---
title: "Presuppositions as Beliefs — paper by Horton and Hirst (1988)"
description: "They propose instead that each presupposition is a belief held by a specific agent. 15 references, cited by 2 papers here."
authors: ["Diane Horton", "Graeme Hirst"]
year: 1988
venue: "Coling Budapest 1988 Volume 1: International Conference on Computational Linguistics"
source: "https://aclanthology.org/C88-1052/"
licence: "CC BY-NC-SA 3.0 (ACL Anthology, before 2016)"
licence_url: "https://creativecommons.org/licenses/by-nc-sa/3.0/"
summary_licence: "Elamur Cosmic License"
canonical: "https://research.elamur.ai/free/en/papers/horton-1988-presuppositions-as-beliefs/"
---
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# Presuppositions as Beliefs

**Authors:** Diane Horton and [Graeme Hirst](https://md.research.elamur.ai/free/en/authors/graeme-hirst/) · **Year:** 1988 · **Venue:** [Coling Budapest 1988 Volume 1: International Conference on Computational Linguistics](https://md.research.elamur.ai/free/en/venues/coling/) ([COLING 1988](https://md.research.elamur.ai/free/en/venues/coling/1988/)) · **Licence:** [CC BY-NC-SA 3.0 (ACL Anthology, before 2016)](https://creativecommons.org/licenses/by-nc-sa/3.0/)

**Links:** [Publisher's page](https://aclanthology.org/C88-1052/) · [PDF](https://aclanthology.org/C88-1052.pdf) · [OpenAlex](https://openalex.org/W2061668628)

**Citations:** 15 citations (OpenAlex, 2026-10-14) · [2](https://md.research.elamur.ai/free/en/papers/horton-1988-presuppositions-as-beliefs/cited-by/) in our library, of the 149,439 papers whose bibliographies we read

## Summary
The paper challenges a common hidden premise in theories of presupposition: that what a sentence presupposes is simply true and already believed by everyone in the conversation. Horton and Hirst name these premises the Truth Assumption and the Shared Belief Assumption. They propose instead that each presupposition is a belief held by a specific agent. That agent is not always the speaker, so the beliefs of every participant must be taken into account.

They use a formal logic of nested belief, built on belief structures, a variant of the knowledge structures of Fagin, Halpern and Vardi. They also give a new definition that separates *potential* presuppositions, which come from the sentence alone, from *actual* ones, which are checked against what the listener believes. The definition uses the behaviour of a candidate inference under negation to tell presupposition apart from entailment and implicature.

The account explains how presuppositions can carry new information and how they are later cancelled. The authors see the integration of agents' beliefs as their main contribution beyond Gazdar's consistency-based theory.

## Key points
- The paper rejects two assumptions: the Truth Assumption (a presupposition is true) and the Shared Belief Assumption (all agents believed it beforehand). It also argues that Levinson's mutual-knowledge definition is too strict, because presuppositions often introduce new information.
- Table 1 lists the triggers covered: factive verbs, it-clefts, change-of-state verbs, non-restrictive relative clauses, implicative verbs, definite descriptions and verbs of judging.
- The paper distinguishes two kinds of negation:
  - **Internal negation** has a clear focus. A presupposition survives it unless the negation targets that presupposition.
  - **External negation** is ambiguous. By default it is read as negating the main proposition, so the presupposition stands.
- "Defeat" covers two cases:
  - **Blocking:** the presupposition is never adopted because it clashes with established context.
  - **Retraction:** the presupposition is withdrawn when later evidence contradicts it, as in the Porsche example.
- The formal machinery consists of:
  - a belief logic with nested operators, such as John believing that Mary believes not-P;
  - Add Proposition and Retract Proposition operations, which are described only informally;
  - definitions of potential and actual presupposition, with an "anti-condition" for the rare affirmative sentences where defeat is felicitous.

## Interesting ideas
- Do not store a presupposition as a fact. Store it as a belief of a particular agent, for example "the speaker believes P," so that it can be disputed or retracted without corrupting the base facts.
- When negation is ambiguous, adopt the reading that negates the main proposition by default, but keep the presupposition marked as retractable if later sentences contradict it.
- Use a negation test to classify inferences. A candidate counts as a presupposition only if it still holds when the sentence is externally negated, unless the listener already believes the opposite.
- Separate what the sentence alone can trigger (potential) from what holds once checked against the listener's beliefs in context (actual).
- Attribute beliefs to the listener and to third parties, not only the speaker, using nested beliefs such as "L believes Sp believes not-P."

