Knowledge From Perception

define direct realism

the external world exists independently of the mind and we perceive the external world directly eg when i see a tree i am seeing a tree that exists in the external world the exact same way i am perceiving it

define mind independent objects

objects which exist in the external world and aren’t reliant on the mind to exist

what are the criticisms to direct realism?

RUSSELL: perceptual variation

illusion

hallucination

time lag

what is the argument from perceptual variation?

RUSSELL: if i look at a table directly above it i will see a rectangle

if i look at the same table from a few metres away, i will see a kite

it can’t be both shapes at the same time

so one of these perceptions is not perceiving the table directly

so there are differences between our perception and reality

but direct realism claims reality and perception are the same so direct realism is wrong

what is the counter argument to perceptual variation?

mind independent objects can have relational properties

this means the object does not change but rather you are the one changing. relational properties are properties which vary according to something else but they are not real permanent properties, they are subjective

since the object is not changing, it is still real and mind independent

eg the table has the relational property of being rectangular or diamond shaped but its real shape stays the same

what is the argument from illusion? and its counter argument?

direct realism says that we see the world exactly as what it is

but illusions show that we can perceive the world differently to how it actually is

eg a pencil in water looks bent but it is actually straight

so there is a difference between perception and reality

CA: example of relational properties eg pencil has the relational property of looking bent

what is the argument from hallucination? and its counter argument?

during hallucinations we perceive things which aren’t there

eg schizophrenics sometimes see people who don’t exist

the external world is not directly causing this perception as the object does not exist

so direct realism does not work

CA: hallucinations do not cover all of our sense so we do not perceive them fully as we would with mind independent objects

what is the time lag argument? and its counter argument?

it takes around 8 minutes for light to reach the earth from the sun

so when you look at the sun you see it 8 minutes ago

if there was an explosion you would still see the sun as it is now for 8 minutes even though it would no longer exist

so we don’t perceive everything directly

CA: what you perceive is still a direct mind independent object

how you perceive it is not direct but that does not matter

define sense data

the content of a perceptual experience, is caused by the external world and represents it (also called the veil of perception as it is what seperates the external world and our perceived world)

define indirect realism

there is an external world that exists independently of the mind and we perceive the world indirectly via our sense data. the external world and the world we perceive are two different things.

define primary qualities

qualities that are inherent in the object itself (mind independent) eg size, shape

define secondary qualities

powers of objects to cause sensations in humans (mind dependent) eg colour, smell

what is an example which helps explain primary and secondary qualities?

it is theorised that different smells are caused by different shapes of molecules which bind to receptors

these molecules have the primary quality of their shape

but they do not have the primary quality of being coated in a smelly substance - the shape has the potential to cause the sensation of smell in humans

so smell is a secondary quality

who came up with primary and secondary qualities?

LOCKE

how do primary and secondary qualities show indirect realism is better than direct realism?

a direct realist would argue that secondary qualities like colour are inherent in objects themselves since we perceive them

however we know this is wrong since secondary qualities change like when colour disappears in a dark room

indirect realists explain this occurrence with the distinction of primary and secondary qualities since secondary qualities are mind dependent like the sense data which indirect realists say we have

what are the criticisms to indirect realism?

scepticism about the existence of mind independent objects ( DESCARTES evil demon)

BERKELEY scepticism about the nature of mind independent objects

what is the criticism about the scepticism of the existence of mind independent objects?

DESCARTES evil demon: suppose there is an evil demon bent on deceiving me and so he messes with my sense data so nothing i perceive is actually real

if this were the case, nothing would reveal this to me as my sense data is all i can perceive and it is being controlled

if we can’t be certain that there is no one controlling our sense data, we can’t be certain that the external world is actually real

what are the counter arguments to scepticism about the existence of mind independent object?

LOCKE : involuntary nature of our experiences

LOCKE + COCKBURN: coherence of various senses

RUSSELL: external world is best hypothesis

what is the involuntary nature of our experiences counter argument? and its CA? and CCA?

LOCKE: sense experience can’t be controlled eg in my imagination, i can envision a rose on the table but in real life, i can’t just look at a table and expect a rose to just appear however much i want it to

since sense experiences force themselves onto us they ‘ must be produced in my mind by some exterior cause’ so mind independent objects must exist

CA: when we dream we can not control what is happening even though the dream is mind dependent. so just because we can’t control our perception of the world doesn’t mean the world is mind independent as we could be dreaming

CCA: LOCKE says if you thought you were dreaming and in a fire you could touch the fire and if doesn’t hurt it means you are dreaming but if it does, it means you are not dreaming

since we have an aversion to pain, Locke argues that we can know we are not dreaming since we would have no concept of pain if we didn’t so the dreaming counter argument fails

what is the coherence of various senses counter argument?

