1. On your whiteboards…
What key information can you remember about Direct Realism? (Without your notes) What is the argument from illusion? Why is it a problem for DR?

2. DIRECT REALISM IN A NUTSHELL
Key features: 1. Direct realism claims that objects are composed of matter; they occupy space, and have properties such as size, shape, texture, smell, taste and colour. 2. These properties are perceived directly. In other words, when we look at, listen to and touch things, we see, hear and feel those things themselves with no intermediary (i.e. nothing getting in the way and distorting our perceptions). 3. DR also tends to suppose this means that we must perceive objects as they truly are (i.e. a door that looks red is really red) and we all see the same properties. 4. Importantly, objects also retain their properties whether or not there is anyone present to observe them; when you turn out the light to go to bed, the objects you can no longer see remain where they are and with the same shapes and colours as before. You may not be able to see it, but your door is still red.

3. THE ARGUMENT FROM ILLUSION
Direct realism states that the way we perceive things is the way they really are.
When we perceive illusions our senses are being deceived in some way (the stick looking bent in water despite not really being bent).
Therefore when we perceive illusions we are not perceiving the world the way it really is.
Conclusion: Direct realism is false.

4. Further Criticisms of Direct Realism
Lesson Objective: Consider further criticisms of Direct Realism including perceptual variation, hallucinations and time-lag.

5. Time to get Arty…

6. Why are the pictures different? You’re all perceiving the same Mike…
The Problem…
Why are the pictures different? You’re all perceiving the same Mike…

7. Enter Bertrand Russell…
“To make our difficulties plain, let us concentrate attention on the table. To the eye it is oblong, brown and shiny, to the touch it is smooth and cool and hard; when I tap it, it gives out a wooded sound. Anyone else who sees and feels and hears the table will agree with this description, so that it might seem as if no difficulty would arise; but as soon as we try to be more precise our troubles begin. Although I believe that the table is ‘really’ of the same colour all over, the parts that reflect the light look much brighter than the other parts, and some parts look white because of reflected light. I know that, if I move, the parts that reflect the light will be different, so that the apparent distribution of colours on the table will change.”
What issue is Russell highlighting here?

8. And angle isn’t the only issue…
Lighting conditions:
Hot and Cold:
Distance:

9. It’s a matter of privilege…
The problem here is that we don’t know which one of us has the privileged status of actually observing ‘reality’ as it really is:
Is it the person closest to the object?
Is it the person with the best senses?
Is it the person who can perceive the most of the object?
Or are objects changing their attributes constantly according to who is perceiving them and where from?

10. THE ARGUMENT FROM PERCEPTUAL VARIATION
Similar to illusions, the issue of perceptual variation seems to leave direct realism in a tight spot. Where the believer must accept something strange in order to continue to support the theory either:
Objects change their attributes constantly in accordance with the location and senses of the perceiver.
The direct realist is wrong and our perception of an object is not always identical to that object.

11. THE ARGUMENT FROM PERCEPTUAL VARIATION
Can you formalise the argument from perceptual variation?

12. Issue 3: Hallucinations
Is this a dagger I see in front of me, with its handle pointing toward my hand? (to the dagger) Come, let me hold you. (he grabs at the air in front of him without touching anything) I don’t have you but I can still see you. Fateful apparition, isn’t it possible to touch you as well as see you? Or are you nothing more than a dagger created by the mind, a hallucination from my fevered brain? I can still see you, and you look as real as this other dagger that I’m pulling out now. (he draws a dagger) You’re leading me toward the place I was going already, and I was planning to use a weapon just like you. My eyesight must either be the one sense that’s not working, or else it’s the only one that’s working right.
What is going on here?

13. Issue 3: Hallucinations
Whilst this speech from Macbeth is about a visual hallucination, it’s worth noting that there are plenty of examples of auditory hallucinations as well. Why does the occurrence of these hallucinations present a problem for DR?

14. Issue 3: Hallucinations
In the case of hallucinations we seem to perceive things that are actually not there. What we are acquainted with in non-veridical (untruthful; inaccurate) experience can be phenomenologically identical to that of veridical (truthful; accurate) experience, meaning we experience the two in the same manner as they have the same ‘feel’.

15. Issue 3: Hallucinations
The problem for the direct realist is that if the world is exactly as it appears then hallucinations must, contrary to popular belief, actually be a part of the world. The direct realist cannot seem to distinguish between perceiving something which is there and seeming to perceive something which in reality is not there, as they are not prepared to admit that reality might be different from the appearance of reality.

16. Issue 3: Hallucinations
Can you formalise this argument?

17. How long does it take light from the sun to reach the earth?
Issue 4: Time-Lag
How long does it take light from the sun to reach the earth?
Does this mean if we looked at the sun we would be observing it as it really is?

18. Issue 4: Time-Lag
There was a supernova explosion in the crab nebula in the constellation of Taurus that is observable from Earth. The only issue? It occurred 6000 years ago (as that’s how long light takes to travel to us)! In that time the entire nebula could have vanished and we wouldn’t know any different!

19. Issue 4: Time-Lag + Sound
It’s not just a matter of light either… Sound travels significantly slower than light, meaning if we are listening to something from a great distance (say a stage at a festival) we are actually hearing things milliseconds after they actually happen. The further away the greater the gap!

20. Russell on Time-Lag
But the sense-datum which we call hearing the thunder does not take place until the disturbance of the air has travelled as far as to where we are. Similarly, it takes about eight minutes for the sun's light to reach us; thus, when we see the sun we are seeing the sun of eight minutes ago. So far as our sense-data afford evidence as to the physical sun they afford evidence as to the physical sun of eight minutes ago; if the physical sun had ceased to exist within the last eight minutes, that would make no difference to the sense data which we call ‘seeing the sun’.

21. Can you formalise this argument?
Issue 4: Time-Lag
Can you formalise this argument?

22. How accurate?
How accurate do you think our senses are when it comes to seeing the way the world really is? 1-10 with a reason for your choice.
Not at all accurate
Very accurate 1 10

23. Task
Summarise the four criticisms of Direct Realism using pictures (remember changing the media form will help you remember information).
How effective do you think these criticisms are? Are they enough to categorically show DR as false? Summarise your thoughts as a paragraph on a whiteboard.
Can you think of any responses to these issues?

24. Lesson Summary