The opposite of truth is falsehood, which, correspondingly, can also take on a logical, factual, or ethical meaning. The concept of truth is discussed and debated in several contexts, including philosophy and religion. Many human activities depend upon the concept, which is assumed rather than a subject of discussion, including science, law, and everyday life.
Various theories and views of truth continue to be debated among scholars and philosophers. Language and words are a means by which humans convey information to one another and the method used to recognize a “truth” is termed a criterion of truth. There are differing claims on such questions as what constitutes truth: what things are truthbearers capable of being true or false; how to define and identify truth; the roles that revealed and acquired knowledge play; and whether truth is subjective or objective, relative or absolute.
Nomenclature, orthography, and etymology
The English word truth is from Old English tríewþ, tréowþ, trýwþ, Middle English trewþe, cognate to Old High German triuwida, Old Norse tryggð. Like troth, it is a -th nominalisation of the adjective true (Old English tréowe).
The English word true is from Old English (West Saxon) (ge)tríewe, tréowe, cognate to Old Saxon (gi)trûui, Old High German (ga)triuwu (Modern German treu “faithful”), Old Norse tryggr, Gothic triggws, all from a Proto-Germanic *trewwj- “having good faith“. Old Norse trú, “faith, word of honour; religious faith, belief” (archaic English troth “loyalty, honesty, good faith”, compare Ásatrú).
Thus, ‘truth’ involves both the quality of “faithfulness, fidelity, loyalty, sincerity, veracity”, and that of “agreement with fact or reality“, in Anglo-Saxon expressed by sōþ (Modern English sooth).
All Germanic languages besides English have introduced a terminological distinction between truth “fidelity” and truth “factuality”. To express “factuality”, North Germanic opted for nouns derived from sanna “to assert, affirm”, while continental West Germanic (German and Dutch) opted for continuations of wâra “faith, trust, pact” (cognate to Slavic věra “(religious) faith”, but influenced by Latin verus). Romance languages use terms following the Latin veritas, while the Greek aletheia, Russian pravda and Serbian istina have separate etymological origins.
Major theories of truth
The question of what is a proper basis for deciding how words, symbols, ideas and beliefs may properly be considered true, whether by a single person or an entire society, is dealt with by the five major substantive theories introduced below. Each theory presents perspectives that are widely shared by published scholars. There also have more recently arisen “deflationary” or “minimalist” theories of truth based on the idea that the application of a term like true to a statement does not assert anything significant about it, for instance, anything about its nature, but that the label truth is a tool of discourse used to express agreement, to emphasize claims, or to form certain types of generalizations.
Correspondence theories state that true beliefs and true statements correspond to the actual state of affairs. This type of theory posits a relationship between thoughts or statements on one hand, and things or objects on the other. It is a traditional model which goes back at least to some of the classical Greek philosophers such as Socrates, Plato, and Aristotle. This class of theories holds that the truth or the falsity of a representation is determined in principle solely by how it relates to “things”, by whether it accurately describes those “things”. An example of correspondence theory is the statement by the Thirteenth Century philosopher/theologian Thomas Aquinas: Veritas est adaequatio rei et intellectus (“Truth is the equation [or adequation] of things and intellect”), a statement which Aquinas attributed to the Ninth Century neoplatonist Isaac Israeli. Aquinas also restated the theory as: “A judgment is said to be true when it conforms to the external reality”
Correspondence theory practically operates on the assumption that truth is a matter of accurately copying what was much later called “objective reality” and then representing it in thoughts, words and other symbols. Many modern theorists have stated that this ideal cannot be achieved independently of some analysis of additional factors. For example, language plays a role in that all languages have words that are not easily translatable into another. The German word Zeitgeist is one such example: one who speaks or understands the language may “know” what it means, but any translation of the word apparently fails to accurately capture its full meaning (this is a problem with many abstract words, especially those derived in agglutinative languages). Thus, some words add an additional parameter to the construction of an accurate truth predicate. Among the philosophers who grappled with this problem is Alfred Tarski, whose semantic theory is summarized further below in this article.
Proponents of several of the theories below have gone further to assert that there are yet other issues necessary to the analysis, such as interpersonal power struggles, community interactions, personal biases and other factors involved in deciding what is seen as truth.
For coherence theories in general, truth requires a proper fit of elements within a whole system. Very often, though, coherence is taken to imply something more than simple logical consistency; often there is a demand that the propositions in a coherent system lend mutual inferential support to each other. So, for example, the completeness and comprehensiveness of the underlying set of concepts is a critical factor in judging the validity and usefulness of a coherent system. A pervasive tenet of coherence theories is the idea that truth is primarily a property of whole systems of propositions, and can be ascribed to individual propositions only according to their coherence with the whole. Among the assortment of perspectives commonly regarded as coherence theory, theorists differ on the question of whether coherence entails many possible true systems of thought or only a single absolute system.
Some variants of coherence theory are claimed to characterize the essential and intrinsic properties of formal systems in logic and mathematics. However, formal reasoners are content to contemplate axiomatically independent and sometimes mutually contradictory systems side by side, for example, the various alternative geometries. On the whole, coherence theories have been criticized as lacking justification in their application to other areas of truth, especially with respect to assertions about the natural world, empirical data in general, assertions about practical matters of psychology and society, especially when used without support from the other major theories of truth.
Coherence theories distinguish the thought of rationalist philosophers, particularly of Spinoza, Leibniz, and G.W.F. Hegel, along with the British philosopher F.H. Bradley. They have found a resurgence also among several proponents of logical positivism, notably Otto Neurath and Carl Hempel.
Social constructivism holds that truth is constructed by social processes, is historically and culturally specific, and that it is in part shaped through the power struggles within a community. Constructivism views all of our knowledge as “constructed,” because it does not reflect any external “transcendent” realities (as a pure correspondence theory might hold). Rather, perceptions of truth are viewed as contingent on convention, human perception, and social experience. It is believed by constructivists that representations of physical and biological reality, including race, sexuality, and gender, are socially constructed.
