theories of perception + scepticism 3 and 5 markers

Question 1

define direct realism (3)

Answer 1

direct realism is a theory of perception that makes two key claims: (a) an external world of mind-independent objects and their properties exist and (b) we perceive it directly. e.g:
- the immediate objects of perception are mind-independent objects and their properties
- we directly perceive mind-independent physical objects in the external world

Question 2

what is an illusion (3)

Answer 2

an illusion is to do with perceiving a property in an object when an object does not have that property e.g a bent stick that is actually straight

Question 3

what is a hallucination (3)

Answer 3

hallucinations are perceiving an object when there is none e.g to see a pink elephant when there is no pink elephant in reality

Question 4

what is the difference between an illusion and a hallucination (3

Answer 4

an illusion is to do with perceiving a property in an object when an object does not have that property e.g a bent stick that is actually straight
hallucinations are perceiving an object when there is none e.g to see a pink elephant when there is no pink elephant in reality

Question 5

outline the argument of illusion against direct realism (5)

Answer 5

1. in an illusion i perceive something to have the property F
2. according to DR, if i perceive something to have the property F, something must have the property F
3. in an illusion, the real physical object does not have the property F
4. illusions are subjectively indistinguishable from veridical perceptions
5. therefore, i must be perceiving the same thing, sense data, in both illusions and veridical perceptions
6. therefore, in all cases, the immediate objects of my perception are sense data = direct realism is false

Question 6

outline the argument from perceptual variation against direct realism (5)

Answer 6

1. there are variations in perception
2. our perception varies without corresponding changes in the physical objects we perceive (e.g desk remains rectangular even though it changes from different angles)
3. therefore, the properties physical objects have and the properties they appear to have are not identical
4. therefore, what we are immediately aware of in our perceptions is not exactly the same as what exists independently of our mind

Question 7

outline the argument of hallucination against direct realism (5)

Answer 7

1. in a hallucination, we perceive something having some property F
2. perceiving something as having property F means that there is something that has this property
3. we dont perceive a physical object at all (unlike the case of illusion)
4. therefore, what we perceive must be mental - sense data
5. hallucinations can be experiences that are subjectively indistinguishable from veridical perception
6. therefore, we see the same thing, sense data, in both hallucinations and veridical perceptions
7. therefore, in all cases we see sense data and not physical objects immediately = direct realism is false

Question 8

outline the time lag argument against direct realism (5)

Answer 8

1. it takes time for light to reach our eyes from the object we are perceiving (e.g it takes 8 minutes for the light from the sun to reach us)
2. during that time the object may have (a) changed (b) ceased to exist
3. therefore, the object of my immediate experience is distinct from the originally mentioned object because (a) it may have different properties or (b) because you can’t perceive something that doesn’t exist
4. therefore, the immediate object of our visual experience is not identical to the object being seen = direct realism is false

Question 9

outline the direct realist response to the argument from illusion (5)

Answer 9

• relational properties: when the pencil in water looks crooked, there is nothing that is crooked. the pencil has the property of looking crooked
• sometimes we perceive the ‘looks’ properties of physical objects, sometimes we experience the properties they have that don’t relate to how they are perceived,
  – in both cases we directly perceive physical objects and their properties

Question 10

outline the direct realist response to the argument from perceptual variation (5)

Answer 10

• in perception we can be aware of a range of properties, some which the object has independent of our minds, and some of which it has in relation to being perceived.
• the colour of the table (brown) is the colour it appears to have when seen by normal observers under normal conditions - this is what it means to talk of colour, we don’t always see what colour is, but when we see its (normal) colour, we see the table and its properties
• likewise with shape: it’s rectangular, even if it doesn’t always look rectangulat

Question 11

outline the direct realist response to the argument from hallucination (5)

Answer 11

—disjunctive theory of perception:
1. either i directly perceive a mind-independent physical object that is F
2. or it appears to me just as if there is something that is F, but there is nothing that is F

• hallucinations and veridical perceptions are two completely different kinds of mental states- they can seem exactly the same but that doesnt prove they are the same.
• hallucinations tell us nothing about perception, e.g in a hallucination, we don’t perceive anything, we imagine it,
  — therefore, the argument from hallucination is no objection to direct realism

Question 12

outline the direct realist response to the time lag argument (5)

Answer 12

• what is said to be perceived here is itself physical, e.g lightwaves
• there is a confusion between what we perceive and how we perceive

– example of seeing light on lakes and paper, to see the light reflecting of the paper is just seeing the paper
- the time lag argument only shows that we literally perceive the past

Question 13

define indirect realism (3)

Answer 13

the immediate objects of perception are mind-dependent objects (sense data) that are caused by and represent mind-independent objects

—-We perceive physical objects, which exist independently of the mind, indirectly via sense-data which are caused by and represent physical objects.

