25 Marker; Indirect Realism Flashcards
Introduction on IDR
- IDR is a theory of perception which argues that the objects of perception are mind-dependent objects which are caused by and represent mind-independent objects.
ARGUMENT 1 - IDR leads to scepticism of mind-indp objects
-We perceive sense-data and sense-data are caused by a mind-indp reality.
-We ONLY know sense-data directly, therefore cannot prove the external world, therefore can’t know that sense-data are caused by mind-independent objects.
- VEIL OF PERCEPTION - external world can’t be accessed, therefore IDR can’t justify its claim that there is a mind-indp external world that causes our sense-data.
ARGUMENT 2 - Locke’s argument from the involuntary nature of our perceptions + TROTTER-COCKBURN
1) Locke argues that in perception we cannot avoid having certain sense-data produced in our minds, however if we turn from perception to imagination/memory then we can choose what we experience. THEREFORE, perceptual experiences must be produced in my mind by an exterior cause.
2) (ARGUMENT FROM THE COHERENCE OF VARIOUS SENSES)
Locke; different senses can confirm information (e.g, touching a fire to prove it exists)
Cockburn; one and the same object cause perceptual experiences through different senses e.g, hearing a dog bark vs seeing a dog.
THEREFORE< if mind-independent objects didn’t exist then we wouldn’t be able to infer from perceptual experiences of one sense which perceptual experiences we would have in another sense.
EVALUATION of Argument 2 (Trotter-Cockburn and Locke)
Perceptions could be caused by hallucinations where we have no awareness of control over - produce perceptions in our senses that cohere with one another, THEREFORE Locke and Trotter-Cockburn cannot fully escape scepticism.
ARGUMENT 3; Russell’s Best Hypothesis
- Response to scepticism
- P1) Physical objects exist and cause my sense-data, or they do not
P2) We can’t prove either claim, therefore we treat them as hypotheses
P3) The hypothesis that physical objects exist and cause my sense data is BETTER, therefore physical objects exist and cause my sense-data. - he concludes that this is the best hypothesis as we cannot prove its existence or lack thereof - he uses an abductive approach so thus we are justified in trusting our perceptions caused by a mind-indp external world.
EVALUATION of argument 3 (Russell’s Best Hypothesis)
Ockham’s Razor; a mind-indp reality existing has more explanatory power than other possible explanations, thus we can claim it as the ‘best’ hypothesis.
Although it doesn’t defeat scepticism, it offers to rid doubt beyond human incredulity.
ARGUMENT 4; Berkeley’s criticism that mind-dependent objects cannot be like mind-independent objects.
-IDR claims that sense-data represents mind-independent objects. However, Berkeley responds that for something to be LIKE or resemble something, then they must be alike
-How is it possible that something unexperienced (mind-indp object) can be like something experienced (mind-dependent object)?
-LIKENESS PRINCIPLE; there is nothing like a perceptual experiences except another perceptual experience, THEREFORE, we cannot say that our senses-data resembles physical objects.
ARGUMENT 5; Lock’es distinction of primary and secondary qualities
-‘Quality’ = a power that a physical object has to produce an idea in a mind.
- A primary quality is ‘in and of’ the object itself, and is inseparable from the object no matter what change happens (mass, shape, motion)
- A secondary quality is a quality that produces various sensations (colour, sound, taste) - Locke argues that it is experienced by the definition of a perceived.
Secondary qualities are the result of primary qualities.
EVALUATION of argument 4/5 (Berkeley and Locke on primary/secondary qualities)
- Locke defends IDR - we distinguish the qualities we perceive.
- Berkeley argues that if we have no experience of mind-indp objects then we can’t know our perceptions (sense-data) resemble them.
