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Truth is a concept of primary importance to philosophy,
science, law, and religion. Various senses in which the term truth have been used are described below.
To tell the truth at law
Witnesses who swear under oath to testify truthfully in courts of law, are not expected to make infallibly true statements, but to
make a good faith attempt to recount an observed event from their memory or provide expert testimony. That what one witness says may differ from true accounts of other witnesses is a
commonplace occurrence in the practice of law. Triers-of-fact are then charged with the responsibility to determine the
credibility or veracity of a witness' testimony.
Theories of truth
The study of truth is part of philosophical logic, but has
historically been of special interest to epistemologists. Sentences, propositions, statements, ideas, beliefs, and judgments can be true, and are called truth
bearers by philosophers. There are several broad theories about
truth that philosophers and logicians have proposed:
- The correspondence theory of truth
defines 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 theory of truth (which should not be confused with the coherence theory of justification) defines 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 theory, invented by Charles Sanders Peirce defines truth as something agreed upon
by some specified group, such as all competent investigators.
- Pragmatism defines truth as the success of
the practical consequences of an idea, i.e. its utility.
Note that virtually all non-correspondence theorists of truth reject ontological
realism, the notion that reality is a mind-independent thing. The world, they would say, is the creation of our collective
minds. (This is often, but not always, joined to the 19th century Idealist doctrine
that each of our minds is but a subset of a single all-encompassing mind called variously, the World Soul, the Absolute, or God.)
The fact that non-correspondence theories of truth are usually married to non-realist ontologies is crucial to understanding the
what their advocates have in mind. If one were to conjoin one of these non-correspondence theories of truth to a realist
ontology; that is, if we assume for the sake of argument that reality is mind-independent, then all of the non-correspondence
theories would open at least the possibility that reality and truth might somehow diverge. They imply that it is possible in
principle for "The interior of Venus is molten copper" to be true even if (as a matter of mind-independent fact) the interior of
Venus is not molten copper.
This result arises because only the non-correspondence theories make each proposition's truth value a matter of its relation
to something other than the mind-independent facts. E.g. the coherence theory makes each proposition's truth value a matter of
its relations with other propositions. So the truth value of "The interior of Venus is molten copper" is defined in
terms of its relations with other propositions, not in terms of its relations with interior of Venus.
But a non-realist ontology denies that there is any mind-independent thing called Venus in the first place. Venus, like the
rest of reality, is a creation of our minds. Moreover, a coherence theorist would insist, the world we create is largely a
function of which propositions best cohere with one another; hence, it is not possible for the coherent set that constitutes
reality to diverge from the coherent set that constitutes the truth.
Also, worth mentioning is the semantic theory of
truth which was classed by its inventor, philosopher-logician Alfred
Tarski, as a species of correspondence theory, but which others have classed as a species of deflationary theory (see below).
It can only be applied to languages with a finite number of sentences because it actually defines truth individually for every
sentence. For example, if "Snow is white" is one of the finite number of sentences in a particular language, then one
clause of the semantic theory would read "Snow is white" is true, if and only if, snow is white. Since natural
languages, such as English, have an infinite number of sentences, the semantic theory cannot be used to define truth for them.
The semantic theory is mainly of interest to scholars of certain artificial languages which have a finite number of sentences,
such as the language of set theory and its symbols. Tarski's theory enables such languages to escape what has been called the
Liar Paradox.
Theories of Truth Ascriptions
Many philosophers in the last 100 years have rejected the very idea of a theory of truth. "Truth", they claim, 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, in fact, they say, statements that seem to predicate
truth are actually doing something else entirely. This viewpoint is called deflationism or the deflationary theory of truth.
Deflationists offer theories, not of what truth is, but of what we are doing when we seem to ascribe truth to beliefs,
statements, propositions, etc. They offer theories of truth ascriptions, not theories of truth. (Hence, the term "deflationary
theory of truth" is misleading.) The redundancy theory of truth will serve as an example of a deflationary theory. According to it,
to assert that a statement is true is just to assert the statement itself. Thus, to say that "It is true that snow is white" 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 "It is true that snow is white" is to perform the action 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
... etc.
