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Linglib.Studies.AnandHacquard2013

Anand & Hacquard 2013: epistemics and attitudes #

[AH13] (Semantics & Pragmatics 6:8) survey the distribution of epistemic modals in the complements of attitude verbs across French, Italian, and Spanish: epistemics are fully acceptable under attitudes of acceptance (doxastics, argumentatives, semifactives), degraded under desideratives and directives, and emotive doxastics (hope, fear) and dubitatives (doubt) show a mixed pattern — possibility but not necessity.

The account combines two proposals. Epistemics quantify over an information state parameter obtained by anaphora to the embedding attitude ([Yal07], [Hac06]); attitudes split by representationality ([Bol68]): representational attitudes convey a mental picture and so provide an information state S = DOX(x,w), non-representational ones combine with their complement by comparative preference semantics ([Vil08]) and provide none, and hybrids have both components — the representational component licenses possibility epistemics while the uncertainty condition blocks necessity. Representationality, AttitudeClass, and LicensesEpistemic render the classification, and theory_matches_data checks the prediction against the paper's pooled acceptability survey.

The final section maps the hybrid structure onto Bayesian theory-of-mind inference ([BJEST17]; [HKWH+23]): the doxastic, preference, and uncertainty components are the belief marginal, the desire marginal, and non-extreme credence of a prospective emotion.

The representationality classification #

Classification of attitude semantics by representationality: an attitude is representational iff its semantics provides a non-trivial information state that embedded epistemics can be anaphoric to (§3).

  • representational : Representationality

    Provides the information state S = DOX(x,w): doxastics, argumentatives, semifactives.

  • nonRepresentational : Representationality

    No information state: desideratives and directives, whose comparative semantics ([Vil08]) supplies S = ∅.

  • hybrid : Representationality

    Both components: a representational component providing DOX and a preference component ordering alternatives — emotive doxastics and dubitatives.

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      Epistemic modal force.

      • possibility : EpistemicForce

        might, may (∃ over the information state).

      • necessity : EpistemicForce

        must, have to (∀ over the information state).

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          The central prediction: representational attitudes license both forces, non-representational ones neither (the trivial modal base yields tautology or contradiction), and hybrids license possibility only — the uncertainty condition contradicts universal quantification over DOX.

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            Epistemic licensing requires an information state.

            The seven attitude classes of the survey.

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                Epistemic licensing for an attitude class, via its representationality.

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                  Empirical Data: Acceptability Ratings (Table 4) #

                  Cross-Romance Survey Data #

                  Seven-point acceptability ratings (1 = unacceptable, 7 = completely acceptable) for epistemic modals under attitude verbs, pooled across French (n=31), Italian (n=11), and Spanish (n=21).

                  Table 4: Pooled Descriptive Statistics (mean (sd) / median) #

                  des/directemo doxdubitativesemifactiveacceptMean
                  might3.5/35.1/66.1/76.1/76.4/75.4 (1.8)/6
                  must1.9/12.7/23.1/25.6/66.0/73.9 (1.7)/4
                  probable2.4/34.2/54.8/65.6/76.2/75.0 (1.9)/5

                  The critical contrasts:

                  The survey collapses some classes (doxastics ≈ argumentatives, desideratives ≈ directives), but the theory predicts the same licensing for collapsed classes — verified cell by cell in theory_matches_data.

                  Acceptability judgment: acceptable (median ≥ 5) or degraded.

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                      Observed acceptability from the survey data, indexed by the full AttitudeClass from Representationality.lean. Argumentatives pattern with doxastics; directives pattern with desideratives.

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                        Predicted licensing: the prediction follows from the representationality classification, not per-cell stipulation.

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                          Theory Matches Data #

                          The representationality theory correctly predicts all 14 cells (7 attitude classes × 2 epistemic forces).

                          Information State Semantics (Yalcin's S parameter) #

                          Epistemic Modals as Information-State Quantifiers #

                          Following [Yal07] and [Vel96], epistemic modals quantify over an information state parameter S:

                          ⟦might φ⟧^{c,w,S,g} = 1 iff ∃w' ∈ S: ⟦φ⟧^{c,w',S,g} = 1
                          ⟦must φ⟧^{c,w,S,g} = 1 iff ∀w' ∈ S: ⟦φ⟧^{c,w',S,g} = 1
                          

                          Attitude verbs update S with their quantificational domain:

                          ⟦att φ⟧^{c,w,S,g} = λx. ∀w' ∈ S': ⟦φ⟧^{c,w',S',g} = 1
                          where S' = quantificational domain provided by att
                          

                          For representational attitudes: S' = DOX(x,w) (non-trivial) For non-representational attitudes: S' = ∅ (trivial → tautology/contradiction)

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                          abbrev AnandHacquard2013.InfoState (W : Type u_2) :
                          Type u_2

                          Information state: a set of worlds (represented as a list).

