⁂ Concepts · Logic · No. 71
Proposition

Two texts, one treaty, and a tribunal to decide what was said.

Proposition

The content expressed by a statement - what is true or false, as distinct from the words used to say it.

Theme
Logic, language and interpretation
Tradition
Analytic
Term fixed
1903

In plain terms

It is raining, il pleut and es regnet are three different sentences. They say the same thing, and that thing is what is true or false.

A proposition is the name for that shared content. The argument for needing one is straightforward: two people can believe the same thing in different languages, a translation can be accurate or inaccurate, and the same sentence can express different things on different occasions. Something has to be the item that is shared, translated and believed.

The argument against is that nobody can say what such an item is. It is not a sentence, not a thought in anyone's head, and not a fact - facts only correspond to the true ones. So it is an abstract object, invoked to do a job, with no independent evidence for its existence.

As a philosopher would put it

Propositions are standardly required to play several roles at once: the bearers of truth and falsity, the objects of belief and other attitudes, the meanings of declarative sentences, and the things shared by accurate translations. The difficulty is that the roles pull apart, and no account fills all of them comfortably.

The main accounts divide. Russellian propositions are structured entities containing objects and properties, which handles singular thought and generates problems for identity. Fregean propositions are composed of senses, which handles belief contexts and inherits the difficulties of sense. Possible-worlds accounts identify a proposition with the set of worlds where it is true, which is elegant and makes all necessary truths one proposition.

Deflationary and sententialist views deny the entities altogether and treat proposition-talk as shorthand for relations among sentences and speakers. Quine's objection is that propositions are individuated by synonymy, that no criterion of synonymy has survived scrutiny, and that entities without a criterion of identity should not be admitted.

Where you meet it

The Treaty of Waitangi was signed in 1840 in two texts, one English and one Māori, and the difference between them has been litigated for over a century and a half.

The English text has the chiefs cede sovereignty. The Māori text has them cede kāwanatanga, a transliteration approximating governorship, while the second article guarantees tino rangatiratanga, full chieftainship, over their lands and treasures - a word the English text renders as possession. Around five hundred chiefs signed the Māori text; thirty-nine signed the English.

The Waitangi Tribunal, established in 1975, was given the statutory task of determining the meaning and effect of the treaty and of deciding claims by reference to both texts. Its practice has been to apply the contra proferentem principle and give weight to the version the signatories actually understood. What the case makes visible is the assumption underneath ordinary translation: that there is one content two texts can express. Where that assumption fails, a legal system has to decide which document said what - and that is a philosophical question with a court attached.

What is actually disputed

Whether propositions exist.

Realists hold that the roles they play cannot be filled otherwise: something must be believed, translated and true, and sentences will not do because sentences are language-bound. Nominalists reply that this is an argument from convenience, that the entities have no criterion of identity, and that the roles can be discharged by relations among sentences, utterances and speakers without positing anything abstract.

A separate difficulty is unity. A proposition is not a mere list of its constituents - the proposition that Tom loves Mary differs from the one that Mary loves Tom, and both differ from a collection containing Tom, Mary and loving. What binds the constituents into something with a truth value is the problem of the unity of the proposition, which Russell wrestled with for years and did not solve, and which remains a live difficulty for structured accounts.

Defined against

  • Sign and symbol A proposition is what a sentence says; a sign is the physical thing that says it, and running them together is the confusion the notion exists to prevent

Philosophers

Works

Schools

Related concepts

Sense 1892 · Meaning 1892 · Truth c. 330 BC · Validity c. 330 BC · Interpretation 1819

The notion is ancient - the Stoic lekton is a recognisable ancestor - but the modern treatment of propositions as the objects of belief and the bearers of truth is early twentieth-century.