Idealism

1. Idealism

3. Macbeth, Act I, scene i Is this a dagger which I see before me, The handle toward my hand? Come, let me clutch thee. I have thee not, and yet I see thee still. Art thou not, fatal vision, sensible To feeling as to sight? or art thou but A dagger of the mind, a false creation, Proceeding from the heat-oppressed brain?

4. Hallucinations Normally we talk as though we see physical things, out there in the world. “I see a dagger”– a dagger is obviously not mental. But what do I see when I hallucinate a dagger?

5. Ideas A popular view among 17th and 18th Century Western philosophers was that what you really saw was ideas– mental things. On this view, ideas were something like little colored pictures in the mind.

6. Idea Theory Dagger Mind Idea of a Dagger

7. Hallucination Mind No Dagger Idea of a Dagger

8. Indirect Realism Views of this general form are called “indirect realism.” What you directly see are mental entities (for example, ideas). You only indirectly see the real things that the ideas represent.

9. Resemblance Theory According to the resemblance theory of representation, ideas represent things by resembling them– sort of like how painting works.

10. Painting

11. Resembles Sees Dagger Mind Idea of a Dagger

12. Resemblance This means that even though what you see are ideas, the ideas are close copies of the real things, the way a realistic painting is a close copy of a scene.

13. Corpuscularianism In the 17th Century, corpuscularianim was the dominant scientific worldview. It held that all physical things are made of tiny little things called “corpuscles.” The theory was very similar to Greek atomism, with the exception that atoms couldn’t be divided and corpuscles (in theory) could.

14. Corpuscularianism Part of the theory held that corpuscles only had shape, size, solidity, and motion. They did not have color, taste, texture, smell, or heat, though they could cause us to experience these things by exciting our sense organs.

15. Partly Resembles Sees Dog Mind Idea of a Dog

16. Terminology Locke called properties like shape, size, and motion– properties that both ideas and real things could have– primary qualities. Other properties that only ideas had were called secondary qualities.

17. Subjective idealism

18. George Berkeley (1685-1753)

19. George Berkeley George Berkeley was an Irish philosopher and Bishop in the Church of Ireland. He advocated a view which we now call “subjective idealism.”

20. Fun Fact The town of Berkeley, California was named after Berkeley, inspired partly by the final stanza of Verses on the Prospect of Planting Arts and Learning in America, “Westward the course of empire takes its way; The first four Acts already past, A fifth shall close the Drama with the day; Time's noblest offspring is the last.”

21. Subjective Idealism Berkeley denied corpuscularianism and materialism, the idea that things were made out of corpuscles or matter. Instead, Berkeley thought that things like tables, and mountains, and human bodies, were made out of ideas.

22. EsseestPercipi Berkeley’s slogan was “esseestpercipi,” to be is to be perceived. Appearance = reality. An idea only exists when a mind “perceives” the idea. Since tables and mountains are made out of ideas, they don’t exist until and unless someone perceives them.

23. Berkeley’s Principles Berkeley’s most important philosophical work is the Treatise Concerning the Principles of Human Knowledge, Part I. (Part II was lost on a trip to Italy, and Berkeley never re-wrote it.)

24. Motivations Berkeley had two main goals for his philosophical project. • First, he wanted to eliminate the skepticism inherent in indirect realism (how can we know that the world is how our ideas say it is?). • Second, he wanted to end philosophy and turn everyone’s attention to God.

25. Argument that “Material Objects” are Really Made out of Ideas §4 (a) You can see a mountain/ hear a bird/ smell a rose/ taste a soup/ feel the rain (b) What you see are sights, what you hear are sounds, you smell smells, taste tastes, feel textures. (c) Sights, sounds, smells, etc. are ideas. (d) So mountains/ birds/ roses/ soups/ rain are all ideas.

26. Arguments against materialism/ realism/ corpuscularianism

27. For Berkeley and for the indirect realists, what you perceive directly are ideas. Berkeley says that having an idea and perceiving an idea are the same thing: ‘To have an idea is all one as to perceive’ §7.

28. Seeing = Imagining = Hallucinating Mind Idea of a Dagger

29. With this assumption, Berkeley argues that you cannot imagine things that exist but are not perceived. Since matter is supposed to be existent even when it is not perceived, Berkeley is arguing that we cannot imagine matter.

31. Imagining a Lonely Tree Mind Idea of a Dagger

32. Imagining a Lonely Tree Mind Idea of a Dagger

33. If we can’t even imagine matter, then it would seem weird to say that we believed in it.

34. Second Argument We cannot have ideas of things with no color, taste, smell, texture, etc. Corpuscles, according to the theory, have no color, taste, smell, texture, etc. Therefore we cannot have an idea of a corpuscle.

35. All qualities are secondary qualities

36. Secondary Qualities Secondary qualities are the properties of ideas that are not also properties of material things. According to Locke they were things like color, smell, taste, texture, and warmth or coldness. Berkeley argues that actually all qualities are secondary: only ideas resemble ideas.

37. COLD HOT NORMAL

38. FEELS COLD FEELS HOT COLD HOT NORMAL

39. FEELS HOT FEELS COLD COLD HOT NORMAL

40. Berkeley’s strategy is to use the same kind of “bucket” reasoning to show that all the properties that corpuscles are supposed to have– size, shape, and motion– are really secondary qualities.

41. That’s a SMALL elephant.

42. That’s a BIG elephant.

46. Conclusion of the Argument Berkeley concludes that size, shape, and motion are secondary qualities: properties of ideas, not of material objects. So anything that has size or is shaped or moves is an idea. That’s pretty much everything.

47. The abductive argument for materialism/ realism

48. The Abductive Argument Here’s an argument against Berkeley: “Look, the existence of a mind-independent reality is the best explanation for our experiences. If tables and chairs etc. were ‘just ideas’ that wouldn’t explain why everyone looking in the same place sees the same thing.”

49. Reply: This requires that the physical objects cause our ideas. But no-one has any clue how physical-to-mental causation is supposed to work. So this can’t be the best explanation.

50. Furthermore, according to corpuscularianism, our ideas are caused (mysteriously) by the shape size and motion of the corpuscles acting on our sensory organs. But: (a) Shape, size, and motion are ideas (b) Ideas are passive: they cannot cause a change in other ideas.__________________ (c) Therefore, shape, size, and motion can’t cause a change in our ideas.