Verificationism, also known as the verification principle or the verifiability criterion of meaning, is the philosophical doctrine that only statements that are empirically verifiable (i.e. verifiable through the senses) are cognitively meaningful, or else they are truths of logic (tautologies).

Verificationism thus rejects as cognitively "meaningless" statements specific to entire fields such as metaphysics, theology, ethics and aesthetics. Such statements may be meaningful in influencing emotions or behavior, but not in terms of conveying truth value, information or factual content.[1] Verificationism was a central thesis of logical positivism, a movement in analytic philosophy that emerged in the 1920s by the efforts of a group of philosophers who sought to unify philosophy and science under a common naturalistic theory of knowledge.


Although verificationist principles of a general sort—grounding scientific theory in some verifiable experience—are found retrospectively even with the American pragmatist C.S. Peirce and with the French conventionalist Pierre Duhem[2] who fostered instrumentalism,[3] the vigorous program termed verificationism was launched by the logical positivists who, emerging from Berlin Circle and Vienna Circle in the 1920s, sought epistemology whereby philosophical discourse would be, in their perception, as authoritative and meaningful as empirical science.

Logical positivists garnered the verifiability criterion of cognitive meaningfulness from young Ludwig Wittgenstein's philosophy of language posed in his 1921 book Tractatus,[4] and, led by Bertrand Russell, sought to reformulate the analytic–synthetic distinction in a way that would reduce mathematics and logic to semantical conventions. This would be pivotal to verificationism, in that logic and mathematics would otherwise be classified as synthetic a priori knowledge and defined as "meaningless" under verificationism.

Seeking grounding in such empiricism as of David Hume,[5] Auguste Comte, and Ernst Mach—along with the positivism of the latter two—they borrowed some perspectives from Immanuel Kant, and found the exemplar of science to be Albert Einstein's general theory of relativity.


Logical positivists within the Vienna Circle recognized quickly that the verifiability criterion was too stringent. Notably, all universal generalizations are empirically unverifiable, such that, under verificationism, vast domains of science and reason, such as scientific hypothesis, would be rendered meaningless.[6]

Rudolf Carnap, Otto Neurath, Hans Hahn and Philipp Frank led a faction seeking to make the verifiability criterion more inclusive, beginning a movement they referred to as the "liberalization of empiricism". Moritz Schlick and Friedrich Waismann led a "conservative wing" that maintained a strict verificationism. Whereas Schlick sought to reduce universal generalizations to frameworks of 'rules' from which verifiable statements can be derived,[7] Hahn argued that the verifiability criterion should accede to less-than-conclusive verifiability.[8] Among other ideas espoused by the liberalization movement were physicalism, over Mach's phenomenalism, coherentism over foundationalism, as well as pragmatism and fallibilism.[6][9]

In 1936, Carnap sought a switch from verification to confirmation.[6] Carnap's confirmability criterion (confirmationism) would not require conclusive verification (thus accommodating for universal generalizations) but allow for partial testability to establish "degrees of confirmation" on a probabilistic basis. Carnap never succeeded in formalizing his thesis despite employing abundant logical and mathematical tools for this purpose. In all of Carnap's formulations, a universal law's degree of confirmation is zero.[10]

That same year saw the publication of A. J. Ayer's work, Language, Truth and Logic, in which he proposed two types of verification: strong and weak. This system espoused conclusive verification, yet accommodated for probabilistic inclusion where verifiability is inconclusive. Ayer also distinguished between practical and theoretical verifiability. Under the latter, propositions that cannot be verified in practice would still be meaningful if they can be verified in principle.

Karl Popper's The Logic of Scientific Discovery proposed falsificationism as a criterion under which scientific hypothesis would be tenable. Falsificationism would allow hypotheses expressed as universal generalizations, such as "all swans are white", to be provisionally true until falsified by evidence, in contrast to verificationism under which they would be disqualified immediately as meaningless.

Though generally considered a revision of verificationism,[4][11] Popper intended falsificationism as a methodological standard specific to the sciences rather than as a theory of meaning.[4] Popper regarded scientific hypotheses to be unverifiable, as well as not "confirmable" under Carnap's thesis.[4][12] He also found non-scientific, metaphysical, ethical and aesthetic statements often rich in meaning and important in the origination of scientific theories.[4][13]


The 1951 article "Two Dogmas of Empiricism", by Willard Van Orman Quine, attacked the analytic/synthetic division and apparently rendered the verificationist program untenable. Carl Hempel, one of verificationism's greatest internal critics, had recently concluded the same as to the verifiability criterion.[14] In 1958, Norwood Hanson explained that even direct observations must be collected, sorted, and reported with guidance and constraint by theory, which sets a horizon of expectation and interpretation, how observational reports, never neutral, are laden with theory.[15]