Giambattista Vico was among the first to claim that history and culture were man-made. Vico’s epistemological orientation gathers the most diverse rays and unfolds in one axiom – verum ipsum factum – “truth itself is constructed”. Hegel and Marx were among the other early proponents of the premise that truth is, or can be, socially constructed. Marx, like many critical theorists who followed, did not reject the existence of objective truth but rather distinguished between true knowledge and knowledge that has been distorted through power or ideology. For Marx scientific and true knowledge is ‘in accordance with the dialectical understanding of history’ and ideological knowledge ‘an epiphenomenal expression of the relation of material forces in a given economic arrangement’.
Consensus theory holds that truth is whatever is agreed upon, or in some versions, might come to be agreed upon, by some specified group. Such a group might include all human beings, or a subset thereof consisting of more than one person.
Among the current advocates of consensus theory as a useful accounting of the concept of “truth” is the philosopher Jürgen Habermas. Habermas maintains that truth is what would be agreed upon in an ideal speech situation. Among the current strong critics of consensus theory is the philosopher Nicholas Rescher.
The three most influential forms of the pragmatic theory of truth were introduced around the turn of the 20th century by Charles Sanders Peirce, William James, and John Dewey. Although there are wide differences in viewpoint among these and other proponents of pragmatic theory, they hold in common that truth is verified and confirmed by the results of putting one’s concepts into practice.
Peirce defines truth as follows: “Truth is that concordance of an abstract statement with the ideal limit towards which endless investigation would tend to bring scientific belief, which concordance the abstract statement may possess by virtue of the confession of its inaccuracy and one-sidedness, and this confession is an essential ingredient of truth.” This statement emphasizes Peirce’s view that ideas of approximation, incompleteness, and partiality, what he describes elsewhere as fallibilism and “reference to the future”, are essential to a proper conception of truth. Although Peirce uses words like concordance and correspondence to describe one aspect of the pragmatic sign relation, he is also quite explicit in saying that definitions of truth based on mere correspondence are no more than nominal definitions, which he accords a lower status than real definitions.
William James’s version of pragmatic theory, while complex, is often summarized by his statement that “the ‘true’ is only the expedient in our way of thinking, just as the ‘right’ is only the expedient in our way of behaving.” By this, James meant that truth is a quality, the value of which is confirmed by its effectiveness when applying concepts to practice (thus, “pragmatic”).
John Dewey, less broadly than James but more broadly than Peirce, held that inquiry, whether scientific, technical, sociological, philosophical or cultural, is self-corrective over time if openly submitted for testing by a community of inquirers in order to clarify, justify, refine and/or refute proposed truths.
Though not widely publicized, a new variation of the pragmatic theory was defined and wielded successfully from the 20th century forward. Defined and named by William Ernest Hocking, this variation is known as “negative pragmatism”. Essentially, what works may or may not be true, but what fails cannot be true because the truth always works. Richard Feynman also ascribed to it: “We never are definitely right, we can only be sure we are wrong.” This approach incorporates many of the ideas from Peirce, James, and Dewey. For Peirce, the idea of “… endless investigation would tend to bring about scientific belief …” fits negative pragmatism in that a negative pragmatist would never stop testing. As Feynman noted, an idea or theory “… could never be proved right, because tomorrow’s experiment might succeed in proving wrong what you thought was right.” Similarly, James and Dewey’s ideas also ascribe to repeated testing which is “self-corrective” over time.
Pragmatism and negative pragmatism are also closely aligned with the coherence theory of truth in that any testing should not be isolated but rather incorporate knowledge from all human endeavors and experience. The universe is a whole and integrated system, and testing should recognize and account for its diversity. As Feynman said, “… if it disagrees with experiment, it is wrong.”
Minimalist (deflationary) theories
Some philosophers reject the thesis that the concept or term truth refers to a real property of sentences or propositions. These philosophers are responding, in part, to the common use of truth predicates (e.g., that some particular thing “…is true”) which was particularly prevalent in philosophical discourse on truth in the first half of the 20th century. From this point of view, to assert the proposition “‘2 + 2 = 4’ is true” is logically equivalent to asserting the proposition “2 + 2 = 4”, and the phrase “is true” is completely dispensable in this and every other context. These positions are broadly described
- as deflationary theories of truth, since they attempt to deflate the presumed importance of the words “true” or truth,
- as disquotational theories, to draw attention to the disappearance of the quotation marks in cases like the above example, or
- as minimalist theories of truth.
Whichever term is used, deflationary theories can be said to hold in common that “[t]he predicate ‘true’ is an expressive convenience, not the name of a property requiring deep analysis.” Once we have identified the truth predicate’s formal features and utility, deflationists argue, we have said all there is to be said about truth. Among the theoretical concerns of these views is to explain away those special cases where it does appear that the concept of truth has peculiar and interesting properties. (See, e.g., Semantic paradoxes, and below.)
In addition to highlighting such formal aspects of the predicate “is true”, some deflationists point out that the concept enables us to express things that might otherwise require infinitely long sentences. For example, one cannot express confidence in Michael’s accuracy by asserting the endless sentence:
- Michael says, ‘snow is white’ and snow is white, or he says ‘roses are red’ and roses are red or he says … etc.
This assertion can also be succinctly expressed by saying: What Michael says is true.
Performative theory of truth
Attributed to P. F. Strawson is the performative theory of truth which holds that to say “‘Snow is white’ is true” is to perform the speech act of signaling 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, but actually doing so (perhaps the most thorough analysis of such “illocutionary acts” is J. L. Austin, “How to Do Things With Words“).
Strawson holds that a similar analysis is applicable to all speech acts, not just illocutionary ones: “To say a statement is true is not to make a statement about a statement, but rather to perform the act of agreeing with, accepting, or endorsing a statement. When one says ‘It’s true that it’s raining,’ one asserts no more than ‘It’s raining.’ The function of [the statement] ‘It’s true that…’ is to agree with, accept, or endorse the statement that ‘it’s raining.'”