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                            def AnandHacquard2013.mightS {W : Type u_1} (S : InfoState W) (φ : WProp) :

                            Epistemic possibility over information state S: ⟦might φ⟧_S = ∃w' ∈ S: φ(w')

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                              instance AnandHacquard2013.instDecidableMightSOfDecidablePred {W : Type u_1} {S : InfoState W} {φ : WProp} [DecidablePred φ] :
                              Decidable (mightS S φ)
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                              def AnandHacquard2013.mustS {W : Type u_1} (S : InfoState W) (φ : WProp) :

                              Epistemic necessity over information state S: ⟦must φ⟧_S = ∀w' ∈ S: φ(w')

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                                instance AnandHacquard2013.instDecidableMustSOfDecidablePred {W : Type u_1} {S : InfoState W} {φ : WProp} [DecidablePred φ] :
                                Decidable (mustS S φ)
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                                Non-triviality presupposition ([Geu05]): epistemics presuppose their modal base is non-trivial.

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                                  instance AnandHacquard2013.instDecidableNonTrivialOfDecidableEq {W : Type u_1} [DecidableEq W] {S : InfoState W} :
                                  Decidable (nonTrivial S)
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                                  theorem AnandHacquard2013.might_defined_iff_nontrivial {W : Type u_1} (S : InfoState W) (φ : WProp) [DecidablePred φ] (_h : nonTrivial S) :
                                  mightS S φ ¬mightS S φ

                                  Epistemic possibility is defined (non-trivial) whenever S ≠ ∅.

                                  theorem AnandHacquard2013.might_empty {W : Type u_1} (φ : WProp) :
                                  ¬mightS [] φ

                                  With empty S, might is trivially false — yielding infelicity.

                                  theorem AnandHacquard2013.must_empty {W : Type u_1} (φ : WProp) :
                                  mustS [] φ

                                  With empty S, must is trivially true — yielding infelicity.

                                  Attitude Embedding: S-Update #

                                  def AnandHacquard2013.representationalS {W : Type u_1} {E : Type u_2} (R : EWWProp) [(a : E) → (w w' : W) → Decidable (R a w w')] (agent : E) (w : W) (worlds : List W) :

                                  Representational attitude embedding: S' = DOX(x,w). The doxastic alternatives form the information state that embedded epistemics quantify over.

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                                    Non-representational attitude embedding: S' = ∅. Comparative semantics provides no information state.

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                                      theorem AnandHacquard2013.representational_nontrivial {W : Type u_1} {E : Type u_2} (R : EWWProp) [(a : E) → (w w' : W) → Decidable (R a w w')] (agent : E) (w : W) (worlds : List W) (h : w'worlds, R agent w w') :
                                      nonTrivial (representationalS R agent w worlds)

                                      Representational attitudes yield non-trivial information states (when there is at least one accessible world).

                                      Non-representational attitudes yield trivial information states.

                                      Deriving the Distribution #

                                      theorem AnandHacquard2013.believe_must {W : Type u_1} {E : Type u_2} (R : EWWProp) [(a : E) → (w w' : W) → Decidable (R a w w')] (agent : E) (w : W) (worlds : List W) (p : WProp) [DecidablePred p] :
                                      mustS (representationalS R agent w worlds) p Doxastic.BoxAt R agent w worlds p

                                      Under a representational attitude, embedded must p holds iff all doxastic alternatives satisfy p — a non-trivial claim.

                                      Under a non-representational attitude, must p is trivially true.

                                      Under a non-representational attitude, might p is trivially false.

                                      The emotive doxastic lexical entry (56) #

                                      ⟦a hopes_C that p⟧: defined iff both p-verifiers and p-falsifiers exist among the doxastic alternatives (the uncertainty condition); where defined, true iff some doxastic alternative verifies p (the doxastic assertion) and the p-verifiers are preferred to the p-falsifiers above the contextual threshold (the preference assertion). φ-verifiers in S are the subsets of S certain about φ — for unmodalized p, pow(S ∩ p) — so verifier/falsifier non-emptiness is mightS S p ∧ mightS S ¬p. The doxastic component is what lets hope answer a question ([Sch08b]'s dialogue, attributed to Truckenbrodt: "Kommt Peter heute?" — "Ich hoffe/*will, dass er heute kommt") and distinguishes hope from pure-preferential want.