Truth in logic
Subjective, objective, relative and absolute truth
Subjective truths are those with which we are most intimately acquainted. That I like broccoli or that I have a pain in my foot are both subjectively true.
Metaphysical subjectivism holds that all we have
are such truths.
Objective truths are supposedly truths that are in some way independent of
our beliefs and tastes. However, this does not necessarily mean that objective truths are observable or verifiable. Believers in objective truth would class "The interior of Venus is molten copper" as
an objective truth, although it is not verifiable given present technology. More intriguingly, "Subatomic particle A is at
position X moving at speed S" would also count as an objective truth, but as Werner Heisenberg discovered, it cannot ever be verified, even in principle.
Relative truths are statements or propositions that are true only relative to some standard. Usually the standard cited is the
tenets of one's own culture. Since beliefs vary from culture-to-culture and era-to-era, relativism entails that what is true (not
merely what is believed) varies across cultures and eras. Relativism
is the doctrine that all truths are of this form. Its logical structure is dealt with in the article on the relativist fallacy. Moral relativism is the view that moral truths are socially determined. Subjectivism refers to an extreme form of relativism, in which all truth is held to be relative to the
individual.
Absolute truths, for example: God is truth; I am the way, the truth and the light; Allahu Akbar are truths that are supposed to emanate from the very essence of
the universe or God. As such they transcend human understanding, and are therefore unfortunately not subject to rational
criticism. Surprisingly, one cannot find Absolute truth in the Wikipedia.
Other semantic uses
One can distinguish two uses for the word true. The first is most often applied to people, and is used as a commendation,
synonymous (or nearly synonymous) with "loyal", as in she is true to her friends. The second has as its subject what has been called propositional content, as in it is true that the world is a sphere, and is
used as an assertion. Most of the discussion in this article relates to truth as used in an assertion.
Quotations
- "To say of what is, that it is, or of what is not, that it is not, is true." — Aristotle in Metaphysics (Book 4)
- "Truth - Something somehow discreditable to someone." — H.L.
Mencken
- "Truth exists - only lies are invented." — Georges
Braque
- "To me, truth is not some vague, foggy notion. Truth is real. And, at the same time, unreal. Fiction and
fact and everything in between, plus some things I can't remember, all rolled into one big 'thing'. This is truth, to
me." — Jack Handey
- "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the
truth." — Sherlock Holmes in "A Scandal in Bohemia" by Sir
Arthur Conan Doyle
- "What is truth?" — Pontius Pilate, the Gospel of John.
- "I am the truth and the light none come unto the Father except by me." — Jesus Christ
- "One of the grand fundamental principles of Mormonism is to receive
truth, let it come from whence it may . . . We should gather all the good and true principles in the world and
treasure them up, or we shall not come out true Mormons." — Joseph Smith, Jr.
- "What is truth? said jesting Pilate, but would not stay for an answer" — Francis Bacon, Essays 1: Of Truth
Major philosophers who have worked with theories of truth
See also
References
- Blackburn, S and Simmons K. 1999. Truth. Oxford University Press. A good anthology of classic articles, including
papers by James, Russell, Ramsey, Tarski and more recent work.
- Field, H. 2001. Truth and the Absence of Fact. Oxford.
- Horwich, P. Truth. Oxford.
- Habermas, Jürgen. 2003. Truth and Justification. MIT Press.
- Kirkham, Richard 1992: Theories of Truth. Bradford Books. A very good reference book.
- http://www.ditext.com/tarski/tarski.html Tarski's classic 1944 paper on the
Semantic Conception of Truth online.
- Williams, Bernard. 2002. Truth & Truthfulness: an essay in genealogy. Princeton University Press
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