LOCKE: different senses confirm the information of one another

eg if i write the word ‘tree’ on a piece of paper and someone reads aloud ‘tree’, the same information has been confirmed by two different senses

this suggests the same mind-independent object causes both perceptions from the different senses

CA: BERKELEY: it is futile to find resemblances through senses

eg the taste of an apple can not represent what it looks like, we simply know that an apple will be in our hands (visualising its shape) if we taste an apple because we have commonly experienced this

CCA: COCKBURN agrees with Berkeley that senses can not resemble one another but she argues the correlation in change between different senses proves the external world exists. eg if an object gets dented then our sight of the object and the feel of the object will change, the bigger the dent, the bigger the change in our sight of the object and the bigger the change in our feel of the object. the fact there is a regularity in the interrelation of our senses proves an external world exists.

what is the external world as best hypothesis counter argument?

RUSSELL: there is no way to be certain the external world exists but this is the easiest hypothesis to accept and understand

imagine you see a cat on the sofa, go to the living room, return and see the cat is on the floor

there are 2 options : either the cat exists independently of the mind and walked to the floor or the cat’s existence is dependent on the mind so stopped existing when you left the room and came back to existence when you returned

Russell argues the first option is better as it allows the two perception to have a connection and a reason for why the cat changed position

this idea is supported by KANT who argues there is no point in even thinking about the real world (noumenal world) since our perceived world (phenomenal world) is the world we inhabit and can speak meaningfully of

what is the criticism about scepticism about the nature of mind independent objects?

BERKELEY: the likeness principle:

indirect realism says we perceive mind dependent sense data that represents mind independent objects (which we can’t perceive)

if an invisible thing can’t be like a colour or an inaudible thing can’t be like a sound then a sensible thing (what we can perceive) can’t be like an insensible thing (what we can’t perceive)

so indirect realism is wrong to say mind dependent sense data can be like the mind independent world

CA: if the world was totally different to the one we perceive, we would not have been able to survive this long

CCA: can’t be certain that the best way for species to survive is to have a direct sense of the world

define noumenal world

the real world

define phenomenal world

the world we perceive

define idealism

there is no external world independent of the mind, something only exists if it is perceived, Berkeley called anything we perceive ideas and we perceive ideas directly

what are the arguments for idealism?

BERKELEY: attack on primary and secondary qualities

BERKELEY: the master argument

what is Berkeley’s attack on primary and secondary qualities?

when we perceive an object, we don’t perceive anything other than its primary and secondary qualities

everything we perceive is a primary or secondary quality

secondary qualities are mind dependent on the grounds they appear different from different perspectives eg heat feels different depending on if you were already hot or cold

then primary qualities are also mind dependent on the grounds that they appear different from different perspectives (perceptual variation) eg table looks like rectangle from above but a kite from the side

so everything we perceive is mind dependent

what is Berkeley’s master argument? and its counter argument?

presents as a conversation between Philonous and Hylas

Philonous: try think of an object that exists independently of being perceived

Hylas: ok i am thinking of a tree that is not being perceived by anyone

Philonous: that is impossible, you are still perceiving the tree

so we can’t conceive of mind independent objects because as soon as we try conceive of them they become mind dependent

so the existence of mind independent objects is impossible

CA: just because we can’t think of a mind independent object doesn’t mean it doesn’t exist, only proves you can’t have a mind independent thought

what are the issues with idealism?

illusion and hallucination

solipsism

problem with God

what is the issue with idealism based on illusions, dreams and hallucinations?

illusions, dreams and hallucinations all occur in our mind

if the whole world occurs in our mind, does this make illusions, dreams and hallucinations also real?

how do we distinguish them from what is real?

CA: BERKELEY claims that we can distinguish them based on our past and following experiences

eg if i know i have never teleported in the past because it is impossible, i know if i do teleport i am hallucinating or dreaming

if i see a pencil is bent in water but when i feel the pencil it is not bent, i know this was an illusion

what is the issue with idealism based on solipsism? and its counter argument?

if you can not conceive anything beyond your own mind, your own mind is the only mind which exists

so everyone you perceive is mind dependent and not real

CA: the universe is actually a permanent perception belonging to God

so what we perceive are copies of ideas that exist in God’s mind

so everyone is as real as you

what is Berkeley’s idea on the relation between God and the universe?

everything we perceive is mind dependent

there are three possible causes of these perceptions

the ideas

my own mind

another mind

can’t be ideas as they can not cause themselves

it can’t be my own mind as i would control what i see

so it must be another mind

this mind must be God as the perceptions are so complex, varied and ordered

so God permanently perceive the universe and what we perceive are copies of ideas that exist in God’s mind

what is the issue with idealism based on the problem with God?

if what we perceive are copies of God’s sensations and ideas then God must feel pain as we feel pain

but God does not feel pain as this would make him imperfect

so our sensations and ideas can not be copies of God’s ideas and sensations like idealism claims

CA: God is all powerful so he has the will to control what he perceives and what we perceive

CCA: proves he is not all loving to give us pain