A diverse and varied collection of philosophical
theories,
methodologies, and
inquiries seeking to answer this family of questions "What is
truth?", "What
makes true beliefs true"?, "What is the
difference between truth and
falsity?", "How do we
know true sentences are true?", etc. etc..
Most theories of truth attempt to provide answers to these questions and related questions, including: "What sort of
things (or
ontological entities) can be true (and false)?", "Is truth
objective,
subjective, or
relativistic?", "Is truth knowable?", "Is truth
divine,
occult, or
natural?", etc. etc..
There are almost as many theories of truth as there are
schools of philosophy. The most popular theories of truth advanced by philosophers in the
Western tradition are these, including some of the famous philosophers who were instrumental in their development:
- Correspondence Theory (Plato, Aristotle, Immanuel Kant, Ludwig Wittgenstein (early)) -- in which the general claim is that a sentence 'P' is true if and only if that sentence corresponds to a fact or state of affairs P that exists)
- Semantic Theory of Truth (Alfred Tarski, Donald Davidson) -- in which truth is formally defined as a semantic property of sentences, its definition generally being a sentence 'P' is true if and only if P, the semantic theory succeeds the correspondence theory in basically re-stating that truth is a function of correspondence, but without carrying the extra conceptual baggage of "facts" and "correspondence" that the correspondence theory relies upon
- Coherence Theory of Truth (Baruch Spinoza, Otto Neurath, Hilary Putnam) -- in which truth is a relational property held amongst a wide range of sentences, so that the truth of a sentence 'P' is accounted for in terms of the truth and falsity of other sentences in the language in which 'P' stands in a certain relation.
Sometimes classified as a subset of these theories are also Postmodernist Theories of Truth including sociological (Bloor), simulacrul (Baudrillard, DeBord), differential (Lyotard), and genealogical (Nietzsche, Foucault) analyses -- generally these theories of truth focus less on the nature of truth and more on the function of truth in human lives (see the paragraph below).
- Pragmatic Theory of Turth (Charles Sanders Peirce, William James, Richard Rorty) -- in which truth is defined in terms of practical success or the utility of beliesf. Like the postmodernist theories named above, pragmatism is often also seen as working against the traditional theories of truth.
- Deflationary Theories of Truth (Gottlob Frege, Paul Horwich) -- generally acknowledge that 'The sentence 'P' is true' is equivalent to asserting that P and are sometimes called disquotational or minimalist theories of truth because, in short, truth is a redundant property in our language.
Although I have included names like
Friedrich Nietzsche,
Michel Foucault, and
Richard Rorty on the above
topography, it can also be argued that their conceptions of truth do not approach the 'theories' proferred by the
epistemologists and
analytic philosophers populating the nearby geographies. In addition to the trend in philosophy that contemplates the
nature or
essence of truth, there is also the trend that argues that truth has no nature, it is varied, and mixed. Foucault, for example, tries to historicize truth and treat it as another concept that can be traded back and forth in exchanges of power. Rorty, on the other hand, tries to tie truth to the complex human practices and discourses in which it makes its appearance, thereby eliminating the
redundant extrapractical theory that philosophy may produce.