Redundancy and related theories
According to the redundancy theory of truth, asserting that a statement is true is completely equivalent to asserting the statement itself. For example, making the assertion that ” ‘Snow is white’ is true” is equivalent to asserting “Snow is white”. Redundancy theorists infer from this premise that truth is a redundant concept; that is, it is merely a word that is traditionally used in conversation or writing, generally for emphasis, but not a word that actually equates to anything in reality. This theory is commonly attributed to Frank P. Ramsey, who held that the use of words like fact and truth was nothing but a roundabout way of asserting a proposition, and that treating these words as separate problems in isolation from judgment was merely a “linguistic muddle”.
A variant of redundancy theory is the disquotational theory which uses a modified form of Tarski‘s schema: To say that ‘”P” is true’ is to say that P. A version of this theory was defended by C. J. F. Williams in his book What is Truth?. Yet another version of deflationism is the prosentential theory of truth, first developed by Dorothy Grover, Joseph Camp, and Nuel Belnap as an elaboration of Ramsey’s claims. They argue that sentences like “That’s true”, when said in response to “It’s raining”, are prosentences, expressions that merely repeat the content of other expressions. In the same way that it means the same as my dog in the sentence My dog was hungry, so I fed it, That’s true is supposed to mean the same as It’s raining — if you say the latter and I then say the former. These variations do not necessarily follow Ramsey in asserting that truth is not a property, but rather can be understood to say that, for instance, the assertion “P” may well involve a substantial truth, and the theorists in this case are minimalizing only the redundancy or prosentence involved in the statement such as “that’s true.”
Deflationary principles do not apply to representations that are not analogous to sentences, and also do not apply to many other things that are commonly judged to be true or otherwise. Consider the analogy between the sentence “Snow is white” and the character named Snow White, both of which can be true in some sense. To a minimalist, saying “Snow is white is true” is the same as saying “Snow is white,” but to say “Snow White is true” is not the same as saying “Snow White.”
Several of the major theories of truth hold that there is a particular property the having of which makes a belief or proposition true. Pluralist theories of truth assert that there may be more than one property that makes propositions true: ethical propositions might be true by virtue of coherence. Propositions about the physical world might be true by corresponding to the objects and properties they are about.
Some of the pragmatic theories, such as those by Charles Peirce and William James, included aspects of correspondence, coherence and constructivist theories. Crispin Wright argued in his 1992 book Truth and Objectivity that any predicate which satisfied certain platitudes about truth qualified as a truth predicate. In some discourses, Wright argued, the role of the truth predicate might be played by the notion of superassertibility. Michael Lynch, in a 2009 book Truth as One and Many, argued that we should see truth as a functional property capable of being multiply manifested in distinct properties like correspondence or coherence.
Most believed theories
According to a survey of professional philosophers and others on their philosophical views which was carried out in November 2009 (taken by 3226 respondents, including 1803 philosophy faculty members and/or PhDs and 829 philosophy graduate students) 44.9% of respondents accept or lean towards correspondence theories, 20.7% accept or lean towards deflationary theories and 13.8% epistemic theories.
Truth in logic
Logic is concerned with the patterns in reason that can help tell us if a proposition is true or not. However, logic does not deal with truth in the absolute sense, as for instance a metaphysician does. Logicians use formal languages to express the truths which they are concerned with, and as such there is only truth under some interpretation or truth within some logical system.
A logical truth (also called an analytic truth or a necessary truth) is a statement which is true in all possible worlds or under all possible interpretations, as contrasted to a fact (also called a synthetic claim or a contingency) which is only true in this world as it has historically unfolded. A proposition such as “If p and q, then p.” is considered to be logical truth because it is true because of the meaning of the symbols and words in it and not because of any facts of any particular world. They are such that they could not be untrue.
Truth in mathematics
Historically, with the nineteenth century development of Boolean algebra mathematical models of logic began to treat “truth”, also represented as “T” or “1”, as an arbitrary constant. “Falsity” is also an arbitrary constant, which can be represented as “F” or “0”. In propositional logic, these symbols can be manipulated according to a set of axioms and rules of inference, often given in the form of truth tables.
In addition, from at least the time of Hilbert’s program at the turn of the twentieth century to the proof of Gödel’s incompleteness theorems and the development of the Church-Turing thesis in the early part of that century, true statements in mathematics were generally assumed to be those statements which are provable in a formal axiomatic system.
The works of Kurt Gödel, Alan Turing, and others shook this assumption, with the development of statements that are true but cannot be proven within the system. Two examples of the latter can be found in Hilbert’s problems. Work on Hilbert’s 10th problem led in the late twentieth century to the construction of specific Diophantine equations for which it is undecidable whether they have a solution, or even if they do, whether they have a finite or infinite number of solutions. More fundamentally, Hilbert’s first problem was on the continuum hypothesis. Gödel and Paul Cohen showed that this hypothesis cannot be proved or disproved using the standard axioms of set theory. In the view of some, then, it is equally reasonable to take either the continuum hypothesis or its negation as a new axiom.
Semantic theory of truth
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.
Logician and philosopher Alfred Tarski developed the theory for formal languages (such as formal logic). Here he restricted it in this way: no language could contain its own truth predicate, that is, the expression is true could only apply to sentences in some other language. The latter he called an object language, the language being talked about. (It may, in turn, have a truth predicate that can be applied to sentences in still another language.) The reason for his restriction was that languages that contain their own truth predicate will contain paradoxical sentences such as, “This sentence is not true”. As a result Tarski held that the semantic theory could not be applied to any natural language, such as English, because they contain their own truth predicates. Donald Davidson used it as the foundation of his truth-conditional semantics and linked it to radical interpretation in a form of coherentism.
Bertrand Russell is credited with noticing the existence of such paradoxes even in the best symbolic formalizations of mathematics in his day, in particular the paradox that came to be named after him, Russell’s paradox. Russell and Whitehead attempted to solve these problems in Principia Mathematica by putting statements into a hierarchy of types, wherein a statement cannot refer to itself, but only to statements lower in the hierarchy. This in turn led to new orders of difficulty regarding the precise natures of types and the structures of conceptually possible type systems that have yet to be resolved to this day.