Question 14

define primary qualities (3)

Answer 14

• properties of objects that are independent of any observer e.g solidity, motion, weight
• exist in the thing itself
• do not rely on subjective judgements
  —e.g if a ball is round, no one can argue it is a triangle

Question 15

define secondary qualities (3)

Answer 15

• properties that produce sensations in observers e.g colour, taste, smell
• does not provide objective facts about things
• can be described as the effect objects have on people

Question 16

what are sense data (3)

Answer 16

mind dependent objects of perception are caused by and represent mind-independent objects and their properties.

Question 17

explain the distinction between primary and secondary qualities (5)

Answer 17

• primary qualities are those properties of an object that are not related by definition to perceivers. for example, shape, motion, weight. it is the idea that the physical object has these properties in and of itself, and so Locke observes that they’re inseparable from a physical object. they are also mind independent.
• however, secondary qualities are mind dependent. with secondary properties, they are nothing in the objects themselves, but have the power to produce sensations in observers.
  primary = objective
  secondary = subjective

Question 18

outline how indirect realism leads to scepticism about the existence of mind-independent objects (5)

Answer 18

• indirect realism is the claim that:
  1. mind-independent/physical objects exist in the external world
  2. but we never directly perceive them
  3. instead we only ever perceive them indirectly by directly perceiving or being aware of mind-dependent entities
• if we never directly perceive mind-independent/physical objects, our perceptual experiences can never give us direct evidence that such objects exist
• any claim that mind-independent objects exist would therefore have to be inferred from such claims about our sense-data
• such an inference cannot be justified
• neither experience (a posteriori) nor reason (a priori) can justify such an inference
• therefore, the indirect realist cannot know that there is any mind-independent/external reality beyond what is directly perceived

Question 19

outline how indirect realism leads to scepticism about the existence of mind-independent objects and explain Locke’s response based on the involuntary nature of our experience (12)

Answer 19

• if we never directly perceive mind-independent/physical objects, our perceptual experiences can never give us direct evidence that such objects exist
• any claim that mind-independent objects exist would therefore have to be inferred from such claims about our sense-data
• such an inference cannot be justified
• neither experience (a posteriori) nor reason (a priori) can justify such an inference
• therefore, the indirect realist cannot know that there is any mind-independent/external reality beyond what is directly perceived

involuntary nature of experience:
* sensations must be caused by something outside ourselves
* the fact that our experiences are involuntary suggests they must come from outside ourselves, and are most likely caused by mind-independent physical objects, since the ideas that are mind-dependent and stem from our own imagination are under our control and voluntary. - lockes example of shutting eyes and choosing to recall the idea of light
* e.g not being able to choose a particular experience you have when you taste something

Question 20

outline how indirect realism leads to scepticism about the existence of mind-independent objects and explain Locke and Cockburn’s response from the coherence of various kinds of experience (12)

Answer 20

• if we never directly perceive mind-independent/physical objects, our perceptual experiences can never give us direct evidence that such objects exist
• any claim that mind-independent objects exist would therefore have to be inferred from such claims about our sense-data
• such an inference cannot be justified
• neither experience (a posteriori) nor reason (a priori) can justify such an inference
• therefore, the indirect realist cannot know that there is any mind-independent/external reality beyond what is directly perceived

coherence of the senses:
* our senses tend to confirm and mutually support one another. we can touch what we see to verify that what we see really exists.
* cockburn: we can predict a sensory experience, e.g a sound based on an experience from a different sense, e.g what we see
* the existence of a mind-independent world is the best explanation for why our experiences are involuntary and why they cohere with one another

Question 21

outline the argument from Berkeley that we cannot know the nature of mind-independent objects because mind-dependent ideas cannot be like mind-independent objects (5)

Answer 21

we cannot know the nature of mind-independent objects because mind-dependent ideas cannot be like mind-independent objects. Ideas can only resemble other ideas, so our ideas cannot inform us of a mind-independent external world of material objects (and their properties)

Question 22

define idealism (3)

Answer 22

the immediate objects of perception (i.e ordinary objects such as tables, chairs, etc) are mind-dependent objects

Question 23

explain Berkeley’s attack on the primary secondary distinction (5)

Answer 23

• secondary qualities are inseparable from primary qualities: colours and shape are inseparable, as you fill a shape up with a colour: the shape is the boundary of the colour
• since my perception of shape and size depend on the position of my eyes, my experience of solidity depends upon my sense of touch, and my idea of motion is always relative to my own situation
  – locke was mistaken about primary qualities: all sensible qualities are just ideas in the mind

Question 24

explain the master argument (5)

Answer 24

• the master argument is in favour of idealism which is the theory that immediate objects of perception are mind dependent objects and only mind dependent objects exist
• it is against the theory of perceptual realism which is the theory that there are objects that exist mind independently
  the master argument suggests that it is a contradiction to say that one can conceive of a mind independent object as that object would only exist and rely on the perceiving persons mind
• e.g. Philonous argues that if Hylas conceives of a tree existing by itself, (independently and unperceived) then the tree is dependent on Hylas’ perceiving mind

Question 25

explain why illusions pose a problem for idealism (5)

Answer 25

– key issue: how does it differentiate between veridical and non-veridical perceptions
- because there is no distinction between appearance and reality, everything we experience, for the idealist is real. therefore, the experience of a bent stick in water is a bundle of ideas in the same way that a straight stick is.

