Knowledge of The External World - Naive Realism

is the basic view that there is a world of physical objects, which exist as we perceive them. Our sensory ogans are reliable, and when we perceive a table for example, the table exists exactly as it appears to us.

Obviously there are occasions when our senses are deceived, possibly through illness or other external factors, but for the most part, our sensory organs are generally reliable and give us a realistic appreciation of what is actually out there.

Thomas Reid believed that common sense (sensus communis) is, or at least should be, the foundation of all philosophical inquiry. He disagreed with Hume, who asserted that we can never know what an external world consists of as our knowledge is limited to the ideas in the mind, and George Berkely, who asserted that the external world is merely idea in the mind. Reid claimed that the foundations upon which our sensus communis are built justify out belief that there is an external world. 

John Searle claimed that naive realism is continually shown to be true in the very nature of our actions. One example he gives, is of two people arranging to meet at a given place and time. his would no make sense if the people did not assume that "there is a place, in space and in time, that is independent of us, and we can meet at that particular time". That assumption is exactly was naive realism is.

On the surface naïve realism seems quite straightforward; we perceive things as they really are.  If I see a mug of tea, then I know that ‘there is a mug of tea’ because:

1. I see it (evidence)
2. I believe it because I see it (belief)
3. I see it because it is there (truth)

Unfortunately though, this is a circular argument.  In order for the above argument to be valid we require some additional external condition to justify point 3.

Although I believe that I can perceive the mug of tea as it really is, there exists a public space between the perceiver and the perceived object, and this could cause me to be mistaken, perhaps it is just a trick of the light, or my imagination.

Perceiver --------- PUBLIC SPACE --> Object

Two issues have been highlighted:

1. Failings of our senses e.g. optical illusions
2. Hallucinations

Both these problems have been responded to by Naïve Realists.

If something is red (a London bus in daylight) but you see it as khaki (at night

under street lamps) then, says the sceptic, you are having an experience of

something which is khaki, and what that something is cannot be identical with

the red surface of the bus. You might attempt to side-step the sceptic’s move

here by pointing out that you ‘know’ the bus is red ‘really’, and that you also

‘know’ that given the particular qualities of street lighting, it is perfectly

natural, and not illusory, to expect red colours to appear khaki. A camera

would record the same khaki shade, you might say, and cameras do not lie and

cannot be deceived because they do not make judgements or have perceptions. 

P.F. Strawson has argued that it is simply part of common-sense realism to allow for variations when we look at objects.  A piece of cloth, for example, may appear purple, but when observed in bright daylight, is clearly green.  He does not consider this to be a problem, we understand the differences, and allow for variations.  

Strawson also refers to blood, which is colourless when observed under a microscope, yet we think of blood as red.  There is nothing surprising about this; we are simply describing the world as it ‘looks’ to us.

If I see a bird in the distance and point out that it looks like a falcon, but when it gets closer I realise that it is not a falcon, but a kestrel, I am still seeing the same object.

I see the world as it is, and although I might make mistakes due to limitations, I recognise these limitations, and generally make allowances for them.

On the question of hallucinations, John McDowell argues that the account of a person suffering a hallucination is different from the account given by someone really observing an object. 

 Using the example of two people; one seeing a real tree, while the other hallucinating and seeing an imaginary tree, he admits that there is no difference on the inside, but from an external perspective, there is a great deal of difference. 

The difference, McDowell points out, is that in the hallucination, there is no tree in front of the perceiver, whilst in the case of the normal perceiver the tree is ‘present’ in his experience.

 McDowell refers to his view on hallucinations as an externalist approach

•  We perceive things in an unmediated way. This means directly – no third parties.
•  When our mind is subject to illusion, it is our mind that is at fault, not the object. There are problems when the messages are sent to our brain which makes things distorted.
•  Descartes dismisses singular occurrences of perpetual error by saying that – yes there are occurrences where we are mislead or deceived but with most things, everyday, but some things we can trust to be true(e.g. him sitting in a dressing gown by the fire holding a piece of paper). Singular occurrences of perceptual error are not enough to establish thorough scepticism.
•  Austin responds to Descartes’ argument from illusion. Basically, (using a church camouflaged as a barn as an example) we see something how it is affected, not out senses deceiving us. So with the church we are seeing not a camouflaged church (as it is) and not a barn (as it appears). Another example of this is a stick in water; it appears to be bent in water, but we see and know it is the water and refraction creating what looks like a bent stick. It is actually straight.

5.    

•    A veridical experience is a non-illusory experience which accurately captures reality. This is contrasted with a non-veridical experience. (E.g. those that occur in dreams and illusions) which fails to either accurately resemble reality or has no corresponding object in reality (e.g. hallucination).
• They can be identical to non-phenomenological experiences – this basically means that it’s possible for something veridical to be the same, feel the same, seem the same as a hallucination (phenomologically). (Macbeth – “is this a dagger I see before me? He felt it.)
•  Difference between perceptual variation and hallucination: variations in environment, our senses are not being deceived is perceptual variation. Hallucination = us being abnormal. Optical illusions, everyone can agree on (is constant) perceptual variations, everyone can see slightly different things