Presentation on theme: "Presuppositions (and Focus) Sabine Iatridou. What does it mean to understand (the meaning of) a sentence? Do you understand this sentence? 1.The instructor."— Presentation transcript:
What does it mean to understand (the meaning of) a sentence? Do you understand this sentence? 1.The instructor of this class is wearing glasses Is it true? Yes. Do you understand this sentence? 2. The instructor of this class is wearing pink a hat Is it true? No. 2
What about this sentence: 3. It is raining in Beijing right now Is this sentence true or false? You don’t know. Yet, you know what it would take for it to be true. So to understand a sentence, is to know its “truth-conditions”. The truth-conditions of a sentence S1 are the conditions under which S1 is true. 3
Assertions Let’s call an ‘assertion’ the act by which one commits oneself to the truth of the sentence uttered. (we will shortly give a better definition) Often, when we utter a sentence, we make an assertion. But not always. Can you think of examples where we utter a sentence but do not make an assertion?
Relations among sentences: Entailment A sentence S1 entails a sentence S2 if whenever S1 is true, S2 is true. (though we will come back to this definition) 4.S1: I drank horseradish vodka and ate serniki 5. S2: I drank horseradish vodka => 5
Entailment is not about whether a sentence is actually true. The actual fact of the matter is irrelevant. What is relevant is whether the truth of one sentence makes another sentence necessarily true. For example, I suspect that (6) is false: 6. All MIT students have tried horseradish vodka But even if (6) is false, it still entails (7) and (8): 7. Half of MIT students have tried horseradish vodka 8. All the students in my syntax class at MIT have tried some type of vodka 6
Entailment does not have to be symmetric. (9) entails (10) but (10) does not entail (9): 9. The cheetah killed the gazelle 10. The gazelle died Why? 7
But of course, it can be symmetric, as two sentences can entail each other. Can you think of two sentences that entail each other? 11. The police arrested the demonstrator 12. The demonstrator was arrested by the police When two sentences entail each other, we say that they are equivalent: S1 and S2 are equivalent if S1 entails S2 and S2 entails S1. 8
Further inferences 13. Chris believes that gombats futter bravely 14. Chris realized that gombats futter bravely What does (14) convey that (13) does not? In (14) there is an inference that I / the speaker believes that gombats futter bravely. (this inference is usually described as ‘gombats futter bravely’ being true) Is this inference cancellable? 15a. Chris believes that gombats futter bravely, but I don’t believe it b. Chris believes that gombats futter bravely, but he is wrong c. Chris believes that gombats futter bravely, but I don’t know if they do
16a. #Chris realized that gombats futter bravely, but I don’t believe it b. #Chris realized that gombats futter bravely, but he is wrong c. #Chris realized that gombats futter bravely, but I do not know if they do
17. Chris believes that the earth is flat 18. Chris realized that the earth is flat How about the following predicates? Can you use them without believing that the earth is flat? hear, discover, be aware that, say, regret Factive predicates: realize, discover, be aware that, regret
19. What is your opinion about Mimi and Lena? 20. I like Lena Inference: 21. I don’t like Mimi that much (or at all) Is it cancellable? 22.… but I adore Mimi (as a follow-up on 20)
Some inferences are cancellable, some are not. The inferences that are cancellable are called “conversational implicatures”. Conversational implicatures are not part of the encoded meaning, unlike entailments (and unlike presuppositions, as we will see shortly). They are inferences that a hearer can draw based on the cooperativity and rationality of the speaker, basically reasoning about the speaker’s intentions.
Implicatures are all around us. 23. Do you know what the time is? 24. A: Do you sell limes? B: I sell lemons A: What European country will you visit next year? B: One with a Mediterranean coast
Or when we hear numbers: 3 children implicates exactly 3 children When you hear 25a. Max has three children this implicates b. Max has exactly three children But you can cancel this: 26.A: If someone has three children, they are entitled to a tax break B: Max has three children. In fact, he has four.
Sentence S2 is an implicature of sentence S1, if S2 is inferred upon hearing S1, without being entailed. i.e. S1 can be true without S2 being true i.e. an implicature is cancellable S1: Max has three children S2: Max has exactly three children
Back to the non-cancellable inferences 27. Chris realized that gombats futter bravely 28a. #Chris realized that gombats futter bravely, but I don’t believe it b. #Chris realized that gombats futter bravely, but he is wrong What is the relationship between (27) and the inference in (29) 29. Gombats futter bravely
Is it entailment? 27. Chris realized that gombats futter bravely entails?? 29. Gombats futter bravely Could the answer to this question be ‘yes’? Could the answer to this question be ‘no’?
Let’s take a case where for sure we are dealing with entailment: 30. I drank horseradish vodka and ate serniki => 31. I drank horseradish vodka
Chris drank vodka and ate serniki Did Chris drink vodka and eat serniki? ≠> Chris drank vodka Chris did not drink vodka and eat serniki ≠> Chris drank vodka Chris realized that gombats futter bravely Did Chris realize that gombats futter bravely? => Gombats futter bravely Chris did not realize that gombats futter bravely => Gombats futter bravely So if the left column shows the bahavior of entailments under questions and negation (the inference disappears), the inferences in the right column should not be called entailments as well, as their behavior is different (the inferences survive questions and negation).
The inferences in the left column do not survive questions or negation. Let’s reserve the term ‘entailments’ for those. But the inferences in the gombat sentences do. Therefore we should not call these inferences ‘entailments’. We should call these inferences something else, and explore their properties.
Presuppositions Presuppositions are inferences that survive questions and negation. Factive verbs presuppose the truth of their complement. Factive verbs are ‘presupposition triggers’ But there is more:
32a. Chris realized that gombats futter bravely presupposes b. Gombats futter bravely What happens if a presupposition does not hold (is false)? 33. Chris realized that London is the capital of France So what is the status of (33)? Is it a true sentence? Is it a false sentence?
