptisim about the nature of mind independent objects

Answer 27

If i can doubt that our perceptions of Secondary qualities resemble reality, what prevents concerns about primary qualities? The only way to know how good perceptual systems are at representing the world, we need to compare reality to representation. We cant, due to the veil of perception.

Question 28

Berkely's criticism against Russell - Sceptisim about the nature of mind independent objects

Answer 28

Our belief of the world is incoherent We only ever have direct awareness of our sense data All sense data (including PQ) depend on our mind The qualities we perceive in objects require a perceiving mind to exist Since matter is said to be unperceiving, it cannot have such qualities

Question 29

Berkely's likeness principle

Answer 29

A tree, for example, has certain sensible qualities These qualities depend on the mind To say my idea of a tree resembles the real material tree is like saying something visible represents something invisible - incoherent Ideas are changing, whereas material objects are supposedly permanent and unchanging Thus anything outside the mind (matter) cannot have any of these qualities It follows the idea that a supposed material object could not be like or resemble my idea of it

Question 30

Idealism - Berkely

Answer 30

Everything that exists is mind-dependent To be is to be perceived Focuses on sense data - calls them ideas

Question 31

Secondary Qualities - Berkely

Answer 31

Berkely suggests that the ideas of unfelt pain/smell are not coherent, they require there to be senses and minds Our perception is entirely smells, colours and sounds

Question 32

Primary Qualities - Berkely

Answer 32

Essential to an object Equally as incapable of perceiving objects without secondary qualities, so PQ and SQ must be inseperable and essential to our idea of objects PQ's are mind dependent as it depends on your size, position etc

Question 33

Everything is Mind dependent - Berkely

Answer 33

P1 Everything we perceive is either a primary or secondary quality P2 Both P and S qualities are mind dependent C therefore nothing we perceive exists outside the mind

Question 34

God - Berkely

Answer 34

The universe is only constant because God is perceiving it at all times

Question 35

Support for IR over Idealism

Answer 35

If we are careful to disntiguish the ideas/ sesnse data and qualities of objects that cause them, berkelys idea is flawed Locke isnt saying that SQ themselves are mind-independent, rather secondary qualities are the powers in an object that cause sensation in us and are mind-independent So the fact they are both perceieved by me doesnt mean that both sets appear in the mind They exist in the mind, but the qualities themselves are independent.

Question 36

Perceptual variation against Idealism

Answer 36

Berkely runs a parallel argument to perceptual variation and argues that shape, size etc (PQ's) are subject to perceptual relativity, not just SQ's

Question 37

Perceptual variation against idealism 2

Question 38

Criticism

Question 39

Master Argument

Question 40

Criticism of Master Argument

Question 41

Criticism of Likeness principle