Kripke’s theory of truth
Saul Kripke contends that a natural language can in fact contain its own truth predicate without giving rise to contradiction. He showed how to construct one as follows:
- Begin with a subset of sentences of a natural language that contains no occurrences of the expression “is true” (or “is false”). So The barn is big is included in the subset, but not ” The barn is big is true”, nor problematic sentences such as “This sentence is false”.
- Define truth just for the sentences in that subset.
- Then extend the definition of truth to include sentences that predicate truth or falsity of one of the original subset of sentences. So “The barn is big is true” is now included, but not either “This sentence is false” nor “‘The barn is big is true’ is true”.
- Next, define truth for all sentences that predicate truth or falsity of a member of the second set. Imagine this process repeated infinitely, so that truth is defined for The barn is big; then for “The barn is big is true”; then for “‘The barn is big is true’ is true”, and so on.
Notice that truth never gets defined for sentences like This sentence is false, since it was not in the original subset and does not predicate truth of any sentence in the original or any subsequent set. In Kripke’s terms, these are “ungrounded.” Since these sentences are never assigned either truth or falsehood even if the process is carried out infinitely, Kripke’s theory implies that some sentences are neither true nor false. This contradicts the Principle of bivalence: every sentence must be either true or false. Since this principle is a key premise in deriving the Liar paradox, the paradox is dissolved.
However, it has been shown by Gödel that self-reference cannot be avoided naively, since propositions about seemingly unrelated objects can have an informal self-referential meaning; in Gödel’s work, these objects are integer numbers, and they have an informal meaning regarding propositions. In fact, this idea – manifested by the diagonal lemma – is the basis for Tarski’s theorem that truth cannot be consistently defined.
It has thus been claimed  that Kripke’s system indeed leads to contradiction: while its truth predicate is only partial, it does give truth value (true/false) to propositions such as the one built in Tarski’s proof, and is therefore inconsistent. While there is still a debate on whether Tarski’s proof can be implemented to every similar partial truth system, none have been shown to be consistent by acceptable methods used in mathematical logic.
The ancient Greek origins of the words “true” and “truth” have some consistent definitions throughout great spans of history that were often associated with topics of logic, geometry, mathematics, deduction, induction, and natural philosophy.
Socrates’, Plato’s and Aristotle’s ideas about truth are commonly seen as consistent with correspondence theory. In his Metaphysics, Aristotle stated: “To say of what is that it is not, or of what is not that it is, is false, while to say of what is that it is, and of what is not that it is not, is true”. The Stanford Encyclopedia of Philosophy proceeds to say of Aristotle:
“(…) Aristotle sounds much more like a genuine correspondence theorist in the Categories (12b11, 14b14), where he talks of “underlying things” that make statements true and implies that these “things” (pragmata) are logically structured situations or facts (viz., his sitting, his not sitting). Most influential is his claim in De Interpretatione (16a3) that thoughts are “likenessess” (homoiosis) of things. Although he nowhere defines truth in terms of a thought’s likeness to a thing or fact, it is clear that such a definition would fit well into his overall philosophy of mind. (…)”
Very similar statements can also be found in Plato (Cratylus 385b2, Sophist 263b).
In Hinduism, Truth is defined as “unchangeable”, “that which has no distortion”, “that which is beyond distinctions of time, space, and person”, “that which pervades the universe in all its constancy”. Human body, therefore is not completely true as it changes with time, for example. There are many references, properties and explanations of truth by Hindu sages that explain varied facets of truth, such as “Satyam eva jayate” (Truth alone wins), “Satyam muktaye” (Truth liberates), “Satya’ is ‘Parahit’artham’ va’unmanaso yatha’rthatvam’ satyam” (Satya is the benevolent use of words and the mind for the welfare of others or in other words responsibilities is truth too), “When one is firmly established in speaking truth, the fruits of action become subservient to him ( patanjali yogasutras, sutra number 2.36 ), “The face of truth is covered by a golden bowl. Unveil it, O Pusan (Sun), so that I who have truth as my duty (satyadharma) may see it!” (Brhadaranyaka V 15 1-4 and the brief IIsa Upanisad 15-18), Truth is superior to silence (Manusmriti), etc. Combined with other words, satya acts as modifier, like “ultra” or “highest,” or more literally “truest,” connoting purity and excellence. For example, satyaloka is the “highest heaven’ and Satya Yuga is the “golden age” or best of the four cyclical cosmic ages in Hinduism, and so on.
“What corresponds in the mind to what is outside it.”
“The truth of a thing is the property of the being of each thing which has been established in it.”
However, this definition is merely a translation of the Latin translation from the Middle Ages. A modern translation of the original Arabic text states:
“Truth is also said of the veridical belief in the existence [of something]”.
Reevaluating Avicenna, and also Augustine and Aristotle, Thomas Aquinas stated in his Disputed Questions on Truth:
A natural thing, being placed between two intellects, is called true insofar as it conforms to either. It is said to be true with respect to its conformity with the divine intellect insofar as it fulfills the end to which it was ordained by the divine intellect… With respect to its conformity with a human intellect, a thing is said to be true insofar as it is such as to cause a true estimate about itself.
Thus, for Aquinas, the truth of the human intellect (logical truth) is based on the truth in things (ontological truth). Following this, he wrote an elegant re-statement of Aristotle’s view in his Summa I.16.1:
Veritas est adæquatio intellectus et rei.
(Truth is the conformity of the intellect to the things.)
Aquinas also said that real things participate in the act of being of the Creator God who is Subsistent Being, Intelligence, and Truth. Thus, these beings possess the light of intelligibility and are knowable. These things (beings; reality) are the foundation of the truth that is found in the human mind, when it acquires knowledge of things, first through the senses, then through the understanding and the judgement done by reason. For Aquinas, human intelligence (“intus”, within and “legere”, to read) has the capability to reach the essence and existence of things because it has a non-material, spiritual element, although some moral, educational, and other elements might interfere with its capability.
