modal logic

Formal logic able to express concepts such as necessity, possibility, provability, obligation, knowledge etc.

Conceptmathematical theory academic disciplineQ210841

Instance of: mathematical theory
, academic discipline
Subclass of: logical system
, intensional logic
Part of: logic
, mathematical logic

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

Modal logic is a kind of logic used to represent statements about necessity and possibility. In philosophy and related fields it is used as a tool for understanding concepts such as knowledge, obligation, and causation. For instance, in epistemic modal logic, the formula can be used to represent the statement that is known. In deontic modal logic, that same formula can represent that is a moral obligation. Modal logic considers the inferences that modal statements give rise to. For instance, most epistemic modal logics treat the formula as a tautology, representing the principle that only true statements can count as knowledge. However, this formula is not a tautology in deontic modal logic, since what ought to be true can be false.

Overview

All data

48 statements · 17% with external sources · numbers in brackets are citations

Influenced by: propositional calculus
predicate logic

On other databases

35 identifiers linking modal logic across the web's reference databases

Data quality

statements

17%

externally sourced

Source last edited July 10, 2026. AIDB refreshes this page daily.

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AIDB. (2026). modal logic (Q210841). Retrieved from https://aidb.si/e/modal-logic-Q210841