Common Ground

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Common Ground The common ground in a conversation is the set of propositions that the interlocutors agree are true. Common Grounds differ depending on who the participants are, and the time of conversation. In our common ground: 53a. London is the capital of England b. We are in St Petersburg right now c. The current US President is Obama What else is in our common ground? Possibly not in our common ground: 54a. The Plantagenets ruled England before the Tudors did b. The name of the first French king is Clovis When you talk with your best friend, the Common Ground can contain propositions about your siblings, your teachers etc.

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Common Ground. The common ground in a conversation is the set of propositions that the interlocutors agree are true. Common Grounds differ depending on who the participants are, and the time of conversation. In our common ground: 53a. London is the capital of England - PowerPoint PPT Presentation

Transcript of Common Ground

Common GroundThe common ground in a conversation is the set of propositions that the interlocutors agree are true.

Common Grounds differ depending on who the participants are, and the time of conversation.

In our common ground:53a. London is the capital of England b. We are in St Petersburg right now c. The current US President is Obama

What else is in our common ground?

Possibly not in our common ground:54a. The Plantagenets ruled England before the Tudors did b. The name of the first French king is Clovis

When you talk with your best friend, the Common Ground can contain propositions about your siblings, your teachers etc.

New definition:

assertion …… common ground

An assertion is an act to attempt to add a proposition to the common ground.

Why “..to attempt…”?Because for it to be added to the common ground, the interlocutors have to accept the truth of the proposition. I can utter “Paris the capital of Lombardy” all I want, but it will not be added to the CG if you reject it.Of course, other things about my utterance WILL be added to the CG, like e.g. that I made a statement, that I don’t know geography or tried to fool you etc.

-’context set’=the set of worlds corresponding to the CG

-How would you define the notion of ‘presupposition’ wrt the notion ‘common ground’?

An assertion is an act to attempt to add a proposition to the common ground.

What if said proposition has certain presupposition(s)?

Can you still update the CG?

yes if

the CG entails the presupposition(s).(what does this mean?)

Then no problem, the CG gets updated.

Do you understand what this means:1a. A sentence is a function from the domain of Common Grounds to the domain of Common Grounds

b. A sentence is a function from the domain of Context Sets to Context Sets

(Context Set: the set of worlds that correspond to the propositions in the CG)

If you understand (1), you probably also understand (2):

2. To understand a proposition is to understand its Context Change Potential (CCP)

(For our purposes: Context=CG)

How is this different from what we saw earlier? What had we said earlier?

3. To understand a proposition is to know its truth-conditions.

2. To understand a proposition is to understand its Context Change Potential (CCP) (Heim)

(2) is the keystone of “dynamic semantics”.

Let’s go back to (1):

1. A sentence is a function from the domain of Common Grounds to the domain of Common Grounds.

What happens if CG1 does not entail the presuppositions of a proposition P? How does P fare as a function?What sort of function is P?A partial function.

A function is a mapping from one domain D1 into another domain D2.

A Partial function is a function that cannot take all elements of D1 as input and map them into D2.

(A total function is …)

A sentence is a partial function from CGs to CGs:It can only apply to CGs that entail the sentence’s presuppositions.

So:

To assert a proposition which has presuppositions is to place certain requirements on the CG.

Namely, that the CG entail the presuppositions.

• But what if the CG does not entail the presupposition(s)?

From the speaker’s perspective:

Let’s say P1 presupposes PS1.

CG does not entail PS1.

So uttering U1 in the CG should result in an unsuccessful assertion.

What would make you still want to utter U1 and attempt to update CG by P1?

The hope that the hearer will accommodate.

What is accommodation?

The act of adding the presupposition to the CG.(“without fuss”, “in pretense”)

We have now turned the CG into one that the asserted proposition can apply on as a function.

After accommodation, P can update the CG.

From the hearer’s perspective

When the speaker makes an assertion, and the proposition in question has presuppositions that are entailed by the CG, there is no issue.

What if the presuppositions are not entailed?Then accommodation comes into play.And you may want to do just that.

What determines whether you can/will accommodate?

What are some conditions under which accommodation is not possible?

When the CG entails the opposite of the proposition you are supposed to accommodate.You are supposed to accommodate φ but the CG entails ~φ.Examples?

How would you express your unwillingness to accommodate?

4. Napoleon Bonaparte, who was born in Detroit, was defeated at Waterloo

a. That’s false.b. You are wrong.c. Wait a minute! I didn’t know that…

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The Wait a minute! test(Shannon 1976)

• This is a test that distinguishes between presuppositions and assertions:

5.A: Mary’s brother is tall B: Wait a minute! I didn’t know Mary has a

brother! B’: #Wait a minute! I didn’t know he is tall!

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6. A: The mathematician who proved Goldbach’s Conjecture is a woman.

B: Hey, wait a minute! I had no idea that someone proved Goldbach’s Conjecture.

B’: #Hey, wait a minute! I had no idea that that was a woman.

What happens when a Proposition has presuppositions that you cannot accommodate?

