Defending Common Defending Common SenseSense

Direct RealismDirect Realism

The trouble with sense-dataThe trouble with sense-data Key feature of Representative Realism and anti-realist Key feature of Representative Realism and anti-realist

theories. But…theories. But…

The object/appearance argument is mistaken.The object/appearance argument is mistaken.

2-D mental objects cannot resemble 3-D objects. 2-D mental objects cannot resemble 3-D objects. Only Only another three-dimensional sphere can another three-dimensional sphere can resembleresemble a sphere. a sphere.

Sense-data can just represent – but how to make sense of Sense-data can just represent – but how to make sense of this?this? For X to represent Y there needs to be a For X to represent Y there needs to be a representation scheme. With sense-data wrepresentation scheme. With sense-data we can’t know the e can’t know the representation scheme as we can’t compare reality to the representation scheme as we can’t compare reality to the representation.representation.

Scepticism - I am trapped behind a ‘veil of perception’. Scepticism - I am trapped behind a ‘veil of perception’.

Problems for anti-realism?Problems for anti-realism?

Where areWhere are theythey? They are mental entities. ? They are mental entities.

Mind is the brain - But you will not find any Mind is the brain - But you will not find any coloured two-dimensional objects in my brain.coloured two-dimensional objects in my brain.

If the mind is something distinct from the brain – If the mind is something distinct from the brain – a non-physical thing – then you do not have this a non-physical thing – then you do not have this problem. problem.

The Speckled Hen and the problem of The Speckled Hen and the problem of indeterminate sense-data. indeterminate sense-data.

Saving directness…Saving directness… The plausibility of direct realism can be supported The plausibility of direct realism can be supported

by the way it deals with the criticisms it faces. by the way it deals with the criticisms it faces.

In particular the problem of how error, In particular the problem of how error, misperception and illusion can occur.misperception and illusion can occur.

It is part of a common-sense realism to allow that It is part of a common-sense realism to allow that there can be variation in the way things look. there can be variation in the way things look.

But, The appeal to common-sense may just But, The appeal to common-sense may just appear to beg the question.appear to beg the question.

Perceptual states are belief statesPerceptual states are belief states or a mixture of belief states and sensations.or a mixture of belief states and sensations.

The problem of misperception or hallucinationThe problem of misperception or hallucination

becomes a species of the problem of false beliefs. becomes a species of the problem of false beliefs.

This is a general problem in epistemology,This is a general problem in epistemology, so the direct realist need notso the direct realist need not

feel any particular embarrassment whenfeel any particular embarrassment when confronted by the problem of misperception.confronted by the problem of misperception.

DisjunctivismDisjunctivism On the realist account there On the realist account there isis a difference a difference

between the experience of a person having a between the experience of a person having a veridical perceptual experience and one who is veridical perceptual experience and one who is having a non-veridical experience purportedly of having a non-veridical experience purportedly of the same object.the same object.

The nature of my true belief that there is a tree The nature of my true belief that there is a tree before me depends on it being about that tree.before me depends on it being about that tree.

The about-ness of the belief is tied essentially to The about-ness of the belief is tied essentially to the thing in the world. the thing in the world.

Even if the veridical and non-veridical Even if the veridical and non-veridical perceptual beliefs feel the same, there is perceptual beliefs feel the same, there is no ‘separable’ purely internal element no ‘separable’ purely internal element which the true belief shares with the false which the true belief shares with the false one.one.

They are different and so the problem of They are different and so the problem of hallucination need not arise.hallucination need not arise.

Analogy – Analogy – what internal features does the what internal features does the Mona Lisa share with a good fake? Mona Lisa share with a good fake?