Changing concepts of truth in the Middle Ages
Richard Firth Green analyzed the concept of truth in the later Middle Ages in his A Crisis of Truth, and concludes that roughly during the reign of Richard II of England the very meaning of the concept changes. The idea of the oath, which was so much part and parcel of for instance Romance literature, changes from a subjective concept to a more objective one (in Derek Pearsall‘s summary). Whereas truth (the “trouthe” of Sir Gawain and the Green Knight) was first “an ethical truth in which truth is understood to reside in persons”, in Ricardian England it “transforms…into a political truth in which truth is understood to reside in documents”
Immanuel Kant endorses a definition of truth along the lines of the correspondence theory of truth. Kant writes in the Critique of Pure Reason: “The nominal definition of truth, namely that it is the agreement of cognition with its object, is here granted and presupposed”. However, Kant denies that this correspondence definition of truth provides us with a test or criterion to establish which judgements are true. Kant states in his logic lectures:
“(…) Truth, it is said, consists in the agreement of cognition with its object. In consequence of this mere nominal definition, my cognition, to count as true, is supposed to agree with its object. Now I can compare the object with my cognition, however, only by cognizing it. Hence my cognition is supposed to confirm itself, which is far short of being sufficient for truth. For since the object is outside me, the cognition in me, all I can ever pass judgement on is whether my cognition of the object agrees with my cognition of the object. The ancients called such a circle in explanation a diallelon. And actually the logicians were always reproached with this mistake by the sceptics, who observed that with this definition of truth it is just as when someone makes a statement before a court and in doing so appeals to a witness with whom no one is acquainted, but who wants to establish his credibility by maintaining that the one who called him as witness is an honest man. The accusation was grounded, too. Only the solution of the indicated problem is impossible without qualification and for every man. (…)”
This passage makes use of his distinction between nominal and real definitions. A nominal definition explains the meaning of a linguistic expression. A real definition describes the essence of certain objects and enable us to determine whether any given item falls within the definition. Kant holds that the definition of truth is merely nominal and, therefore, we cannot employ it to establish which judgements are true. According to Kant, the ancient skeptics criticized the logicians for holding that, by means of a merely nominal definition of truth, they can establish which judgements are true. They were trying to do something that is “impossible without qualification and for every man”.
Georg Hegel distanced his philosophy from psychology by presenting truth as being an external self-moving object instead of being related to inner, subjective thoughts. Hegel’s truth is analogous to the mechanics of a material body in motion under the influence of its own inner force. “Truth is its own self-movement within itself.” Teleological truth moves itself in the three-step form of dialectical triplicity toward the final goal of perfect, final, absolute truth. For Hegel, the progression of philosophical truth is a resolution of past oppositions into increasingly more accurate approximations to absolute truth. Chalybäus used the terms “thesis“, “antithesis“, and “synthesis” to describe Hegel’s dialectical triplicity. The “thesis” consists of an incomplete historical movement. To resolve the incompletion, an “antithesis” occurs which opposes the “thesis.” In turn, the “synthesis” appears when the “thesis” and “antithesis” become reconciled and a higher level of truth is obtained. This “synthesis” thereby becomes a “thesis,” which will again necessitate an “antithesis,” requiring a new “synthesis” until a final state is reached as the result of reason’s historical movement. History is the Absolute Spirit moving toward a goal. This historical progression will finally conclude itself when the Absolute Spirit understands its own infinite self at the very end of history. Absolute Spirit will then be the complete expression of an infinite God.
For Arthur Schopenhauer, a judgment is a combination or separation of two or more concepts. If a judgment is to be an expression of knowledge, it must have a sufficient reason or ground by which the judgment could be called true. Truth is the reference of a judgment to something different from itself which is its sufficient reason (ground). Judgments can have material, formal, transcendental, or metalogical truth. A judgment has material truth if its concepts are based on intuitive perceptions that are generated from sensations. If a judgment has its reason (ground) in another judgment, its truth is called logical or formal. If a judgment, of, for example, pure mathematics or pure science, is based on the forms (space, time, causality) of intuitive, empirical knowledge, then the judgment has transcendental truth.
When Søren Kierkegaard, as his character Johannes Climacus, ends his writings: My thesis was, subjectivity, heartfelt is the truth, he does not advocate for subjectivism in its extreme form (the theory that something is true simply because one believes it to be so), but rather that the objective approach to matters of personal truth cannot shed any light upon that which is most essential to a person’s life. Objective truths are concerned with the facts of a person’s being, while subjective truths are concerned with a person’s way of being. Kierkegaard agrees that objective truths for the study of subjects like mathematics, science, and history are relevant and necessary, but argues that objective truths do not shed any light on a person’s inner relationship to existence. At best, these truths can only provide a severely narrowed perspective that has little to do with one’s actual experience of life.
While objective truths are final and static, subjective truths are continuing and dynamic. The truth of one’s existence is a living, inward, and subjective experience that is always in the process of becoming. The values, morals, and spiritual approaches a person adopts, while not denying the existence of objective truths of those beliefs, can only become truly known when they have been inwardly appropriated through subjective experience. Thus, Kierkegaard criticizes all systematic philosophies which attempt to know life or the truth of existence via theories and objective knowledge about reality. As Kierkegaard claims, human truth is something that is continually occurring, and a human being cannot find truth separate from the subjective experience of one’s own existing, defined by the values and fundamental essence that consist of one’s way of life.
Friedrich Nietzsche believed the search for truth or ‘the will to truth’ was a consequence of the will to power of philosophers. He thought that truth should be used as long as it promoted life and the will to power, and he thought untruth was better than truth if it had this life enhancement as a consequence. As he wrote in Beyond Good and Evil, “The falseness of a judgment is to us not necessarily an objection to a judgment… The question is to what extent it is life-advancing, life-preserving, species-preserving, perhaps even species-breeding…” (aphorism 4). He proposed the will to power as a truth only because according to him it was the most life affirming and sincere perspective one could have.
