1. Rule-Following, Meaning and Coordination Giacomo Sillari gsillari@sas.upenn.edu Lorentz Center Workshop on Formal Theories of Communication 24/2/2010

2. Giacomo Sillari gsillari@sas.upenn.edu

5. Make the following experiment: say “It’s cold here” and mean “It’s warm here”. Can you do it? Ludwig Wittgenstein, Philosophical Investigations § 510

6. Giacomo Sillari gsillari@sas.upenn.edu I can’t say “it’s cold here” and mean “it’s warm here”—at least not without a little help from my friends David Lewis, Convention: A Philosophical Study, p.177

7. Giacomo Sillari gsillari@sas.upenn.edu I can’t say “it’s cold here” and mean “it’s warm here”—at least not without a little help from my friends David Lewis, Convention: A Philosophical Study, p.177

8. Giacomo Sillari gsillari@sas.upenn.edu Background Kripke’s skeptical paradox... –indeterminacy of interpretation

9. Giacomo Sillari gsillari@sas.upenn.edu Background Kripke’s skeptical paradox... –indeterminacy of interpretation …and its skeptical solution –correctness conditions held in the community

10. Giacomo Sillari gsillari@sas.upenn.edu Background Kripke’s skeptical paradox... –indeterminacy of interpretation …and its skeptical solution –correctness conditions held in the community Normativity of rule-following –Past use –Dispositions –Mental States

11. Giacomo Sillari gsillari@sas.upenn.edu Background What do correctness conditions consist of?

12. Giacomo Sillari gsillari@sas.upenn.edu Background What do correctness conditions consist of? Equilibria of recurrent coordination games

13. Giacomo Sillari gsillari@sas.upenn.edu Rules and Conventions

14. Giacomo Sillari gsillari@sas.upenn.edu Rules and Conventions § 198 “A person goes by a sign-post only in so far as there exists a regular use of sign-posts, a custom.”

15. Giacomo Sillari gsillari@sas.upenn.edu Rules and Conventions § 198 “A person goes by a sign-post only in so far as there exists a regular use of sign-posts, a custom.” “[w]e need more than a generalized awareness of the importance of social processes: we need a specific understanding of what is meant by the word ‘institution’” (Bloor 1997)

16. Giacomo Sillari gsillari@sas.upenn.edu Rules and Conventions § 198 “A person goes by a sign-post only in so far as there exists a regular use of sign-posts, a custom.” “[w]e need more than a generalized awareness of the importance of social processes: we need a specific understanding of what is meant by the word ‘institution’” (Bloor 1997)

17. Giacomo Sillari gsillari@sas.upenn.edu Rules and Conventions § 198 “A person goes by a sign-post only in so far as there exists a regular use of sign-posts, a custom.” Lewis-conventions Regularity in the solution of recurrent coordination games

18. Giacomo Sillari gsillari@sas.upenn.edu Rules and Conventions § 198 “A person goes by a sign-post only in so far as there exists a regular use of sign-posts, a custom.” Lewis-conventions Regularity in the solution of recurrent coordination games Conventions as “a kind of social norms”?

19. Giacomo Sillari gsillari@sas.upenn.edu Rules and Conventions § 198 “A person goes by a sign-post only in so far as there exists a regular use of sign-posts, a custom.” Lewis-conventions Regularity in the solution of recurrent coordination games Conventions as “a kind of social norms”? “How, then, do I explain accepting a norm? I explain it by placing it in a speculative psychology. Accepting a norm, I hypothesize, is a state of mind that is linked to a special kind of linguistically infused motivation or tendency. The tendency, roughly, is to do what the norm says. The psychic mechanisms that underlie this state have as a chief biological function coordination through discussion---with coordination taken in the broad, game-theoretic sense expounded by Thomas Schelling (Gibbard 1994)

20. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following

21. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following (§198) “[W]hat has the expression of a rule […] got to do with my actions?” (§201) This was our paradox: no course of action could be determined by a rule, because any course of action can be made out to accord with the rule [and] it can also be made out to conflict with it.”

22. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following (§198) [A]ny interpretation still hangs in the air along with what it interprets, and cannot give it any support. (§202) And to think one is obeying a rule is not to obey a rule.”

23. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following (§202) And hence also ‘obeying a rule’ is a practice. (§201) [T]here is a way of grasping a rule which is not an interpretation, but which is exhibited in what we call “obeying the rule” and “going against it” in actual cases.

24. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following Expression of a rule

25. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following Expression of a ruleSituation (sign-post)

26. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following Expression of a rule Interpretation of a rule Situation (sign-post)

27. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following Expression of a rule Interpretation of a rule Situation (sign-post) Possible actions (strategies): “Going in the direction of its finger or (e.g.) in the opposite one” (§85)

28. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following Expression of a rule Interpretation of a rule Following a rule Situation (sign-post) Possible actions (strategies): “Going in the direction of its finger or (e.g.) in the opposite one” (§85)

29. Giacomo Sillari gsillari@sas.upenn.edu Wittgenstein on Rule-following Expression of a rule Interpretation of a rule Following a rule Situation (sign-post) Possible actions (strategies): “Going in the direction of its finger or (e.g.) in the opposite one” (§85) Practice (actual play): Coordination on equilibrium or miscoordination

30. Giacomo Sillari gsillari@sas.upenn.edu Rule-following and Coordination

31. Giacomo Sillari gsillari@sas.upenn.edu Rule-following and Coordination

32. Giacomo Sillari gsillari@sas.upenn.edu Rule-following and Coordination

33. Giacomo Sillari gsillari@sas.upenn.edu What do correctness conditions consist of? Equilibria of (recurrent) coordination games Meredith Williams (1989): “The normativity of rules is grounded in community agreement over time.”

34. Giacomo Sillari gsillari@sas.upenn.edu What do correctness conditions consist of? Equilibria of (recurrent) coordination games Meredith Williams (1989): “the community is not required in order to police the actions and judgments of all members, but in order to sustain the articulated structure within which understanding and judging can occur and against which error and mistake can be discerned.”

35. Giacomo Sillari gsillari@sas.upenn.edu What do correctness conditions consist of? Equilibria of (recurrent) coordination games Meredith Williams (1989): “the community is not required in order to police the actions and judgments of all members, but in order to sustain the articulated structure within which understanding and judging can occur and against which error and mistake can be discerned.”

36. Builder-Assistant Game S Lack of slab“Slab!”Bring a slab Lack of pillar“Pillar!”Bring a pillar Giacomo Sillari gsillari@sas.upenn.edu

37. Builder-Assistant Game StateSignalAction Lack of slab“Slab!”Bring a slab Lack of pillar“Pillar!”Bring a pillar Giacomo Sillari gsillari@sas.upenn.edu

38. Builder-Assistant Game StateSignalAction Lack of slab“Slab!”Bring a slab Giacomo Sillari gsillari@sas.upenn.edu

39. Builder-Assistant Game StateSignalAction Lack of slab“Slab!”Bring a slab Lack of pillar“Pillar!”Bring a pillar Giacomo Sillari gsillari@sas.upenn.edu

40. Builder-Assistant Game State Lack of slab“Slab!”Bring a slab Lack of pillar“Pillar!”Bring a pillar Giacomo Sillari gsillari@sas.upenn.edu

41. Builder-Assistant Game StateSignalAction Lack of slab“Slab!”Bring a slab Lack of pillar“Pillar!”Bring a pillar Giacomo Sillari gsillari@sas.upenn.edu

42. Builder-Assistant Game StateSignalAction Lack of slab“Slab!”Bring a slab Lack of pillar“Pillar!”Bring a pillar Giacomo Sillari gsillari@sas.upenn.edu

43. Builder-Assistant Game StateSignalAction Lack of slab“Slab!”Bring a slab Lack of pillar“Pillar!”Bring a pillar Giacomo Sillari gsillari@sas.upenn.edu

44. Signaling Games StateSignalAction s1“  1”a1 s2“  2”a2 Giacomo Sillari gsillari@sas.upenn.edu

45. Builder-Assistant Game StateSignalAction Cold“it’s cold here!”Turn up heat Warm“it’s warm here!”Open window Giacomo Sillari gsillari@sas.upenn.edu

46. Builder-Assistant Game StateSignalAction Cold“it’s cold here!”Turn up heat Warm“it’s warm here!”Open window Giacomo Sillari gsillari@sas.upenn.edu