Perception As A Source Of Knowledge - Direct Realism Flashcards
Define direct realism
Physical objects exist independently of our minds and of our perceptions of them and the immediate objects of perception are mind-independent objects and their properties.
List the main arguments against direct realism.
- perceptual variation
- argument from illusion
- argument from hallucination
- time lag argument
Perceptual variation argument
Russell (an indirect realist) argued that what we perceive is not the same as what is in reality, so direct realism is false.
(He uses the example of the table)
Russell’s table example (argument from perceptual variation)
Russell points to the example of a shiny brown table.
He argues that the colour of the table actually depends on where you stand in relation to it.
There is light falling onto the table making a part of it shiny and therefore white and colour in certain sports
But if another person stands at a different spot, the white spot would appear to them on a different part of the table.
Therefore, where one person sees white the other person sees a brown spot.
-> A particular spot cannot be two colours at once, therefore colour cannot be a property of the table.
This can also be applied to texture (under a microscope) and shape from (various angles.)
Direct realist response to the perception variation argument
Direct realists can respond by refining the theory and introducing the idea of
‘ relational properties’.
What is a relational property?
A relational property is one that varies in relation to something else.
For example, being north of something, is a real and mind independent property that something can have – but varies relative to the other object.
How do relational properties relate to Russell’s table example?
The table has the ( mind independent ) relational property of appearing kite – shaped relative to certain perceivers, whilst simultaneously having the (mind independent) relational property of appearing square shape to another perceiver.
—> the table has both these mind independent properties, but which you perceived depends on where you are.
NB. the object doesn’t change, but the perceiver does.
Argument from illusion
Indirect realists argue that we have seen the appearance/reality distinction challenge direct realism, so we can appeal to illusions to press the case.
Illusions can be ‘ subjectively indistinguishable’ from vertical perception, yet do not reflect what is in reality, this provides an argument against direct realism.
Argument from illusion using the crooked pencil example, formally stated.
P1) we perceived something having some property F (e.g. a pencil that is crooked)
P2) when we perceive something as having property F, then there is something that is F (something we see as F)
P3) in an illusion, the physical object does not have the property F (the pencil is not crooked.)
C1) therefore, in illusions, what has the property F is something mental, sense date
C2) therefore, in illusions, we see data, and not physical objects immediately
P4) illusions can be ‘ subjective distinguishable vertical perception’
C3) therefore, we see the same thing, namely, in both illusions and vertical perception
C4) therefore in all cases we see and data, and physical objects immediately
C5) therefore directrealism is false.
Direct realist response to argument from illusion
Direct realism can give the same response as before the pencil in the water looks crooked, there is nothing that is crooked.
P2 is wrong, P2 says that if we perceive something as having property F, then there is something that is F.
Instead, the pencil has the property of looking crooked when half submerged water.
There is a difference between the property ‘being crooked’ and the relational property of ‘looking crooked.’
(Usually of course, something that looks crooked is crooked. But the two properties can come apart, and something can look crooked when it is straight)
—> we still directly perceive physical objects and their properties.
Argument from hallucination formally stated
P1) in hallucination, we perceive something as having property F
P2) when we perceive something is having property F, then there is something that is F
P3) in a hallucination, we don’t perceive physical objects at all
C1) therefore, what we perceive must be mental
P4) hallucinations can be experiences that are ‘subjectively distinguishable’ from veridical perceptions
C2 therefore, we see the same thing, namely sense data in both hallucinations and veridical perceptions
C3) therefore, in all cases, we see data, and not physical objects immediately.
C4) therefore direct realism is false.
Direct realist response to argument from hallucination
Disjunctive theory of perception.
According to the disjunctive theory of perception, hallucinations and veridical perceptions are two completely different kinds of mental state, because hallucinations, the person isn’t connected to the world.
To imagine something is not to perceive something mental such as sense data, but not to perceive anything at all. Perception is a relation of the subject to the world forming a cognitive contact which hallucinations are not.
Own opinion on response to hallucination objection
To me this feels too easy and there is also the problem of if we are allowing the idea of my generated believed perceptions how can we tell what’s reality and what is a hallucination?
Direct claim that there is a noticeable difference between these two states of mind however this is not a particularly strong rebuttal
E.g. schizophrenia can go unnoticed until the hallucinations becomes so absurd that they are noticed by other people
Presents problem for direct realism
Rectify this issue and condition of a requirement for objects to be seen and perceived by other people as well as the perceiver themselves to confirm its authenticity.
Timelag argument
It takes time for light waves or sound waves or smell to get from the physical objects to our sense organs. Therefore we could argue we are not directly perceiving things.
Direct realist replied to the timelag argument
Direct realist can reply by saying that this is a confusion between how we perceive and what we perceive.
Compare these two pairs of questions:
1. Can you see the lake? And can you see the light reflecting of the lake?
2. Can you see the paper and can you see the light reflecting from the paper?
In the first case we can turn our attention from the actual lake and the light actually reflecting off it but in the second case there is no difference in what we are supposed to see. To see the light that the paper reflect is just to see the paper.
So direct realism can argue, except in special conditions, we don’t perceive light waves directly and physical objects indirectly light waves are part of the story of physical objects.
Thus, the time lag arguement is in the nature of perception itself, we can only ever see the world as a moment before, but this does not equate to it being indirect.