Robert Wicks discusses Nietzsche’s basic view of truth as follows:
“(…) Some scholars regard Nietzsche’s 1873 unpublished essay, “On Truth and Lies in a Nonmoral Sense” (“Über Wahrheit und Lüge im außermoralischen Sinn”) as a keystone in his thought. In this essay, Nietzsche rejects the idea of universal constants, and claims that what we call “truth” is only “a mobile army of metaphors, metonyms, and anthropomorphisms.” His view at this time is that arbitrariness completely prevails within human experience: concepts originate via the very artistic transference of nerve stimuli into images; “truth” is nothing more than the invention of fixed conventions for merely practical purposes, especially those of repose, security and consistence. (…)”
Alfred North Whitehead, a British mathematician who became an American philosopher, said: “There are no whole truths; all truths are half-truths. It is trying to treat them as whole truths that play the devil”.
The logical progression or connection of this line of thought is to conclude that truth can lie, since half-truths are deceptive and may lead to a false conclusion.
According to Kitaro Nishida, “knowledge of things in the world begins with the differentiation of unitary consciousness into knower and known and ends with self and things becoming one again. Such unification takes form not only in knowing but in the valuing (of truth) that directs knowing, the willing that directs action, and the feeling or emotive reach that directs sensing.”
Erich Fromm finds that trying to discuss truth as “absolute truth” is sterile and that emphasis ought to be placed on “optimal truth”. He considers truth as stemming from the survival imperative of grasping one’s environment physically and intellectually, whereby young children instinctively seek truth so as to orient themselves in “a strange and powerful world”. The accuracy of their perceived approximation of the truth will therefore have direct consequences on their ability to deal with their environment. Fromm can be understood to define truth as a functional approximation of reality. His vision of optimal truth is described partly in “Man from Himself: An Inquiry into the Psychology of Ethics” (1947), from which excerpts are included below.
- the dichotomy between ‘absolute = perfect’ and ‘relative = imperfect’ has been superseded in all fields of scientific thought, where “it is generally recognized that there is no absolute truth but nevertheless that there are objectively valid laws and principles”.
- In that respect, “a scientifically or rationally valid statement means that the power of reason is applied to all the available data of observation without any of them being suppressed or falsified for the sake of a desired result”. The history of science is “a history of inadequate and incomplete statements, and every new insight makes possible the recognition of the inadequacies of previous propositions and offers a springboard for creating a more adequate formulation.”
- As a result “the history of thought is the history of an ever-increasing approximation to the truth. Scientific knowledge is not absolute but optimal; it contains the optimum of truth attainable in a given historical period.” Fromm furthermore notes that “different cultures have emphasized various aspects of the truth” and that increasing interaction between cultures allows for these aspects to reconcile and integrate, increasing further the approximation to the truth.
Truth, says Michel Foucault, is problematic when any attempt is made to see truth as an “objective” quality. He prefers not to use the term truth itself but “Regimes of Truth”. In his historical investigations he found truth to be something that was itself a part of, or embedded within, a given power structure. Thus Foucault’s view shares much in common with the concepts of Nietzsche. Truth for Foucault is also something that shifts through various episteme throughout history.
Jean Baudrillard considered truth to be largely simulated, that is pretending to have something, as opposed to dissimulation, pretending to not have something. He took his cue from iconoclasts who he claims knew that images of God demonstrated that God did not exist. Baudrillard wrote in “Precession of the Simulacra”:
Some examples of simulacra that Baudrillard cited were: that prisons simulate the “truth” that society is free; scandals (e.g., Watergate) simulate that corruption is corrected; Disney simulates that the U.S. itself is an adult place. One must remember that though such examples seem extreme, such extremity is an important part of Baudrillard’s theory. For a less extreme example, consider how movies usually end with the bad being punished, humiliated, or otherwise failing, thus affirming for viewers the concept that the good end happily and the bad unhappily, a narrative which implies that the status quo and institutionalised power structures are largely legitimate.
In medicine and psychiatry
In religion: omniscience
In a religious context, perfect knowledge of all truth about all things (omniscience) is regarded by some religions, particularly Buddhism and the Abrahamic religions (Christianity, Islam, and Judaism), as an attribute of a divine being. In the Abrahamic view, God can exercise divine judgment, judging the dead on the basis of perfect knowledge of their lives.
Belief is the psychological state in which an individual holds a proposition or premise to be true. Dispositional and occurrent belief concerns the contextual activation of the belief into thoughts (reactive of propositions) or ideas (based on the belief’s premise).
Belief, knowledge and epistemology
The terms belief and knowledge are used differently in philosophy.
Epistemology is the philosophical study of knowledge and belief. The primary problem in epistemology is to understand exactly what is needed in order for us to have true knowledge. In a notion derived from Plato‘s dialogue Theaetetus, philosophy has traditionally defined knowledge as “justified true belief“. The relationship between belief and knowledge is that a belief is knowledge if the belief is true, and if the believer has a justification (reasonable and necessarily plausible assertions/evidence/guidance) for believing it is true.
A false belief is not considered to be knowledge, even if it is sincere. A sincere believer in the flat earth theory does not know that the Earth is flat. Later epistemologists, for instance Gettier (1963) and Goldman (1967), have questioned the “justified true belief” definition.
Belief as a psychological theory
Mainstream psychology and related disciplines have traditionally treated belief as if it were the simplest form of mental representation and therefore one of the building blocks of conscious thought. Philosophers have tended to be more abstract in their analysis, and much of the work examining the viability of the belief concept stems from philosophical analysis.
The concept of belief presumes a subject (the believer) and an object of belief (the proposition). So, like other propositional attitudes, belief implies the existence of mental states and intentionality, both of which are hotly debated topics in the philosophy of mind, whose foundations and relation to brain states are still controversial.
Beliefs are sometimes divided into core beliefs (that are actively thought about) and dispositional beliefs (that may be ascribed to someone who has not thought about the issue). For example, if asked “do you believe tigers wear pink pajamas?” a person might answer that they do not, despite the fact they may never have thought about this situation before.
That a belief is a mental state has been seen by some as contentious. While some have argued that beliefs are represented in the mind as sentence-like constructs, others have gone as far as arguing that there is no consistent or coherent mental representation that underlies our common use of the belief concept and that it is therefore obsolete and should be rejected.