Thomas Kuhn's landmark book of 1962, The Structure of Scientific Revolutions—which identified paradigms of science overturned by revolutionary science within fundamental physics—critically destabilized confidence in scientific foundationalism,[16] commonly if erroneously attributed to verificationism.[17] Popper, who had long claimed to have killed verificationism but recognized that some would confuse his falsificationism for more of it,[11] was knighted in 1965. In 1967, John Passmore, a leading historian of 20th-century philosophy, wrote, "Logical positivism is dead, or as dead as a philosophical movement ever becomes"—a general view among philosophers.[18] Logical positivism's fall heralded postpositivism, where Popper's view of human knowledge as hypothetical, continually growing, and open to change ascended,[11] and verificationism became mostly maligned.[2]


Although Karl Popper's falsificationism has been widely criticized by philosophers,[19] Popper has been the only philosopher of science often praised by many scientists.[12] Verificationists, in contrast, have been likened to economists of the 19th century who took circuitous, protracted measures to refuse refutation of their preconceived principles.[20] Still, logical positivists practiced Popper's principles—conjecturing and refuting—until they ran their course, catapulting Popper, initially a contentious misfit, to carry the richest philosophy out of interwar Vienna.[11] And his falsificationism, as did verificationism, poses a criterion, falsifiability, to ensure that empiricism anchors scientific theory.[2]

In a 1979 interview, A J Ayer, who had introduced logical positivism to the English-speaking world in the 1930s, was asked what he saw as its main defects, and answered that "nearly all of it was false".[18] Still, he soon admitted still holding "the same general approach".[18] The "general approach" of empiricism and reductionism—whereby mental phenomena resolve to the material or physical, and philosophical questions largely resolve to ones of language and meaning—has run through Western philosophy since the 17th century and lived beyond logical positivism's fall.[18]

In 1977, Ayer had noted, "The verification principle is seldom mentioned and when it is mentioned it is usually scorned; it continues, however, to be put to work. The attitude of many philosophers reminds me of the relationship between Pip and Magwitch in Dickens's Great Expectations. They have lived on the money, but are ashamed to acknowledge its source".[2] In the late 20th and early 21st centuries, the general concept of verification criteria—in forms that differed from those of the logical positivists—was defended by Bas van Fraassen, Michael Dummett, Crispin Wright, Christopher Peacocke, David Wiggins, Richard Rorty, and others.[2]

See also


  1. ^ Editors of Encyclopædia Britannica, "Verifiability principle", Encyclopædia Britannica, Website accessed 12 Mar 2014.
  2. ^ a b c d e C J Misak, Verificationism: Its History and Prospects (New York: Routledge, 1995), p viii.
  3. ^ Miran Epstein, ch 2 "Introduction to philosophy of science", in Clive Seale, ed, Researching Society and Culture, 3rd edn (London: Sage Publications, 2012), pp 18–19.
  4. ^ a b c d e Karl Popper, ch 4, subch "Science: Conjectures and refutations", in Andrew Bailey, ed, First Philosophy: Fundamental Problems and Readings in Philosophy, 2nd edn (Peterborough Ontario: Broadview Press, 2011), pp 338–42.
  5. ^ Despite Hume's radical empiricism, set forth near 1740, Hume was also committed to common sense, and apparently did not take his own skepticism, such as the problem of induction, as drastically as others later did [Antony G Flew, A Dictionary of Philosophy, rev 2nd edn (New York: St Martin's Press, 1984), "Hume", p 156].
  6. ^ a b c Sahotra Sarkar and Jessica Pfeifer, eds, The Philosophy of Science: An Encyclopedia, Volume 1: A–M (New York: Routledge, 2006), "Rudolf Carnap", p 83.
  7. ^ Moritz Schlick, 1931, "Die Kausalität in der gegenwärtigen Physik", Die Naturwissen-schaften, 19: 145–162; transl. "Causality in Contemporary Physics" in Schlick 1979b, pp. 176–209
  8. ^ Hahn, Hans, 1933, Logik, Mathematik und Naturerkennen, Wien: Gerold, transl. "Logic, Mathematics, and Knowledge of Nature", in B. McGuiness 1987, pp. 24–45.
  9. ^ Antony G Flew, A Dictionary of Philosophy, rev 2nd edn (New York: St Martin's Press, 1984), "Neurath", p 245.
  10. ^ Mauro Murzi "Rudolf Carnap (1891–1970)", Internet Encyclopedia of Philosophy, 12 Apr 2001.
  11. ^ a b c d Malachi Haim Hacohen, Karl Popper: The Formative Years, 1902–1945: Politics and Philosophy in Interwar Vienna (Cambridge: Cambridge University Press, 2000), pp 212–13.
  12. ^ a b Peter Godfrey-Smith, Theory and Reality: An Introduction to the Philosophy of Science (Chicago: University of Chicago Press, 2005), p 57–59.
  13. ^ Falsificationism is simply Popper's scientific epistemology, whereas critical rationalism is Popper's general epistemology.
  14. ^ James Fetzer, "Carl Hempel", in Edward N Zalta, ed, The Stanford Encyclopedia of Philosophy (Spring 2013): "However surprising it may initially seem, contemporary developments in the philosophy of science can only be properly appreciated in relation to the historical background of logical positivism. Hempel himself attained a certain degree of prominence as a critic of this movement. Language, Truth and Logic (1936; 2nd edition, 1946), authored by A J Ayer, offers a lucid exposition of the movement, which was—with certain variations—based upon the analytic/synthetic distinction, the observational/theoretical distinction, and the verifiability criterion of meaningfulness.

