1. KNOWLEDGE OF THE EXTERNAL WORLD THEORIES OF PERCEPTION

2. Why an issue? Sensory perception a key source of our beliefs about the world. Empiricism – senses the basis of knowledge.

3. Key questions What is the relationship between me (the subject) and the world? What is the relationship between appearance and reality? When I perceive something, what is it that I am aware of? How are misperceptions and illusions to be explained? What happens when an object is not being perceived? What can we know of it?

4. The common sense approach to the questions… One’s awareness or perception is directly of the object. The object exists independently of us. The object is the cause of my perceptual experience. When unperceived the object retains (at least some of) its properties…. Worries

5. The challenge of illusions

11. PARIS IN THE THE SPRING

12. The challenge to direct realism The Time-Lag Argument. There is a time lag between my perception of an object and the object actually having the properties I perceive it to possess.

13. Well-known objection to direct realism but one that is easily answered. It trades on a confusion between two senses of immediate. Immediate #1:without delay Immediate #2:direct, without anything coming between.

14. A bigger worry… Misperception and Illusion a round coin can appear elliptical from certain angles, a straight stick bent when in water, parallel lines convergent as they move into the distance, a non-existent limb can feel painful to an amputee The basic problem is how to explain why an apparently direct relationship with the world can give rise to such errors. Also – think about how we can explain the phenomenal sameness of really seeing a small green man and having an hallucination of a small green man.

15. Physics and perceptual experience Physics tells us how the world really is. Yet we do not experience the world as it is described in our best physical theory, even though according to direct realism it is with the world as such that I have direct contact. Furthermore, at least some of the properties an object has seem to depend upon the perspective of the observer

16. The appeal to representative realism…