Presupposition Failure.

Truth-value undefined.

And yet….

Sometimes, propositions that suffer from presupposition failures, feel false, not undefined.(Strawson 1950, von Fintel 2004)

7. # The King of France is bald8. FLast week, my friend went for a drive with the King of France.

9. The next-door neighbor offered me a larger sum(if there is no next-door neighbor, it’s F, rather than #)

This state of affairs endangers even the most rudimentary definition we started out with:

Sentence S1 is a presupposition of sentence S2 if S1 has to be true for S2 to have a Truth-value.

Why?

• So are we completely wrong on the nature of presuppositions?

Possible way(s) out:

7. # The King of France is bald8. FLast week, my friend went for a drive with the King of France.

Possible answer:In (7) there is an existential presupposition (EP), in (8) there isn’t. (many people believe this)More specifically, only definites that are topics have EPs. Therefore, only definites that are topics should induce # with EP failure.The definite is a topic in (7), but not in (8).

von Fintel 2004: wrong!

The usual presupposition tests still apply. That is the existence of the KoF is not asserted but presupposed (examples from von Fintel):

10. A: FThe King of France attended the APEC conference this week.B: Hey, wait a minute! I had no idea that France is still a monarchyB’:# Hey, wait a minute! I had no idea that he was at that conference

In (10) the King of France is still topical, it suffers form EP failure, yet the judgment is F, not #!

11. A: FThis year’s Fields Medal was awarded to the mathematician who proved Goldbach’s ConjectureB: Hey, wait a minute! I had no idea that someone proved the conjectureB’:#Hey, wait a minute! I had no idea that she got the medal

(von Fintel also shows that the EP projects like a presupposition but since we have not yet talked about presupposition projection, I will not go over that here)

So our tests are in conflict! We have sentences that have EPs that are not satisfied, yet the sentences DO have a Truth-value.Moreover, Topicality is not the defining factor for when we have F and when #.

More on the same conclusion: Topicality of definites with EP failure do not lead to #:

12. FI had breakfast with the King of France this morning. He and I had scrambled eggs.

13. A: Have you heard anything about the King of France recently? I think he may be getting old and decrepit B: FWell, Bill Clinton had breakfast with him last week and he looked just fine I hear.

Sentences in question have two things wrong with them:-EP failure-they contain an untruth independent of EP failure.

and here you can go read the not-small philosophical literature on this topic, starting with von Fintel section 5.

e.g., von Fintel, p. 280 discussing Lasersohn 1993: “The king of France is sitting in that chair is false for us since the following is true for us: Suppose I didn’t know that the king of France didn’t exist. Then, if I learnt that the king of France did exist, I would still know that he is not sitting in that chair (because that chair is empty)”

But the question has not been settled.

To remind you where we are:We were talking about accommodation and said that sometimes

-we can accommodate (without fuss): we just add the PS1 to the CG

-we cannot accommodate: when the CG entails ~PS1.

and then we saw that this sometimes yields #, sometimes F.

also:-we should in principle be able to accommodate, (i.e. the CG does not entail the polar opposite of the presupposition), but accommodation happens with difficulty or not at all.-I am sorry I am late. I had to take my giraffe to the vet-she is smart (when there is no woman around)-John is having dinner in NYC tonight too (when there is no other salient individual)

So these are a few words about accommodation but…--But we have now come very close to making the result of successful assertion (adding propositions to the CG) and successful accommodation (adding propositions to the CG) sound very much alike.

What are the differences?

• -if both happen wrt one utterance, they happen in a certain order.

examples?

• when you don’t want to add a proposition to the CG you react differently if it is a presupposition (i.e. when you would need to accommodate) from when it is an assertion

examples?

• Only matrix, not embedded, sentences are candidates for being added to the CG via assertion. On the other hand, embedded sentences can be added to the CG via accommodation.

examples?

This last difference is a manifestation of one of the most studied properties of presuppositions:

Presuppositions project!(and our last subunit in this class)

Presupposition Projection.

The study of how presuppositions project is the study of if/when/how the presuppositions of complex sentences are inherited from presuppositions of their parts.

[IP ………….[XP… presupposition trigger…]]

You have actually already seen two cases of presupposition projection, though we did not describe them as such at that point. What are they?

Presuppositions project out of questions:

14. Did Chris realize that gombats futter bravely?=>Gombats futter bravely

And out of embedding by negation:

15. Chris did not realize that gombats futter bravely

=>Gombats futter bravely

16. Is the King of France bald?17. The King of France is not bald.

18. It has been 5 years since his cat died=>His cat died

19. Has it been 5 years since his cat died=>His cat died

20. It has not been 5 years since his cat died.=>His cat died

Questions and Negation are what Karttunen 1973 calls “holes”: operators that permit presuppositions to “slip through”.If Op, is an operator, and φ a meaning that Op can operate on, then Op is a hole iff Op(φ) has all the presuppositions that φ has.(Holes provide a necessary, though not sufficient test for presuppositions)