intro to modality Flashcards
Modality: intro
> Operates at SENTENCE LEVEL
> Speakers can make simple assertions:
- Leo has gone to tokyo
- Leo hasn't gone to tokyo
(Both carry unspoken guarantee of "to the best of my knowledge"
MODALITY allows speakers to MODULATE GUARANTEE
> signal stronger or weaker commitment to factuality
>LINGUISTIC STRATEGIES:
adverbs, adjectives, modal verbs, propositional attitude verbs…
Linguistic strategies to alter Modality
MODAL VERBS: shall, should, can, could, may, might, would, must, ought to
NOUNS: possibility, necessity, likelihood
ADJECTIVES: possible, probable, necessary, likely, certain
ADVERBS: possibly, probably, necessarily, maybe, perhaps
MAIN VERBS: require, hope, believe, think, doubt etc.
MODALITY DEGREES OF STRENGTH
adjectives, propositional attitude verbsm modals
ADJECTIVES - strong to weak commitment: It’s certain that p It’s probable that p It’s likely that p It’s possible that p
PROPOSITIONAL ATTITUDE VERBS: I know that p I believe that p I think that p I don’t know that p I doubt that p I know that not p
MODALS: She must have left by now She might have left by now She could have left by now She needn’t have left by now She couldn’t have left by now
LOGICAL NECESSITY
- Necessarily, The sum of the angles of a triangle equals 1800.
- Necessarily if John is a bachelor he is unmarried.
Compare with: - John is a bachelor
> (1) and (2) illustrate LOGICAL NECESSITY: not contingent on actual circumstances
(3) = CONTINGENT, dependent on facts making it true
Logical necessity means THE PROPOSITION CANNOT BE FALSE
If p = The sum of the angles of a triangle equals 1800.
>(1) is represented as: [] p (“Necessarily p”)
[] = logical symbol for necessity (regardless of type of modality)
LOGICAL POSSIBILITY
> It is possible for a person to win Lotto five times in a row. (Optimist, anonymous)
Even if no one has ever won lotto 5 times in a row, it remains a logical possibility
Sentence thus illustrate logical possibility: POSSIBILITY that is NOT CONTINGENT on facts or circumstances
<> p: it is possible that p (<> = symbol for possibility)
Epistemic Modality: EPISTEMIC NECESSITY
Must = GIVEN WHAT WE KNOW, p is the only possible conclusion we can draw
> Epistemic Refers to necessity or possibility of a proposition being true given what is already known
(A note of absence) Dear Teecher, Johnny couldn’t go to skool yesteday coz I was sick.
Mum.
(Teacher) The author of the letter must be the child.
Facts: (1) spelling mistakes & handwriting are typical of Johnny; (2) use of pronouns and name signed reveal
perspective of child; (3) paper used was cut out of a school homework diary.
> “The book must be in Professor Smith’s office.”
» Book listed in catalogue, but not in library; topic is on tomato/pig hybridization; only Prof. Smith works on
the topic. (Portner)
Epistemic Modality: EPISTEMIC POSSIBILTY
Epistemic possibility: ‘possible given what we know’
Traditionally, ‘may have + past participle’ was considered to express epistemic possibility:
“The spaceship may have been sucked into a black hole.”
»“There’s no trace of it.”
On the other hand, ‘might have + past participle’ traditionally considered to be ambiguous:
“The spaceship might have been sucked into a black hole..”
a. “There’s no trace of it.”
b. “Luckily, Captain Picard made it not so…”
(a): interpretation where S expresses epistemic possibility
(b): interpretation where S expresses logical possibility
DEONTIC MODALITY: deontic necessity
“You must wear a scarf to enter this building.”
“Rich people should give money to the poor.”
Sentences illustrate deontic necessity
Deontic modality is concerned with the necessity or possibility of facts performed by morally responsible
agents
> concerned with compliance with some code of behaviour
(code = pragmatic matter)
DEONTIC MODALITY: deontic possibility
Deontic possibility expresses what is permitted, allowed
> Timmy’s allowed to stay up late tonight.
What about:
“You can sing.”
a. said by a mother to a child after homework;
b. said by a judge to one of the competitors on The Voice.
(a) : deontic reading;
(b) : epistemic reading
Hearer needs to figure out precisely which worlds are relevant to a modal sentence
»This is a pragmatic matter!!
Other types of modalities Circumstancial abilitative bouletic teleological
CIRCUMSTANTIAL modality: concerns material conditions that allow a situation to be the case > olive trees can grow here (bc of soil)
ABILITATIVE modality:
(in view of his physical abilities) Max can lift 200 pounds.
BOULETIC modality: desires
> (in view of his desire to retire at 50) Josh should work hard now.
TELEOLOGICAL modality: goals > (in view of his goal to win the race) Josh must train every day
Modality & Possible Worlds
MODAL LOGIC
Operators understood as quantifiers over possible worlds []p = ‘it is necessary that p’ MUST > "Aw(p is true in w) <>p = ‘it is possible that p’ MAY > Ew(p is true in w)
We can specify type of world:
- w0 = actual world
- w = logical (any world)
- we = epistemic
- wpo = deontic (‘perfect obedience worlds’)
Modality summary
Modal FORCE represented with QUANTIFIERS over possible worlds
> Universal vs Existential
Modal “FLAVOR” has quantification restricted to a particular SUBSET OF WORLDS (epistemic, deontic)
Modal logic concerned with patterns of inferences
>Not with linguistic idiosyncracies
> Some insights crucial to understanding modality in NL
>Some linguistic questions need further exploration
Modals: Lexical ambiguity?
Do modals come with two distinct meanings in the lexicon?
Fred may watch TV.
>“For all we know, it is possible that Fred is a TV watcher” (may1, epistemic)
> “Fred is allowed to watch TV” (may2, deontic)
ROLE OF CONTEXT Deontic reading: also ‘subflavors’ > In view of his father’s/mother’s orders, the rules of the dorm/prison etc.. >How much more ambiguity? > ‘In view of ’ phrase disambiguates