## For Mova

How these ideas could serve Mova, our small open language model — its files, stages and tests:

- **I1** (world): Presupposed propositions in the world of the text could be tagged with a believer and a source utterance, so that answers can tell what is asserted from what a character merely assumes.
- **I2** (frames): crate prag could attach a "defeasible" flag and a retraction hook to presuppositions under negation, and log the evidence whenever one is withdrawn so the step stays explainable.
- **I3** (learn): This gives a cheap negative control for evaluation: negate test sentences automatically and check that presupposition outputs persist while entailment outputs disappear.
- **I4** (frames): Trigger rules keyed on UD patterns, such as factive complements, clefts and change-of-state verbs, could produce potential presuppositions, and a later consistency check against the world would promote them to actual ones.
- **I5** (answer): QA on fables and tales could answer "what did the fox think the crow believed" by querying nested belief records instead of a flat fact store.

*Our summary of the paper, in our own words — not its text. The work belongs to its authors; read it at the links above.*

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- [University of Toronto](https://md.research.elamur.ai/free/en/universities/university-of-toronto/) — University, Toronto, Canada · 96 works · 142,007 citations

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## Cite

Cite as: Diane Horton and Graeme Hirst. 1988. Presuppositions as Beliefs. Coling Budapest 1988 Volume 1: International Conference on Computational Linguistics.

The paper itself, not this page. BibTeX from the library's record of the work.

```bibtex
@inproceedings{horton1988presuppositions,
  title = {{Presuppositions as Beliefs}},
  author = {Diane Horton and Graeme Hirst},
  booktitle = {Coling Budapest 1988 Volume 1: International Conference on Computational Linguistics},
  year = {1988},
  doi = {10.3115/991635.991687},
  url = {https://doi.org/10.3115/991635.991687}
}
```

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## References

15 references, 0 of them with a card of ours. ↗ leads to the work, «find» searches for one we have no id for yet.

