Concept

Proposition

Overview

Propositions are the meanings of declarative sentences, objects of beliefs, and bearers of truth values. They explain how different sentences, such as the English "Snow is white" and the German "Schnee ist weiß", can have identical meaning by expressing the same proposition. Similarly, they ground the fact that different people can share a belief by being directed at the same content. True propositions describe the world as it is, while false ones fail to do so. Researchers distinguish types of propositions by their informational content and mode of assertion, such as the contrasts between affirmative and negative propositions, between universal and existential propositions, and between categorical and conditional propositions.

Many theories of the nature and roles of propositions have been proposed. Realists argue that propositions form part of reality, a view rejected by anti-realists. Non-reductive realists understand propositions as a unique kind of entity, whereas reductive realists analyze them in terms of other entities. One proposal sees them as sets of possible worlds, reflecting the idea that understanding a proposition involves grasping the circumstances under which it would be true. A different suggestion focuses on the individuals and concepts to which a proposition refers, defining propositions as structured entities composed of these constituents. Other accounts characterize propositions as specific kinds of properties, relations, or states of affairs. Philosophers also debate whether propositions are abstract objects outside space and time, psychological entities dependent on mental activity, or linguistic entities grounded in language. Paradoxes challenge the different theories of propositions, such as the liar paradox. The study of propositions has its roots in ancient philosophy, with influential contributions from Aristotle and the Stoics, and later from William of Ockham, Gottlob Frege, and Bertrand Russell.

Propositions are relevant to many fields. Logicians examine their logical form and inferential patterns as the premises and conclusions of arguments. Linguists investigate propositions as the meanings of declarative sentences and explore how natural language encodes this information, including the issues of ambiguity, vagueness, and context sensitivity. In psychology and philosophy of mind, researchers analyze how the mind deals with propositions, studying propositional attitudes such as belief, desire, and intention.

Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).

In the original texts

Passages from public-domain books where Proposition is discussed.

Chapter V. Of the Import of Propositions. § 1. Doctrine that a proposition is the expression of a relation between two ideas 96 2. Doctrine that it is the expression of a relation between the meanings of two names 99 3. Doctrine that it consists in referring something to, or excluding something from, a class 103 4. What it really is 107 5. It asserts (or denies) a sequence, a coexistence, a simple existence, a…
John Stuart Mill, Index of the Project Gutenberg Works of John Stuart Mill
names the idea; a chapter is titled for it; states what it is; opens on it
Read the chapter · Open in the reader
Not any series of words is a proposition, but only such series of words as have "meaning," or, in our phraseology, "objective reference." Given the meanings of separate words, and the rules of syntax, the meaning of a proposition is determinate. This is the reason why we can understand a sentence we never heard before.
Bertrand Russell, The Analysis of Mind
names the idea; states what it is; author linked in the graph; opens on it
Read the chapter · Open in the reader
We may go a step farther; it is the only analysis that is rigorously true of all propositions without exception. What he gives as the meaning of propositions, is part of the meaning of all propositions, and the whole meaning of some. This, however, only shows what an extremely minute fragment of meaning it is quite possible to include within the logical formula of a proposition. It does not show that no proposition…
John Stuart Mill, A System of Logic
names the idea; a chapter is titled for it; states what it is; opens on it
Read the chapter · Open in the reader
A form of words which must be either true or false I shall call a _proposition_. Thus a proposition is the same as what may be significantly asserted or denied. A proposition which expresses what we have called a fact, _i.e._ which, when asserted, asserts that a certain thing has a certain quality, or that certain things have a certain relation, will be called an atomic…
Bertrand Russell, Our Knowledge of the External World as a Field for Scientific Method in Philosophy
names the idea; states what it is; author linked in the graph
Read the chapter · Open in the reader
1. Truth and Falsehood properly belong to Propositions, not to Ideas. Though truth and falsehood belong, in propriety of speech, only to PROPOSITIONS: yet IDEAS are oftentimes termed true or false (as what words are there that are not used with great latitude, and with some deviation…
John Locke, An Essay Concerning Humane Understanding, Volume 1
names the idea; states what it is; author linked in the graph; opens on it
Read the chapter · Open in the reader

Proposition

Overview

In the original texts

Philosophers who discussed Proposition

Related ideas

Opposing perspectives

Place in the tradition