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1 Theories of truth

The study of truth is part of philosophical logic and epistemology. Sentences, propositions, statements, ideas, beliefs, and judgments can be true, and are called truth bearers by philosophers.

There are several broad theories about truthThis article is primarily concerned with truth as it is used in the evaluation of assertions. For example, The world is a sphere" is true''. When used in this way, it is properly contrasted with false''. Truth is a concept of primary importance to philoso that philosopherA philosopher is a person devoted to studying and producing results in philosophy. The word, "philosopher," literally means "lover of wisdom. Popular Western philosophers in (approximate) historical order Not listed above: (some of) The Presocratics Epicus and logicianThe article titled Logicians treats the ancient Chinese philosophers known by that name (with a capital "L"). List of logicians (with a lower-case "l") treats philosophers, mathematicians, and others whose topic of scholarly study is logic.s have proposed.

• The correspondence theory of truthThe correspondence theory of truth is the theory that something is rendered true by the existence of a fact with corresponding elements and a similar structure. A rejection of any sort of relativism about truth, the correspondence theory maintains that th sees truth as correspondence with objective reality. Thus, a statement is said to be true just in case it expresses a state of affairs in the world.
• The coherence theoryCoherentism is belief in the coherence theory of justification — an epistemological theory opposing foundationalism and offering a solution to the regress argument. In this epistemological capacity, it is a theory about how belief can be justified. Cohere sees truth as coherence with some specified set of statements. Usually the set is identified as the statements that make up what is the best justified and most complete description of the world.
• The consensus theoryThe consensus theory of truth, originated by Charles Sanders Peirce who called it pragmatism and later pragmaticism holds that a statement is true if it would be agreed to by all those who investigate it. Consequence Note that, since it is possible in pri, invented by Charles Sanders Peirce sees truth as something agreed upon by some specified group, such as all competent investigators.
• PragmatismThe pragmatic theory of truth is a philosophical theory of truth. The theory states that something is true only if it is useful to believe. James's version of pragmatism was been taken up by later philosophers such as John Dewey and, most controversially, sees truth as the success of the practical consequences of an idea, i.e. its utility.
• Social constructivism holds that truth is constructed by social processes, and it represents the power struggles within a community.

Each can be interpreted as either a definition of the fundamental nature of truth, or as a criterion for determining truth values. So, for instance, a realist might define truth as correspondence with the facts, and argue that the only valid way to determine the truth of a proposition is to see if it corresponds to the facts. A Coherentist might also define truth as correspondence with mind-independent reality, but also maintain that the truth or falsity of a statement is determined by its cohering with the body of accepted scientific knowledge. Pierce in his later writings thought that truth was defined as correspondence with reality, but held that the truth or falsity of a proposal was determined by the agreement of the relevant experts.

The semantic theory of truth has as its general case for a given language:

'P' is true if and only if P

where 'P' is a reference to the sentence (the sentence's name), and P is just the sentence itself. As its inventor, philosopher-logician Alfred Tarski, acknowledged, the semantic theory cannot be applied to any natural language, such as English. One reason for this is that, when accurately and fully expressed, the semantic theory requires that each predicate in a language must have its satisfaction conditions specified separately. Since natural languages have an infinite number of predicates, a semantic theory of truth can never be actually expressed for a natural language.

Tarski thought of his theory as a species of correspondence theory, in which the term on the right is assumed to correspond to the facts.

Deflationary theories, after Gottlob Frege and F. P. Ramsey, also allege that "truth" is not the name of some property of propositions — some thing about which one could have a theory. The belief that truth is a property is just an illusion caused by the fact that we have the predicate "is true" in our language. Since most predicates name properties, we naturally assume that "is true" does as well. But, deflationists say, statements that seem to predicate truth actually do nothing more than signal agreement with the statement. For example, the redundancy theory of truth holds that to assert that a statement is true is just to assert the statement itself. Thus, to say that "Snow is white" is true is to say nothing more nor less than that show is white. A second example is the performative theory of truth which holds that to say "Snow is white" is true is to perform the speech act of signalling one's agreement with the claim that snow is white (much like nodding one's head in agreement). The idea that some statements are more actions than communicative statements is not as odd as it may seem. Consider, for example, that when the bride says "I do" at the appropriate time in a wedding, she is performing the act of taking this man to be her lawful wedded husband. She is not describing herself as taking this man. A third type of deflationary theory is the disquotational theory which uses a variant form of Tarski's schema: To say that '"P" is true' is to say that P.