Category: representational realism

It’s been a long weekend. And time is subject to perceptual variation. So bang on time is the promised homework.

The following four questions / tasks (the bullet pointed bits) MUST be done (even if you’re called Jake) by Monday 22nd February.

Seeing as you’re getting so good, have a go at these. They will require some thought, I had to think about them, but that means little as I have fewer brain cells than you.

  • What does a comparison of idealism and direct realism tell us about the difference between epistemology and ontology?
  • Why does solipsism threaten both idealism and representative realism? What philosopher(s) might we turn to for an escape from solipsism and how might he help us?

These are from the text book, p. 60, but are rather good: (I’ve got a bit of a hunch about Locke and primary / secondary qualities being in the exam – It is only a hunch and not inside information – unfortunately).

  • Say whether the following are examples of primary qualities, secondary qualities, both, or neither. Explain your thinking.

  • Describe and illustrate one epistemological distinction between primary secondary qualities and one ontological one.


Bertrand Russell proposed a system of representative realism based on the notion of ‘sense data’. ‘Sense data’ are the products of our perception of the world: our senses produce ‘sense data’ as a response to our encounters with the physical world.

Sense data are mind-dependent representations of the physical world: they only exist in our minds and therefore are entirely subjective and relative to the particular circumstance of our perception.

  • sense data vary according to our location relative to the objects we perceive
  • they vary according to the functioning of our senses
  • they vary according to our mood and mental state
  • they vary according to their context amongst the other sense data that we get with them (staring at a tomato on a white plate in a small white room with no other distractions will produce different ‘sense data’ to an encounter with a speeding tomato as it whizzes past our head having been thrown at us by some tomato hurling hooligans)

So we can see that sense data are all about ‘perceptual variability’ or ‘perceptual relativity’. Therefore Russell and other indirect or representative realists have no problem explaining illusions, hallucinations, time lag arguments etc. in the way that that direct or naive realists do: for Russell these are just occasions when the sense data fail to match up with the physical world.

Causal Dependency

Russell does not attempt any ‘scientific’ account of the way in which the representations in our minds are connected to the objects in the world that they represent. That there is that some degree of causal dependency between the mental representation and the physical object is, he suggests the most likely and most reasonable conclusion to draw, but the nature or accuracy of this connection cannot be established and has the status of ‘working hypothesis’.

Representative or indirect realism is also known as ‘critical realism’ as well!

My ‘Dictionary of Philosophy’ defines it like this;

Critical realists claim that knowledge of the world can be gained because there is some sort of reliable correspondence between sensa, [sense data to us] or some sort intuitive data, on the one hand, and external objects on the other.

I think the word correspondence is really important and a very useful in talking writing about this stuff: what kind of correspondence is there between ‘sense data’ and the world they represent?

This understanding of the way we perceive the world tries to get around weaknesses of direct / naive realism by positing the idea of ‘sense data’ as intermediaries between the physical world and and our minds.

The ‘sense data’ allow us to form a representation of the ‘real’ physical world. The ‘sense’ data are ‘mind-dependent’: they do not only exist when we perceive the objects and they vary according to our perspective and circumstances. In this respect they allow for illusions, which are simply examples of the ‘sense data’ being unable to match up with reality accurately. Hallucinations are occasions when sense data occur without any corresponding stimulus in the physical world. And perceptual variation, is explained in the fact that ‘sense data’ are mind-dependent’ rather than object dependent and therefore vary according the individual’s different perspective or point of view on the world.
Although this theory seems to describe the way people experience the world more accurately than the clearly flawed naive realism, it has some very obvious problems of its own.
First of all it is not at all clear what the relationship is between the physical world and the ‘sense data’ that it seems to give rise to in us. If the sense data can be inaccurate as in the case of illusions, or entirely erroneous as in hallucinations, then how can we be sure that sense data actually represent anything at all?
Once the direct link between the supposed real physical world and our perception of it is called into doubt then the extent to which are representations of that world are accurate seems open to doubt, and a position of extreme scepticism seems possible.