    Hempel (1950, 1951), meanwhile, demonstrated that the verifiability criterion could not be sustained. Since it restricts empirical knowledge to observation sentences and their deductive consequences, scientific theories are reduced to logical constructions from observables. In a series of studies about cognitive significance and empirical testability, he demonstrated that the verifiability criterion implies that existential generalizations are meaningful, but that universal generalizations are not, even though they include general laws, the principal objects of scientific discovery. Hypotheses about relative frequencies in finite sequences are meaningful, but hypotheses concerning limits in infinite sequences are not. The verifiability criterion thus imposed a standard that was too strong to accommodate the characteristic claims of science and was not justifiable".
  15. ^ Bruce Caldwell, Beyond Positivism: Economic Methodology in the 20th Century, rev edn (London: Routledge, 1994), p 47–48.
  16. ^ Samir Okasha, Philosophy of Science: A Very Short Introduction (New York: Oxford University Press, 2002) ch 5.
  17. ^ "But for a brief lapse around 1929/30, then, the post-Aufbau Carnap fully represents the position of Vienna Circle anti-foundationalism. In this he joined Neurath whose long-standing anti-foundationalism is evident from his famous simile likening scientists to sailors who have to repair their boat without ever being able to pull into dry dock (1932b). Their positions contrasted at least prima facie with that of Schlick (1934) who explicitly defended the idea of foundations in the Circle's protocol-sentence debate. Even Schlick conceded, however, that all scientific statements were fallible ones, so his position on foundationalism was by no means the traditional one. The point of his 'foundations' remained less than wholly clear and different interpretation of it have been put forward. ... While all in the Circle thus recognized as futile the attempt to restore certainty to scientific knowledge claims, not all members embraced positions that rejected foundationalism tout court. Clearly, however, attributing foundationalist ambitions to the Circle as a whole constitutes a total misunderstanding of its internal dynamics and historical development, if it does not bespeak wilfull ignorance. At most, a foundationalist faction around Schlick can be distinguished from the so-called left wing whose members pioneered anti-foundationalism with regard to both the empirical and formal sciences" Thomas Uebel, "Vienna Circle", sec "3.3 Reductionism and foundationalism: Two criticisms partly rebutted", in Edward N Zalta, ed, The Stanford Encyclopedia of Philosophy (Summer 2012 edn).
  18. ^ a b c d Oswald Hanfling, ch 5 "Logical positivism", in Stuart G Shanker, Philosophy of Science, Logic and Mathematics in the Twentieth Century (London: Routledge, 1996), pp 193–94.
  19. ^ Shea, Brendan. "Karl Popper: Philosophy of Science". Internet Encyclopedia of Philosophy. Retrieved May 12, 2019.
  20. ^ Mark Blaug The Methodology of Economics: Or, How Economists Explain, 2nd edn (Cambridge UK: Cambridge University Press, 1992), ch 3 "The verificationists, a largely nineteenth-century story", p 51.
Agnostic existentialism

Agnostic existentialism is a type of existentialism which makes no claim to know whether there is a "greater picture"; rather, it simply asserts that the greatest truth is that which the individual chooses to act upon. It feels that to know the greater picture, whether there is one or not, is impossible, or impossible so far, or of little value. Like the Christian existentialist, the agnostic existentialist believes existence is subjective.

Argument from love

The Argument from love is an argument for the existence of God. The best-known defender of the argument is Roger Scruton.

Argument from miracles

The argument from miracles is an argument for the existence of God that relies on the belief that events witnessed and described as miracles – i.e. as events not explicable by natural or scientific laws – indicate the intervention of the supernatural.

One example of this argument is the Christological argument: the claim that historical evidence proves that Jesus Christ rose from the dead and that this can only be explained if God exists. Another is the claim that many of the Qur'an's prophecies have been fulfilled and that this too can only be explained if God (Allah) exists.

Defenders of the argument include C. S. Lewis, G. K. Chesterton and William of Ockham.

