Truth is conformity to reality or fact. It contrasts with falsity or misrepresentation that fails to align with the world. Truth is typically treated as a property of entities such as sentences, propositions, or beliefs that describe things as they are. It is closely related to truthfulness, a virtue associated with honesty, and to truthlikeness, a characteristic of theories that approximate the truth.
Various theories of the nature of truth have been proposed, but its precise definition remains contested. The correspondence theory holds that a statement is true if it corresponds to facts. According to the coherence theory, truth consists in logical consistency and mutual support among beliefs. Pragmatists understand truth in terms of practical consequences and epistemic practices, claiming that truth is what works or what would withstand the test of unlimited inquiry. The semantic theory analyzes the truth conditions of sentences in an object language from the perspective of a metalanguage. Deflationary theories argue that truth has no significant intrinsic nature, holding that the linguistic role of truth-related expressions exhausts the concept of truth. Pluralists assert that the definition of truth varies with the domain of analysis, while relativists maintain that the same statement can be true in one perspective and false in another. Theories of truth are challenged by logical paradoxes, such as the liar paradox. There are also discussions about the existence of additional truth values besides true and false and about the possibility of truth value gaps—statements that have no truth value.
Philosophers distinguish types of truth by domain, content, and epistemic access, including a priori, necessary, moral, aesthetic, religious, and scientific truths. Truth plays a central role in the sciences as a goal of inquiry. The empirical sciences seek truth through observation and experimentation, whereas the formal sciences rely on deductive reasoning from fundamental principles. Many religious traditions regard truth as a virtue and ground it in a divine source. Truth also acts as a guiding norm in the fields of ethics, law, and journalism.
Discussions of truth arose in antiquity in Hindu, Jain, Buddhist, and Greek thought. In the medieval period, Christian and Islamic philosophers explored the relation between truth and God. Discussions in the modern and contemporary periods have addressed diverse topics, such as the nature of truth and its relation to thought, language, and reality.