This has important implications for understanding the neuropsychology and neuroscience of belief. If the concept of belief is incoherent, then any attempt to find the underlying neural processes that support it will fail.
- Our common-sense understanding of belief is correct – Sometimes called the “mental sentence theory,” in this conception, beliefs exist as coherent entities, and the way we talk about them in everyday life is a valid basis for scientific endeavour. Jerry Fodor is one of the principal defenders of this point of view.
- Our common-sense understanding of belief may not be entirely correct, but it is close enough to make some useful predictions – This view argues that we will eventually reject the idea of belief as we use it now, but that there may be a correlation between what we take to be a belief when someone says “I believe that snow is white” and how a future theory of psychology will explain this behaviour. Most notably, philosopher Stephen Stich has argued for this particular understanding of belief.
- Our common-sense understanding of belief is entirely wrong and will be completely superseded by a radically different theory that will have no use for the concept of belief as we know it – Known as eliminativism, this view, (most notably proposed by Paul and Patricia Churchland), argues that the concept of belief is like obsolete theories of times past such as the four humours theory of medicine, or the phlogiston theory of combustion. In these cases science hasn’t provided us with a more detailed account of these theories, but completely rejected them as valid scientific concepts to be replaced by entirely different accounts. The Churchlands argue that our common-sense concept of belief is similar in that as we discover more about neuroscience and the brain, the inevitable conclusion will be to reject the belief hypothesis in its entirety.
- Our common-sense understanding of belief is entirely wrong; however, treating people, animals, and even computers as if they had beliefs is often a successful strategy – The major proponents of this view, Daniel Dennett and Lynne Rudder Baker, are both eliminativists in that they hold that beliefs are not a scientifically valid concept, but they don’t go as far as rejecting the concept of belief as a predictive device. Dennett gives the example of playing a computer at chess. While few people would agree that the computer held beliefs, treating the computer as if it did (e.g. that the computer believes that taking the opposition’s queen will give it a considerable advantage) is likely to be a successful and predictive strategy. In this understanding of belief, named by Dennett the intentional stance, belief-based explanations of mind and behaviour are at a different level of explanation and are not reducible to those based on fundamental neuroscience, although both may be explanatory at their own level.
How beliefs are formed
Psychologists study belief formation and the relationship between beliefs and actions. Beliefs form in a variety of ways:
- We tend to internalise the beliefs of the people around us during childhood. Albert Einstein is often quoted as having said that “Common sense is the collection of prejudices acquired by age eighteen.” Political beliefs depend most strongly on the political beliefs most common in the community where we live. Most individuals believe the religion they were taught in childhood.
- People may adopt the beliefs of a charismatic leader, even if those beliefs fly in the face of all previous beliefs, and produce actions that are clearly not in their own self-interest. Is belief voluntary? Rational individuals need to reconcile their direct reality with any said belief; therefore, if belief is not present or possible, it reflects the fact that contradictions were necessarily overcome using cognitive dissonance.
- Advertising can form or change beliefs through repetition, shock, and association with images of sex, love, beauty, and other strong positive emotions.
- Physical trauma, especially to the head, can radically alter a person’s beliefs.
However, even educated people, well aware of the process by which beliefs form, still strongly cling to their beliefs, and act on those beliefs even against their own self-interest. In Anna Rowley’s Leadership Theory, she states “You want your beliefs to change. It’s proof that you are keeping your eyes open, living fully, and welcoming everything that the world and people around you can teach you.” This means that peoples’ beliefs should evolve as they gain new experiences.
To “believe in” someone or something is a distinct concept from “believe-that.” There are two types of belief-in:
- Commendatory – an expression of confidence in a person or entity, as in, “I believe in his ability to do the job.”
- Existential claim – to claim belief in the existence of an entity or phenomenon with the implied need to justify its claim to existence. It is often used when the entity is not real, or its existence is in doubt. “He believes in witches and ghosts” or “many children believe in Santa Claus” are typical examples.
Delusions are defined as beliefs in psychiatric diagnostic criteria (for example in the Diagnostic and Statistical Manual of Mental Disorders). Psychiatrist and historian G.E. Berrios has challenged the view that delusions are genuine beliefs and instead labels them as “empty speech acts,” where affected persons are motivated to express false or bizarre belief statements due to an underlying psychological disturbance. However, the majority of mental health professionals and researchers treat delusions as if they were genuine beliefs.
In Lewis Carroll‘s Through the Looking-Glass the White Queen says, “Why, sometimes I’ve believed as many as six impossible things before breakfast.” This is often quoted in mockery of the common ability of people to entertain beliefs contrary to fact.
Theory of Justification
Theory of justification is a part of epistemology that attempts to understand the justification of propositions and beliefs. Epistemologists are concerned with various epistemic features of belief, which include the ideas of justification, warrant, rationality, and probability. Of these four terms, the term that has been most widely used and discussed by the early 21st century is “warrant”. Loosely speaking, justification is the reason that someone (properly) holds a belief.
If A makes a claim, and B then casts doubt on it, A’s next move would normally be to provide justification. Empiricism (the evidence of the senses), authoritative testimony (the appeal to criteria and authority), and logical deduction are often involved in justification.
Justification-based theories of knowledge can be divided into:
- irrationalism, which appeals to irrational criteria and authorities (such as feelings) and
- panrationalism, which appeals to rational criteria and authorities (such as observation or reasoning).
Subjects of justification
Many things can be justified: beliefs, actions, emotions, claims, laws, theories and so on. Epistemology focuses on beliefs. This is in part because of the influence of the definition of knowledge as “justified true belief” often associated with a theory discussed near the end of the Socratic dialogue Theaetetus. More generally, theories of justification focus on the justification of statements or propositions.
Justifications and explanations
Justification is the reason why someone properly holds a belief, the explanation as to why the belief is a true one, or an account of how one knows what one knows. In much the same way arguments and explanations may be confused with each other, as may explanations and justifications. Statements which are justifications of some action take the form of arguments. For example attempts to justify a theft usually explain the motives (e.g., to feed a starving family).