If it is false, negation should make it true: Imagine (34, 35) uttered in a world in which Hedde believes that Paris is the capital of France: 34. Hedde believes that London is the capital of France F 35. Hedde does not believe that London is the capital of FranceT But negating (36) does not yield a true sentence: 36. Chris realized that London is the capital of France 37. Chris did not realize that London is the capital of France (36, 37) suffer from presupposition failure: it is false (in our world) that London is the capital of France.
What if a sentence suffers from presupposition failure? Two views: -false (Russell) -undefined (Frege) What would you say?
Which brings us to one more way to describe presuppositions: Sentence S1 is a presupposition of sentence S2 if S1 has to be true for S2 to have a Truth-value.
Factive verbs are presupposition triggers. There are many presupposition triggers. Some are verbs, like the factive verbs. Some determiners (classic example of a presupposition trigger):
38. The present king of France is bald Presupposes: There is a king of France (= existential presupposition) Presupposes: There is only one king of France (=uniqueness presupposition) What does (38) assert? Asserts: The present King of France is bald We will say more later about how to distinguish asserted content from presuppositional content.
Some are adverbs: 39. Bill failed the test again 40. Bill failed the test too What does (39) assert? Bill failed the test What does (39) presuppose? He had failed the test before What does (40) assert? Bill failed the test What does (40) presuppose? Somebody in addition to Bill failed the test
Some presupposition triggers are constructions: 41. It is Miranda who broke the computer Presupposes: 42. Somebody broke the computer Asserts: 43. Miranda broke the computer
So, presuppositions are inferences which survive questions survive negation have to be true for the sentence that contains them to have a truth-value But why should these properties pattern together? And there is one more property that is considered basic about presuppositions (and gives them their name):
When we utter a sentence that has presuppositions, the presuppositions are not part of the new information we want to convey. Instead, we take the presuppositional content as already known. This helps us determine what the assertion and what the presupposition of the utterance is For example, when I tell you 38. The present king of France is bald The new thing that I am telling you is not that there is a king of France. I am presupposing that you know that. The new information that I want to give you is that this person is bald.
39. Bill failed the test again 40. Bill failed the test too Similarly, when I tell you (39), I am assuming you already know that Bill failed the test once before. When I tell you (40), I am assuming you already know that somebody other than Bill failed the test.
So, when I tell you: 44. My brother gave me this watch I am presupposing that I have a brother. What I am asserting is that he gave me this watch. But does this seem correct?
Can’t I tell you 44. My brother gave me this watch if you don’t know that I have a brother? For sure I can! But my having a brother is still expressed as a presupposition in (44). How can we express something as a presupposition even if its truth is not taken for granted by the interlocutors?
The hearer accommodates the presupposition. “If at time t something is said that requires presupposition P to be acceptable, and if P is not presupposed just before t, then –ceteris paribus and within certain limits– presupposition P comes into existence at t” David Lewis 1979: “Scorekeeping in a language game” Journal of Philosophical Logic 8(1):339- 359.
Presuppositions survive questions survive negation have to be true for the sentence that contains them to have a truth-value are taken for granted by the interlocutors or accommodated by the hearer(s) Why should these properties cluster together?
Two more basic notions for today In a previous slide we talked about sentences having truth-conditions. Let’s improve on that a bit. Let’s call a ‘sentence’ any constituent of the syntactic category IP. We defined ‘assertion’ as the act by which one commits oneself to the truth of the sentence uttered.
A sentence that makes an assertion, expresses a ‘proposition’. (some think of a proposition as the “thought” expressed by a sentence) It is propositions that are true or false. (not sentences) Let’s keep the two notions separate: Some, not all, sentences express a proposition. For example, questions and commands are sentences but they do not express propositions Two different sentences can express the same proposition: 45. The cheetah killed the gazelle 46. The gazelle was killed by the cheetah
Two different sentences in different languages can express the same proposition: 47. The cheetah killed the gazelle 48. Гепард убил газель
A sentence can express a different proposition depending on the context it is uttered in. 49. I am wearing a hat right now Sentence (49) expresses a different proposition depending on -who is uttering it. -when it is being uttered.
So propositions and sentences are not the same thing. Even so, we often speak sloppily and talk about sentences having truth-values etc.
So sentences are linguistic objects. A common way of thinking of propositions is as a set of possible worlds, specifically, those worlds in which the proposition holds/is true. Why a plurality of worlds? Let us say that (50) is true. 50. The instructor talking right now is wearing glasses Imagine a world in which (50) is true and (51) is also true: 51. It is raining right now in Bejing
w 1 : The instructor is wearing glasses It is raining in Bejing But we can also have w 2 : w 2 : The instructor is wearing glasses It is not raining in Bejing Do you know which world we are in?
And of course, there are infinitely many ways to describe a world. Just add one more sentence: 52. The number of people in the building right now is odd Before we had two possible worlds: w 1 : The instructor is wearing glasses It is raining in Bejing w 2 : The instructor is wearing glasses It is not raining in Bejing
Now we have 4 possible worlds: w 3 : The instructor is wearing glasses It is raining in Bejing The number of people in the building right now is odd w 4 : The instructor is wearing glasses It is raining in Bejing The number of people in the building right now is not odd w 5 : The instructor is wearing glasses It is not raining in Bejing The number of people in the building right now is odd w 6 : The instructor is wearing glasses It is not raining in Bejing The number of people in the building right now is not odd In all these worlds, it is true that the instructor is wearing glasses. This is why a proposition corresponds to the set of worlds in which it is true.