                                      def AnandHacquard2013.hopeAt {W : Type u_1} {E : Type u_2} (R : EWWProp) [(a : E) → (w w' : W) → Decidable (R a w w')] (μ : EFinset W) (θ : List (Finset W)) (agent : E) (p : Finset W) (w : W) (worlds : List W) (C : List (Finset W)) :

                                      The (56) entry over the study's information-state semantics: presupposition = uncertainty, assertion = doxastic possibility plus preference. The doxastic conjunct is entailed by the first presupposition conjunct; the paper states it separately as the component embedded epistemics are anaphoric to.

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                                        theorem AnandHacquard2013.must_contradicts_uncertainty {W : Type u_1} {E : Type u_2} (R : EWWProp) [(a : E) → (w w' : W) → Decidable (R a w w')] (μ : EFinset W) (θ : List (Finset W)) (agent : E) (p : Finset W) (w : W) (worlds : List W) (C : List (Finset W)) (h_must : mustS (representationalS R agent w worlds) fun (x : W) => x p) :
                                        ¬(hopeAt R μ θ agent p w worlds C).presup w

                                        Embedded must p contradicts the uncertainty presupposition ((48) against (47c)): if p holds throughout the doxastic state, there are no falsifiers — epistemic necessity is blocked under hope and fear.

                                        theorem AnandHacquard2013.might_concord {W : Type u_1} {E : Type u_2} (R : EWWProp) [(a : E) → (w w' : W) → Decidable (R a w w')] (agent : E) (p : WProp) (w : W) (worlds : List W) (h : mightS (representationalS R agent w worlds) p) :
                                        mightS (representationalS R agent w worlds) fun (x : W) => mightS (representationalS R agent w worlds) p

                                        Embedded might p contributes the same doxastic content as bare p ((58), modal concord): a modalized complement is settled by the shared information state, so its verifiers are the p-verifiers — epistemic possibility is licensed.

                                        Emotive Doxastic Finite Model #

                                        Concrete Demonstration #

                                        We instantiate the abstract theory with a finite model demonstrating the must/might asymmetry under emotive doxastics.

                                        World model: 3 worlds {w₁, w₂, w₃}

                                        John's beliefs (DOX): {w₁, w₂} — uncertain whether it's raining. John's preference: raining worlds preferred to non-raining.

                                        Predictions:

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                                            John's doxastic accessibility: worlds w₁ and w₂ are doxastically accessible (he's uncertain), w₃ is not.

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                                              John's DOX is non-trivial (he has beliefs).

                                              "might be raining" is true in John's DOX — there's a raining world.

                                              "must be raining" is false in John's DOX — there's a non-raining world.

                                              Uncertainty: both raining and non-raining worlds in DOX.

                                              BToM Connection: Prospective Emotions = Emotive Doxastics #

                                              The BToM–Emotive Doxastic Bridge #

                                              [HKWH+23]'s emotion model computes retrospective appraisals from BToM marginals. We show that [AH13]'s emotive doxastic semantics gives the formal content of prospective emotions computed from the same marginals.

                                              The mapping:

                                              A&H componentBToM computation
                                              Doxastic assertionbeliefMarginal: Pr(b | a) > 0 for b ⊨ φ
                                              Uncertainty condition0 < Σ_b Pr(b|a)·⟦φ⟧_b < 1
                                              Preference assertiondesireMarginal: Σ_d Pr(d|a)·U(φ,d) > Σ_d Pr(d|a)·U(¬φ,d)

                                              This unification means:

                                              theorem AnandHacquard2013.hope_from_uncertainty_and_preference (cred u_true u_false : ) (h_pos : 0 < cred) (h_lt_one : cred < 1) (h_pref : u_false < u_true) :
                                              { beliefCredence := cred, utilityIfTrue := u_true, utilityIfFalse := u_false }.isHope = true

                                              Hope holds from uncertainty + positive preference over resolutions.

                                              theorem AnandHacquard2013.fear_from_uncertainty_and_dispreference (cred u_true u_false : ) (h_pos : 0 < cred) (h_lt_one : cred < 1) (h_pref : u_true < u_false) :
                                              { beliefCredence := cred, utilityIfTrue := u_true, utilityIfFalse := u_false }.isFear = true

                                              Fear holds from uncertainty + negative preference over resolutions.

                                              theorem AnandHacquard2013.necessity_contradicts_uncertainty (cred : ) (h_high : cred 1) (h_lt : cred < 1) :
                                              False

                                              The uncertainty condition in the emotive doxastic semantics is the same as requiring non-extreme credence in the BToM framework: Pr(φ) > 0 ∧ Pr(φ) < 1 ↔ ∃w' ∈ DOX: φ(w') ∧ ∃w' ∈ DOX: ¬φ(w').

                                              This is the formal content of why necessity epistemics are blocked: Pr(φ) ≥ θ_must (≈ 1) contradicts Pr(φ) < 1.