Criticism of naïve realism on the grounds of our sensory weaknesses caused John Locke to divide the qualities of objects into two categories. Primary qualities include such things as extension, location, shape and number, whereas secondary qualities would include colour, smell and taste.
Locke states that objects exist in their own right, and possess primary qualities that are objective and can be measured clearly, and would, under normal circumstances, be generally agreed upon.
Secondary qualities however, are much more subjective and exist only as sense impressions. For representative realists, the qualities in objects that produce primary qualities are real, and exist independently of us; however secondary qualities exist only as ideas in those who perceive them.
“Human understanding is like a closet wholly shut from light, with only some little openings left, to let in external visible resemblances, or ideas of things without” (Essay Concerning Human Understanding 1690)
Locke’s ideas are still based on an external world that is real, but rather than consider a ‘direct realism’ in the way that naïve realists do, he considers that we only indirectly view the external world. His ‘indirect realism’ has become known today as Representative Realism, because, due to the limitations of our senses, we are not seeing objects as they really are, we are only seeing representations of them.
The basic principle:
When we look at an object, we are not seeing anything solid, we are merely receiving sense data – information which we translate into images within our brain.
Examples of different views:
· A hears a human cry, B hears a barking fox
· A thinks Phenol-thio-urea tasteless, while B pulls a face and declares it to be bitter
· A finds the smell of his oil paints to be sweet and fruity, while B finds it nauseating
· A comes in from the cold and declares the house to be warm as toast, while B, at home for hours, says it is freezing
· A hears an ascending and descending note as B drives her racing car by him, while B only hears a constant note.
A has a sort of space helmet over his head. Let’s suppose he has just landed on Zardoc 111 about which as yet nothing is known. Whatever the nature of Zardoc’s surface, it is going to be assessed by A through his helmet and suit.
He cannot have direct contact with the surface of the planet. Suppose, by analogy then, we regard his helmet and suit, or at least, the inner surfaces of them, as his percepts, and whatever lies beyond his suit as the real Zardoc.
A can never compare his perception of Zardoc with the real Zardoc because hecan never take his helmet off. He cannot compare colours, smells, textures,shapes or anything else, nor say whether his helmet distorts the colours of theplanet, nor even that the planet has colour. He is locked inside his suit of sensesand therefore cannot have confidence in his assessments of the surface featuresof the planet, because his suit could fundamentally distort what he is assessing.
This then is the sort of position we now find ourselves in with indirect realism.
Locke considered that a tomato, for example, has certain true, or primary qualities, such as size and shape – these are distinct in that our sensory experience of them resembles them in reality, we are directly aware of the way the atoms of the tomato are arranged.
At the same time though, other qualities of the tomato, such as its colour, smell or taste, are only of a secondary nature due to the interaction of various factors, for example, when one sees a tomato as red, the sensation of seeing redness is not produced by some quality of redness in the object, but by the arrangement of atoms on the surface of the object which reflects and absorbs light in a particular way..
These secondary qualities depend on environmental conditions in conjunction with our own sensory system, and explains why different people might disagree over how it might appear to them.
Locke is not disputing that a tomato, for example, has a particular colour, smell and taste, he is simply stating that we might not be perceiving those qualities exactly as they really are.
Presumably dogs only see the world in black and white due to the limitations of their optical nerves, but as they do not know any difference, the world is black and white to them.
This does highlight one potential difficulty with representative realism, in that, if we only have knowledge of representations of the world, how can we know that they resemble in any significant way the objects to which they are supposed to correspond? How do we know for certain that the colour, smell and taste of a tomato is at all like the way that we perceive it?
For a representative realist, we are not perceiving the object directly, what we are perceiving is information which is fed into our brain through our sense organs, or to put it simply, we are perceiving sense data.
Bertrand Russell used the example of the sun to emphasise how we do not perceive the actual objects, merely their sense data. He pointed out that it takes eight minutes for the sun’s light to reach us, so when we look at the sun, what we are actually seeing is the sun of eight minutes ago. It would therefore be possible to “see the sun” even though it might have exploded and ceased to exist five minutes ago.
- Berkeley – a tiny insect would consider its foot as being quite large, however, to a human being it is incredibly small. Considers that extension is not ‘inherent within that object’ otherwise its size would be viewed the same by all who perceived it
- Berkely – Locke’s closet – holed up in his closet, Locke would never be in a position to check whether his supposed ‘resemblances or idea of things without’ actually resembled the external world itself. He would never be able to lift the veil and look on the other side, so he’s trapped in a world of representations. He even went as far to say that rather than tear through the veil, there is, in fact, nothing behind it to reconnect with. To Berkeley, reality consists in the ideas or sensations themselves.
- If what we are perceiving are our own personal representations of the world, we do not know what the real world is like, and thus make comparisons. Maybe we are perceiving the world as it is
- Therefore, if we have an hallucination, who is to say that that object we are seeing isn’t actually there