1. Atlas, J.D.; and Levinson, S.C. 1981. It-Clefts, Informativeness, and Logical Form: Radical Pragm~tics (Revised Standard Version). In Cole, P. Ed., t2adieaI Pragmatics. Academic Press: 1-61. [find](https://scholar.google.com/scholar?q=Atlas%2C+J%2ED%2E%3B+and+Levinson%2C+S%2EC%2E+1981%2E+It%2DClefts%2C+Informativeness%2C+and+Logical+Form%3A+Radical+Pragm%7Etics+%28Revised+Standard+Version%29%2E+In+Cole%2C+P%2E+Ed%2E%2C+t2adieaI+Pragmatics%2E+Academic+Press%3A+1%2D61%2E)
2. Fagin, Ronald; Halpern, Joseph Y.; and Vardi, Moshe Y. 1984. A Model~Theoretic Analysis of Knowledge: Preliminary Report. Proceedings of the 25th IEEE Symposium on Foundations of Computer Science. West Palm Beach, Florida: 268-278. [find](https://scholar.google.com/scholar?q=Fagin%2C+Ronald%3B+Halpern%2C+Joseph+Y%2E%3B+and+Vardi%2C+Moshe+Y%2E+1984%2E+A+Model%7ETheoretic+Analysis+of+Knowledge%3A+Preliminary+Report%2E+Proceedings+of+the+25th+IEEE+Symposium+on+Foundations+of+Computer+Science%2E+Wes)
3. Gazdar, G. 1979a. Pragmatics: Implieature, Presupposition and Logical Form. Academic Press. [find](https://scholar.google.com/scholar?q=Gazdar%2C+G%2E+1979a%2E+Pragmatics%3A+Implieature%2C+Presupposition+and+Logical+Form%2E+Academic+Press%2E)
4. Gazdar, G. 1979b. A Solution to the Projection Problem. In Oh and Dinneen 1979: 57-89. [↗](https://doi.org/10.1163/9789004368880_003)
5. Grice, H. Paul. 1975. Logic and Conversation. In Cole, Peter J.; and Morgan, Jerry L., Eds. Syntax and Semantics, Volume 3: Speech Acts. Academic Press: 41-58. [↗](https://doi.org/10.1163/9789004368811_003)
6. Horton, Diane Lynn. 1987. ,Incorporating Agents' Beliefs in a Model of Presupposition. M.Se. thesis, published as Technical Report CSRI-201, Computer Systems Research Institute, University of Toronto, Toronto, Canada. [find](https://scholar.google.com/scholar?q=Horton%2C+Diane+Lynn%2E+1987%2E+%2CIncorporating+Agents%27+Beliefs+in+a+Model+of+Presupposition%2E+M%2ESe%2E+thesis%2C+published+as+Technical+Report+CSRI%2D201%2C+Computer+Systems+Research+Institute%2C+University+of+Toronto%2C)
7. Karttunen, Lauri. 1973. Presuppositions of compound sentences. Linguistic Inquiry 4:169-193. [find](https://scholar.google.com/scholar?q=Karttunen%2C+Lauri%2E+1973%2E+Presuppositions+of+compound+sentences%2E+Linguistic+Inquiry+4%3A169%2D193%2E)
8. Karttunen, Lauri. 1974. Presupposition and linguistic context. Theoretical Linguistics 1:181-194. [↗](https://doi.org/10.1515/thli.1974.1.1-3.181)
9. Karttunen, Lauri; and Peters, Stanley. 1979. Conversational Inlplicature. In Oh and Dinneen 1979: 1-56. [find](https://scholar.google.com/scholar?q=Karttunen%2C+Lauri%3B+and+Peters%2C+Stanley%2E+1979%2E+Conversational+Inlplicature%2E+In+Oh+and+Dinneen+1979%3A+1%2D56%2E)
10. Levinson, S.C. 1983. Pragmatics. Cambridge University Press. [find](https://scholar.google.com/scholar?q=Levinson%2C+S%2EC%2E+1983%2E+Pragmatics%2E+Cambridge+University+Press%2E)
11. Oh, C.-K.; and Dinneen, D.A., Eds. 1979. Syntax and Semantics, Volume 11: Presupposition. Academic Press. [find](https://scholar.google.com/scholar?q=Oh%2C+C%2E%2DK%2E%3B+and+Dinneen%2C+D%2EA%2E%2C+Eds%2E+1979%2E+Syntax+and+Semantics%2C+Volume+11%3A+Presupposition%2E+Academic+Press%2E)
12. Quirk, Randolph; and Greenbanm, Sidney. 1973. A University Grammar of English. Longman Group Limited. [find](https://scholar.google.com/scholar?q=Quirk%2C+Randolph%3B+and+Greenbanm%2C+Sidney%2E+1973%2E+A+University+Grammar+of+English%2E+Longman+Group+Limited%2E)
13. Weischedel, Ralph Mark. 1975. Computation of a Unique Subclass of Inferences: Presupposition and Entailment. Unpublished doctoral dissertation, University of Pennsylvania. [find](https://scholar.google.com/scholar?q=Weischedel%2C+Ralph+Mark%2E+1975%2E+Computation+of+a+Unique+Subclass+of+Inferences%3A+Presupposition+and+Entailment%2E+Unpublished+doctoral+dissertation%2C+University+of+Pennsylvania%2E)
14. Weischedel, Ralph Mark. 1979. A New Semantic Computation While Parsing: Presupposition and Entailme~L In Oh and Dinneen 1979: 155-183. [find](https://scholar.google.com/scholar?q=Weischedel%2C+Ralph+Mark%2E+1979%2E+A+New+Semantic+Computation+While+Parsing%3A+Presupposition+and+Entailme%7EL+In+Oh+and+Dinneen+1979%3A+155%2D183%2E)
15. Wilson, Dierdre; and Sperber, Dan. 1979. Ordered Entaihnents: An Alternative to Presuppositional Theories. In Oh and Dinneen 1979: 299-323. [find](https://scholar.google.com/scholar?q=Wilson%2C+Dierdre%3B+and+Sperber%2C+Dan%2E+1979%2E+Ordered+Entaihnents%3A+An+Alternative+to+Presuppositional+Theories%2E+In+Oh+and+Dinneen+1979%3A+299%2D323%2E)

*Updated 1 November 2026*