Question 26

explain why hallucinations pose a problem for idealism (5)

Answer 26

– key issue: how does it differentiate between veridical and non-veridical perceptions
- because there is no distinction between appearance and reality, everything we experience, for the idealist is real. therefore, the experience of a pink elephant in the room is a bundle of ideas in the same way reality is

Question 27

what is the difference between global and local scepticism (3)

Answer 27

Global:
- the view that it is impossible to have knowledge, that it’s impossible for human beings to know anything at all
- it is : withholding assent: it is impossible to know anything to be either true or false.
- it is universal

Local:
questions or doubts the possibility of certain types of knowledge

Question 28

explain why idealism leads to solipsism (5)

Answer 28

• solipsism is the belief that the only thing i can be certain of is my own mind
• i dont know that other minds exist because i cannot perceive them
• although my immediate perceptions can’t be doubted, any inferences i make with regard to an external source can be doubted
• this could lead to the conclusion that the only thing that exists is my mind and everything else is a product of my mind
  —- berkeley argues that we can only have knowledge of our own minds and their ideas

Question 29

explain why the role played by god poses a problem for idealism (5)

Answer 29

• if we can only know our experiences then how can we know god.
• god is not one of our experiences and therefore we cannot know him empirically.
• even if we do know that there is a god, then this is something other than sense-experience
• therefore, we can know something other than sense-experiences
• if we can know something other than sense-experiences (god), why can’t we be living in a world of independently existing physical objects as the causes of our sense-experiences: by introducing god into the equation, berkeley has undermined his own argument that we can only have knowledge of our experiences

+ is god himself a perceiver? - means god has perceptual experiences in the same way that i do
- if that’s the case, god cannot be unchanging because he is acquiring ideas. god being a perceiver would also involve god experiencing pleasure and pain
— goes against the traditional idea of god as eternal and immutable

Question 30

explain berkeley’s response to the argument from illusion (5)

Answer 30

• idealists respond to this with reference to the regularity of our experiences: we consider to be real whatever fits in with past experiences
• anything that doesn’t fit in with or contradicts regular past experiences could be considered a perceptual error
  e.g

Question 31

explain berkeley’s response to the argument from hallucination (5)

Answer 31

• idealists respond to this with reference to the regularity of our experiences: we consider to be real whatever fits in with past experiences
• anything that doesn’t fit in with or contradicts regular past experiences could be considered a perceptual error
  e.g…

Question 32

explain berkeley’s response to the problem posed by the role of god (5)

Answer 32

• we cannot disclaim the view that god creates the ideas in our minds on the basis that we can’t perceive god. the order of my ideas, their regularity, their coherence can only be explained by god. he also adds that god doesn’t perceive or experience sensations but that those sensations exist in his understanding. god wills me to have sensations and he makes ideas perceptible to my mind. that means he is still unchanging (immutable) and berkeley’s argument is not contradictory in relation to the traditional attributes of god.

Question 33

what is philosophical scepticism (3)

Answer 33

• considers wider grounds. doesnt doubt specific types of propositions or knowledge claims
• considers a class of propositions (e.g based on reason, based on experience, or propositions concerned with the existence of God) and applies the same doubt to all members of that class of propositions, not just one

Question 34

what is normal incredulity? (3)

Answer 34

• refers to everyday cases of doubt e.g eating crisps from a bowl and not believing they’re prawn cocktail despite the packet next to it.
• cases of normal doubt arise when we think we fail to have knowledge.
• happens when we encounter ordinary evidence which challenges a belief or makes it appear unlikely
• can be overcome if the grounds for doubt are removed

Question 35

what is the difference between philosophical doubt and normal incredulity (3)

Answer 35

Philosophical scepticism:
- considers wider grounds. doesnt doubt specific types of propositions or knowledge claims
- considers a class of propositions (e.g based on reason, based on experience, or propositions concerned with the existence of God) and applies the same doubt to all members of that class of propositions, not just one

Normal incredulity:
- refers to everyday cases of doubt e.g eating crisps from a bowl and not believing they’re prawn cocktail despite the packet next to it.
- cases of normal doubt arise when we think we fail to have knowledge.
- happens when we encounter ordinary evidence which challenges a belief or makes it appear unlikely
- can be overcome if the grounds for doubt are removed

Question 36

what is global scepticism (3)

Answer 36

• the view that it is impossible to have knowledge, that it’s impossible for human beings to know anything at all
• it is : withholding assent: it is impossible to know anything to be either true or false.
• it is universal

Question 37

what is local scepticism (3)

Answer 37

questions or doubts the possibility of certain types of knowledge