part three - immediate objects of perception Flashcards
Intuition
A simple act of mental vision. Discovering the truth of a claim through thinking.
Deduction
Valid inferences from premises to conclusion. Reasoning.
Inductive and Deductive Arguments
Inductive - the truth of the premises makes the conclusion probable, doesn’t guarantee it
(generally involves a particular case)
Deductive - the truth of the premises would guarantee the truth of the conclusion
Mind-Independent
the quality exists in the object.
objects don’t depend on minds for their existence.
L has a property of Y
Lemons are yellow
Mind-Dependent
there must be a mind for the object to exist.
Objects depend on a mind to exist.
L has a property of T to someone
Lemons are tasty to Ella
Direct Realism
the view that we’re immediately aware of a world of mind-independent objects and their properties
Indirect Realism
the view that we indirectly perceive physical objects, which exists independently of our minds via sense data
Sense Data
non-physical, private, mind-dependent mental images which are caused by and represent physical objects
Idealism
the view that we are immediately aware of mind-dependent objects, and there are NO mind-independent objects
Four Issues For Direct Realism
argument from perceptual variation (Russell)
argument from hallucination
argument from illusion
time-lag argument
Argument From Perceptual Variation (Russell)
Issues For Direct Realism
- The object I’m directly aware of (e.g a table) is changing (=the phenomena of perceptual variation)
- The real, external object isn’t changing during this time
- I am not directly aware of the real, external object.
Argument From Perceptual Variation (Russell) - Responses
Issues For Direct Realism
- premise one asserts the existence of a changing object which we’re immediately aware. It’s precisely the existence of such an object Russell is trying to prove (he uses intended conclusion as one of his premises)
- the phenomena of perceptual variation can be explained without recourse to sense date. The property of appearing brighter under certain lighting conditions can be explained in terms of relational properties. The table really does appear lighter when it stands in just that relationship to the perceiver.
Argument From Hallucination
Issues For Direct Realism
- In perception we are aware of objects
- In cases of hallucination, we aren;t aware of mind-independent objects
- The objects of awareness in perception and hallucination are the same
- Therefore, in both perception and hallucination, we aren’t aware of mind-dependent objects
Argument From Hallucination - Responses
Issues For Direct Realism
why should we accept that ‘the objects of awareness in perception and hallucination are the same’ (premise three) this disjunctive account of perception tries to distance perception and hallucination. On that account, when I have a certain experience I am either directly aware of it (=perception) or having an hallucination (=an alternative mental state)
aren’t hallucinations more like dreams than they are perceptions?
hallucinations are obvious to distinguish between reality as they are exaggerated perceptions of the truth
Time-Lag Argument
Issues For Direct Realism
2012 - photo of a Galaxy over 13 billion light years away, image captures the appearance of the galaxy 500 million years after the big bang and it’s very likely the galaxy doesn’t exist anymore. Were we to study the night sky we wouldn’t be aware that some of it no longer exists, we must in fact be aware of something else.
Time-Lag Argument - Responses
Issues For Direct Realism
we perceive objects as they were. With respect to our conscious lives, we’re always living in the past.
Argument From Illusion
Issues with Direct Realism
(for - immediately aware of sense data)
- During illusions, it appears to you that something is X
- If it appears to you that something is X, then you must immediately perceive something which is X (the phenomenal principle)
conclusion one - So you immediately perceive something that is X - There’s no suitable mind-independent object that is X
conclusion two - during illusions, the thing you immediately perceive is not a mind-dependent object
conclusion three - during illusions, the thing you perceive is a mind-dependent object - Illusions are subjectively indistinguishable from veridical experiences
- Subjectively indistinguishable experiences must involve immediate perception of the same kind of object.
conclusion four - you immediately perceive mind-dependent objects in veridical experiences
conclusion five - direct realism is false (= we are immediately aware of sense data)
Argument From Illusion - Responses
Issues For Direct Realism
- the phenomena can be explained in terms of relational properties, The spatial relationship between the perceiver and the image explains the appearance.
- the argument can be challenged in terms of the truth of premise one -‘during illusions, it appears to you that something is X’ so even if the inference is valid, the argument isn’t sound
- exaggerated perception of reality
Indirect Realists
Russell and Locke
Idealist
Berkeley
Indirect Realism - Criticisms
scepticism about the existence of the external world
scepticism about the nature of the world
causal problem
berkeley - representation problem
The Causal Problem
Indirect Realism - Criticism
how can physical objects cause non-physical sense data to exist? For the process of cause and effect to take place, there must be a causal nexus (a point of contact) whereby the cause brought the effect into existence. However, there cannot be a causal nexus between something physical and non-physical.
Berkeley - Representation Problem
Indirect Realism - Criticism
how can mind-dependent objects possibly represent mind-independent objects? Berkeley develops this by pointing out that sense data and physical objects are significantly dissimilar; for example physical objects endure whereas sense data are fleeting
Scepticism About the Nature of the World
Indirect Realism - Criticism
if indirect realism is accurate, and all of our judgment about mind-independent objects are based on sense data, how can we know that our perceptions accurately represent the mind-independent objects existing in the world? Our perception of the world could bear no resemblance to the physical world whatsoever
Scepticism About the Nature of the World - Russell’s Response
Indirect Realism -Supporting Response
Russell argues that while we can’t know the nature of the objects themselves, we can know ‘relations between objects’ aka we can know that whatever is responsible for my sense datum of the glass is on top of whatever is responsible for my sense datum of the table. This means that we can at least be justified in our beliefs about the relations between mind-independent objects.
Scepticism About the Nature of the World - Locke’s Response
Indirect Realism - Supporting Response (Primary and Secondary Quality Distinction)
Locke introduces the distinction between primary and secondary qualities. Primary qualities exist in the object as they’re perceived, and are inseparable from the object. Examples include solidity extension and figure. Secondary qualities are produced by primary qualities, and are powers of objects to produce sense data in us. Examples include colour, sound and taste. For example, if I look at light and see yellow, the light doesn’t possess yellowness, only the power to produce the idea of yellow in me. Locke claims that we can be justified in our beliefs about nature of primary qualities, even if we have to concede we don’t know about the secondary qualities of the object.
Scepticism About the Existence of the External World
Indirect Realism - Criticism
if indirect realism is accurate, and all of our judgments about mind-independent objects are based on sense data, how can we know that mind-independent objects even exist? We could be perceiving a world of sense data, without any physical objects existing
Scepticism About the Existence of the External World - Russell’s Response
Indirect Realism - Supporting Response to Criticism
Russell argues that the existence of mind-independent objects is the best hypothesis for the existence of sense data. Inference to the best explanation is a widely deployed method of argument, which in this case allows us to make sense of the existence and regularity of sense data.
Scepticism About the Existence of the External World - Locke’s Responses
Indirect Realism - Supporting Response to Criticism
Locke argues that as some of our perceptions are involuntary (we can’t chose what we perceive) our minds can’t be the cause of our perceptions.
Locke also argues that our perceptions of mind-independent objects exhibit a coherence not found in, say hallucinations. I can see the object, smell it, touch it and taste it, which is evidence enough to assert that the object really exists.
Relativity
Berkeley’s Attack on the Primary and Secondary Quality Destinction (Locke) - For Idealism
Just as perception of secondary qualities is relative to the perceiver, so is primary.
example - a mouse would think of a cat as big but a human would think of a cat as small. Therefore size is a mind-dependent quality, in fact all primary and secondary qualities are mind-dependent.
Response - big and small aren’t true measures of size - in either case the cat is 30cm tall for example
