1. Wittgenstein’s Picture Theory

2. Biography

3. Ludwig Wittgenstein (1889-1951)
Jewish ancestry
Probably gay
Son of a steel baron: one of the richest people in the world
Engineering  math  philosophy of math  Frege  Russell

4. Ludwig Wittgenstein (1889-1951)
3 of his 4 brothers committed suicide
Participated in both world wars: first in the Austrian army, then in British hospitals
Constantly gave up philosophy

5. Ludwig Wittgenstein (1889-1951)
Wrote Tractatus while serving in the Austrian army and finished it while a prisoner of war in Italy.

6. Wittgenstein’s Rhino

7. Moore’s Paradox Compare: It’s raining but he doesn’t believe it.
It’s raining but I don’t believe it.

8. Moore’s Paradox
“It is alleged that after G.E. Moore gave the lecture in which his now- famous paradox was first formulated, Wittgenstein rushed around to Moore's quarters (for the two were at Cambridge together under the tutelage of Bertrand Russell) and insisted he repeat it in full.”

9. Wittgenstein’s Poker
Name a moral rule.

10. Recap from Last Time

11. Categories
Objects
States of affairs
Facts
The world
Form

12. Possibility & Logical Form
The chain metaphor (2.03)
The puzzle metaphor
Grammar metaphor

13. Divergence from Russell
Independence of facts & states of affairs (1.21, )
A priority of logical atomism ( )

14. Comprehension Check
2.032 In a manner of speaking, objects are colorless.

15. The Idea Theory

17. 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?

18. 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?

19. 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.

20. Idea Theory
Mind
Dagger
Idea of a Dagger

21. Hallucination
Mind
No Dagger
Idea of a Dagger

22. 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. Indirect realism allows us to maintain that there’s an appearance-gap between what we see (ideas) and the things that the ideas represent.

23. John Locke
Father of Classical Liberalism (civil liberties, economic freedom, limited government)
Along with Descartes, most important 17th Century Western philosopher.

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

25. Painting

26. The Nature of Ideas
According to Locke, ideas are “the pictures drawn in our minds” (Essay, II.x.5).

27. The Nature of Ideas
An idea of a horse, then, is very much like a picture, image, or painting of a horse. Compare Hume: “By ideas I mean the faint images of [perceptions] in thinking and reasoning” (Treatise, I.i.1).

28. Resembles
Sees
Mind
Dagger
Idea of a Dagger

29. 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.

30. Locke on General Terms
“It is not enough for the perfection of language, that sounds can be made signs of ideas, unless those signs can be so made use of as to comprehend several particular things…”

31. Locke on General Terms
“…for the multiplication of words would have perplexed their use, had every particular thing need of a distinct name to be signified by…”

32. Locke on General Terms
“To remedy this inconvenience, language had yet a further improvement in the use of general terms, whereby one word was made to mark a multitude of particular existences.”

33. Particular Terms
Locke

34. General Terms
Dog

35. Abstract Ideas
If we accept the idea theory, then, we have to accept that there are “abstract ideas”– not mental pictures of a particular person, but mental pictures that resemble equally a group of things. These abstract ideas are the meanings of general terms.

36. Berkeley vs. Abstract Ideas
The abstract idea of a man is supposed to apply equally to a tall man and a short man; a black man and a white man; a skinny man and a fat man; etc. Can there be such pictures?

37. Concepts
Concepts are representations of things or qualities: so I can have a concept of Obama, or a concept of red, or a concept of a horse, or a concept of a concept. Importantly, concepts are not truth-evaluable. My concept of red isn’t true, and it isn’t false either. It might be more or less accurate.

38. Propositions
We can say that when I think of a thing, or think about a thing, then I am entertaining a concept. However, when I think that such-and-such, I am entertaining a proposition.

39. Propositions
For example, I can think that Obama is the US president, or think that grass is red, or think that the concept of a horse is not a concept. Propositions are truth-evaluable: when I think that grass is red, my thought is false. (Not so when I just think of red.)

40. Dilemma
The idea theory seems to have trouble distinguishing concepts and propositions. According to the idea theory, thought is having ideas, and ideas are like mental pictures. Are mental pictures truth-evaluable? If they are, then concepts aren’t ideas. If they aren’t, then propositions aren’t ideas.

41. Berkeley and Resemblance
For Berkeley, only ideas could resemble ideas: a physical world of matter was wholly unlike an idea. This led Berkeley to embrace idealism, and view the “physical world” as actually made of ideas.

42. The Picture Theory

43. Wittgenstein’s Picture Theory
Logical “pictures”
Unity of the proposition/ fact
Abstracta
Concepts vs. propositions
2.161 There must be something identical in a picture and what it depicts to enable the one to be a picture of the other at all.

45. Wittgenstein’s Man on the Hill
“A picture which corresponds to a man walking up a hill forward corresponds equally, and in the same way, to a man sliding down the hill backward.”

46. Wittgenstein’s Man on the Hill
“Perhaps a Martian would describe the picture [as the man sliding down]. I do not need to explain why we do not describe it so.” -- Philosophical Investigations