Indirect realism 25 marker

The immediate objects of perception are mind-dependent objects (sense data) that are caused by and represent mind-independent objects

Spearheaded by Locke’s empiricism

Scepticism =  doubting aspects of the external world

Solipsism = The rejection of the existence of everything except our own consciousness

• Indirect realism leads us down a rabbit hole to scepticism:

  • It claims that we do not perceive things in the world directly, we only perceive sense data

  • So all we know about the world comes from our mind-dependent senses, not from the mind-independent world itself. 

  • But as hume says, ‘the senses alone are not to be depended on’

  • PLUS due to Philosophy of Mind, I can’t confirm that others perceive what I perceive

  • I also can’t confirm that other minds exist

  • So we can doubt everything we know about the external world (scepticism) and we can doubt everything except our own consciousness (solipsism)

• Locke’s argument from the involuntary nature of our experience says that as we can’t control our perceptions, their causes must be external to our minds - an external world must exist 

  • Sense experiences are involuntary

  • e.g if you touch a flame, you cannot NOT feel pain/burn

  • So whatever causes our perceptions must be external to our minds

  • However, our complex reflections of memory and imagination somehow allow us to choose our experiences

• So Locke ‘proves’ there is an external world

• So Locke ‘proves’ there is an external world, but doesn’t prove that sense data is an accurate representation of the external world

• So sceptics can still argue that the external world could be completely different from what we perceive

• The idea that different senses often confirm information of each other

  • e.g. if I were to throw a ball to you, you would experience a range of sensations from your different senses which separately would confirm the sensations of other senses. You would be able to see the ball moving in space towards you. You might be able to hear it moving through the air, and you would be able to feel and smell it once you catch it.

  • So all your senses confirm that a ball is being thrown to you

  • So we can conclude that there is indeed a ball is being thrown to you

• Locke also uses ‘Molyneux’s Problem’ suggesting that a blind man would be able to distinguish a globe and cube by sight if his vision were to miraculously appear

  • This is because our senses cohere with each other and his other sense experiences would be consistent with the objects being a globe and a cube

  • They don’t exist in isolation 

  • So they give an accurate description of the world when combined

• Catharine Trotter Cockburn wrote to Locke, defending his ideas

  • Cockburn questions Berkeley's theory of perception and defends Locke by arguing that the combination of our sense experiences creates a cumulative case which offers us a coherent and consistent view of the external world

  • She argued that such coherence demonstrates that the external world is independent of the mind. 

  • She emphasises this point by considering a person with only one sense. Such a person would have such a limited experience of the external world that they might question its existence or even veer towards a conclusion of solipsism. 

  • However, with the additional senses we are provided with an ever more detailed and coherent perception of the external world.

  • Cockburn argues that our sense experiences are consistent (with one another) and regular. 

    • e.g Imagine you were blindfolded and given a dice to feel. Imagine also that you had never seen a dice before. It is highly likely that when the blindfold is removed the dice would look very similar to what you were expecting it to look like.

• So not only does the external world exist, it resembles what our perceptions show us

However we can’t actually prove that the world we perceive is the world as it really is so the resemblance theory is just the most likely explanation.

• Bertrand Russell provided a famous response to this problem of scepticism in his Problems of Philosophy.

• He considers the most common response to scepticism which can be written as follows:

  • P1. Because sense experiences are private to individuals it follows that no two people can actually experience exactly the same perceptions of the world. 

  • P2. Two people in the same place and at the same time can have identical perceptions of the world. 

  • P3. The best explanation is that there must be physical objects in the world which correspond to those perceptions. 

  • C. Therefore physical objects exist.

• Russell rejects his own argument 

  • Because he is producing an inductive posteriori argument, he must follow the rules of inductive a posteriori arguments. 

  • These rules tell us we can only reach probabilities about the objects of perception and so, he argues, he cannot actually prove the existence of other minds. 

  • This makes the above argument internally inconsistent.

  • (P2 doesn’t work because of the theory of mind plus P1 is wrong - we don't know that two people cannot experience the same thing)

  • PLUS according to leibniz law, Two people in the same place and at the same time cannot have identical perceptions of the world

• We cannot prove the existence of other minds due to the Philosophy of Mind

• As he couldn’t effectively defeat the sceptical argument he suggested that accepting the idea of a mind-independent external world was the ‘best hypothesis’

• Our experience of the world is made up of our perceptions received through sense experiences. 

• These perceptions are made up of sensations and reflections:

• sensations make up one category of knowledge/ideas - our senses convey into the mind several distinct perceptions of various external objects. They are more immediate than reflections

  • e.g. the taste of raspberries

• They are divisible into primary and secondary qualities

  • Primary qualities can’t be separated from objects of experience

  • They are more reliable than secondary ones

    • e.g. number, size, shape, hardness

  • Secondary qualities are properties of particular objects that produce sensations in us

  • They are less reliable than primary ones 

    • e.g colour, tase, temperature

• Our perception of secondary qualities like temperature or colour may vary 

• Our perception of primary qualities like shape are more certain

• Argues that the resemblance theory is inconsistent

• He agreed with Locke that the immediate objects of perception are ideas in the mind but goes on to argue that you cannot maintain the resemblance thesis (that our ideas of primary qualities resemble primary qualities)

  • The idea of resemblance only works if two things are said to be similar to each other

  • e.g. You can’t compare a sense of colour with a sense of smell, given their differences,

  • so how can we compare mental ideas and material qualities given that only the former can be perceived

  • An idea can only be like another idea - ‘I answer, an idea can be like nothing but an idea; a colour or figure can be nothing but another colour or figure’

• He’s guilty of epistemic hyperbole (Jonathan Jenkins Ichikawa) 

• Just because an idea might not resemble something mind dependent doesn’t mean it definitely doesn’t

Indirect realism, like direct realism, on a practical level makes more sense than other theories like idealism and more sceptical positions.

However, on a theoretical level, it seems to fail to the sceptical challenges presented and the criticism produced by Berkeley.