It is important to be aware when an explanation is not a justification. A criminal profiler may offer an explanation of a suspect’s behavior (e.g.; the person lost his or her job, the person got evicted, etc.), and such statements may help us understand why the person committed the crime. An uncritical listener may believe the speaker is trying to gain sympathy for the person and his or her actions, but it does not follow that a person proposing an explanation has any sympathy for the views or actions being explained. This is an important distinction because we need to be able to understand and explain terrible events and behavior in attempting to discourage it.
Justification is a normative activity
One way of explaining the theory of justification is to say that a justified belief is one that we are “within our rights” in holding. The rights in question are neither political nor moral, however, but intellectual.
In some way, each of us is responsible for what we believe. Beliefs are not typically formed completely at random, and thus we have an intellectual responsibility, or obligation, to try to believe what is true and to avoid believing what is false. An intellectually responsible act is within one’s intellectual rights in believing something; performing it, one is justified in one’s belief.
Thus, justification is a normative notion. The standard definition is that a concept is normative if it is a concept regarding or depending on the norms, or obligations and permissions (very broadly construed), involved in human conduct. It is generally accepted that the concept of justification is normative, because it is defined as a concept regarding the norms of belief.
Theories of justification
There are several different views as to what entails justification, mostly focusing on the question “How sure do we need to be that our beliefs correspond to the actual world?” Different theories of justification require different amounts and types of evidence before a belief can be considered justified. Interestingly, theories of justification generally include other aspects of epistemology, such as knowledge.
The main theories of justification include:
- Coherentism – Beliefs are justified if they cohere with other beliefs a person holds, each belief is justified if it coheres with the overall system of beliefs.
- Externalism – Outside sources of knowledge can be used to justify a belief.
- Foundationalism – Self-evident basic beliefs justify other non-basic beliefs.
- Foundherentism – A combination of foundationalism and coherentism, proposed by Susan Haack.
- Infinitism – Beliefs are justified by infinite chains of reasons.
- Internalism – The believer must be able to justify a belief through internal knowledge.
Minority viewpoints include:
- Reformed epistemology – Beliefs are warranted by proper cognitive function, proposed by Alvin Plantinga.
- Skepticism – A variety of viewpoints questioning the possibility of knowledge.
- truth skepticism – Questions the possibility of true knowledge, but not of justified knowledge
- epistemological skepticism – Questions the possibility of justified knowledge, but not true knowledge
- Evidentialism – Beliefs depend solely on the evidence for them
If a belief is justified, there is something that justifies it. The thing that justifies a belief can be called its “justifier”. If a belief is justified, then it has at least one justifier. An example of a justifier would be an item of evidence. For example, if a woman is aware of the fact that her husband returned from a business trip smelling like perfume, and that his shirt has smudged lipstick on its collar, the perfume and the lipstick can be evidence for her belief that her husband is having an affair. In that case, the justifiers are the woman’s awareness of the perfume and the lipstick, and the belief that is justified is her belief that her husband is having an affair.
Not all justifiers have to be what can properly be called “evidence”; there may be some substantially different kinds of justifiers available to us. Regardless, to be justified, a belief has to have a justifier.
But this raises an important question: what sort of thing can be a justifier?
Three things that have been suggested are:
- Beliefs only.
- Beliefs together with other conscious mental states.
- Beliefs, conscious mental states, and other facts about us and our environment (which we may or may not have access to).
At least sometimes, the justifier of a belief is another belief. When, to return to the earlier example, the woman believes that her husband is having an affair, she bases that belief on other beliefs—namely, beliefs about the lipstick and perfume. Strictly speaking, her belief isn’t based on the evidence itself—after all, what if she did not believe it? What if she thought that all of that evidence were just a hoax? What if her husband commonly wears perfume and lipstick on business trips? For that matter, what if the evidence existed, but she did not know about it? Then, of course, her belief that her husband is having an affair wouldn’t be based on that evidence, because she did not know it was there at all; or, if she thought that the evidence were a hoax, then surely her belief couldn’t be based on that evidence.
Consider a belief P. Either P is justified or P is not justified. If P is justified, then another belief Q may be justified by P. If P is not justified, then P cannot be a justifier for any other belief: neither for Q, nor for Q’s negation.
For example, suppose someone might believe that there is intelligent life on Mars, and base this belief on a further belief, that there is a feature on the surface of Mars that looks like a face, and that this face could only have been made by intelligent life. So the justifying belief is: that face-like feature on Mars could only have been made by intelligent life. And the justified belief is: there is intelligent life on Mars.
But suppose further that the justifying belief is itself unjustified. It would in no way be one’s intellectual right to suppose that this face-like feature on Mars could have only been made by intelligent life; that view would be irresponsible, intellectually speaking. Such a belief would be unjustified. It has a justifier, but the justifier is itself not justified. In fact, more recent observations have shown that the “helmeted face” does not look the same up close, nor when viewed from the side.
Commonly used justifiers
- Abductive reasoning
- Occam’s Razor
- Probability theory
- Scientific method
- Logical positivism
The major opposition against the theory of justification (also called ‘justificationism’ in this context) is nonjustificational criticism (a synthesis of skepticism and absolutism) which is most notably held by some of the proponents of critical rationalism: W. W. Bartley, David Miller and Karl Popper. (But not all proponents of critical rationalism oppose justificationism; it is supported most prominently by John W. N. Watkins.)
In justificationism, criticism consists of trying to show that a claim cannot be reduced to the authority or criteria that it appeals to. That is, it regards the justification of a claim as primary, while the claim itself is secondary. By contrast, nonjustificational criticism works towards attacking claims themselves.
Bartley also refers to a third position, which he calls critical rationalism in a more specific sense, claimed to have been Popper’s view in his Open Society. It has given up justification, but not yet adopted nonjustificational criticism. Instead of appealing to criteria and authorities, it attempts to describe and explicate them.
Fogelin claims to detect a suspicious resemblance between the Theories of Justification and Agrippa‘s five modes leading to the suspension of belief. He concludes that the modern proponents have made no significant progress in responding to the ancient modes of pyrrhonic skepticism.