Berlin Circle

The Berlin Circle (German: die Berliner Gruppe) was a group that maintained logical empiricist views about philosophy.

Constructive empiricism

In philosophy, constructive empiricism (also empiricist structuralism) is a form of empiricism.

Demarcation problem

The demarcation problem in the philosophy of science and epistemology is about how to distinguish between science and non-science, including between science, pseudoscience, and other products of human activity, like art and literature, and beliefs. The debate continues after over two millennia of dialogue among philosophers of science and scientists in various fields, and despite a broad agreement on the basics of the scientific method.

Epistemic theories of truth

In philosophy, epistemic theories of truth are attempts to analyze the notion of truth in terms of epistemic notions such as knowledge, belief, acceptance, verification, justification, and perspective.

A variety of such conceptions can be classified into verificationist theories, perspectivalist or relativist theories, and pragmatic theories.

Verificationism is based on verifying propositions. The distinctive claim of verificationism is that the result of such verifications is, by definition, truth. That is, truth is reducible to this process of verification.

According to perspectivalism and relativism, a proposition is only true relative to a particular perspective. Roughly, a proposition is true relative to a perspective if and only if it is accepted, endorsed, or legitimated by that perspective.

Many authors writing on the topic of the notion of truth advocate or endorse combinations of the above positions. Each of these epistemic conceptions of truth can be subjected to various criticisms. Some criticisms apply across the board, while others are more specific.

Epistemological idealism

Epistemological idealism is a subjectivist position in epistemology that holds that what one knows about an object exists only in one's mind. It is opposed to epistemological realism.

Eschatological verification

Eschatological verification describes a process whereby a proposition can be verified after death. A proposition such as "there is an afterlife" is verifiable if true but not falsifiable if false (if it's false, the individual will not know it's false, because they have no state of being). The term is most commonly used in relation to God and the afterlife, although there may be other propositions - such as moral propositions - which may also be verified after death.

John Hick has expressed the premise as an allegory of a quest to a Celestial City. In this parable, a theist and an atheist are both walking down the same road. The theist believes there is a destination, the atheist believes there is not. If they reach the destination, the theist will have been proven right; however, if there is no destination on an endless road, this can never be verified. This is an attempt to explain how a theist expects some form of life or existence after death and an atheist does not. They both have separate belief systems and live life accordingly, but logically one is right and the other is not. If the theist is right, he will be proven so when he arrives in the afterlife. However, if the atheist is right, they will simply both be dead and nothing will be verified.

This acts as a response to Verificationism. Under Hick's analogy claims about the afterlife are verifiable in principle because the truth becomes clear after death. To some extent it is therefore wrong to claim that religious language cannot be verified because it can (when you're dead).


A statement, hypothesis, or theory has falsifiability (or is falsifiable) if it is contradicted by a basic statement, which, in an eventual successful or failed falsification, must respectively correspond to a true or hypothetical observation. For example, the claim "all swans are white and have always been white" is falsifiable since it is contradicted by this basic statement: "In 1697, during the Dutch explorer Willem de Vlamingh expedition, there were black swans on the shore of the Swan River in Australia", which in this case is a true observation. The concept is also known by the terms refutable and refutability.

The concept was introduced by the philosopher of science Karl Popper. He saw falsifiability as the logical part and the cornerstone of his scientific epistemology, which sets the limits of scientific inquiry. He proposed that statements and theories that are not falsifiable are unscientific. Declaring an unfalsifiable theory to be scientific would then be pseudoscience.

God and Other Minds

God and Other Minds is a 1967 book by the American philosopher of religion Alvin Plantinga which re-kindled philosophical debate on the existence of God in Anglo-American philosophical circles by arguing that belief in God was like belief in other minds: although neither could be demonstrated conclusively against a determined sceptic both were fundamentally rational. Though Plantinga later modified some of his views, particularly on the soundness of the ontological argument and on the nature of epistemic rationality, he still stands by the basic theses of the book.

Holy Spirit

Holy Spirit, is a term found in English translations of the Bible that is understood differently among the Abrahamic religions. The term is also used to describe aspects of other religions and belief structures.

Index of analytic philosophy articles

This is a list of articles in analytic philosophy.

A. C. Grayling

A.P. Martinich

Abstract particulars


Alfred Jules Ayer


Analytic-synthetic distinction

Analytic philosophy

Analytic reasoning

Arda Denkel

Arthur Danto

Australian Realism

Avrum Stroll


Berlin Circle

Bernard Williams

Bertrand Russell


Breaking the Spell: Religion as a Natural Phenomenon

C. D. Broad

Cahiers pour l'Analyse

Carl Gustav Hempel

Ramsey sentence

Charles Sanders Peirce

Chinese room

Cognitive synonymy

Contemporary Pragmatism

Contrast theory of meaning

Cooperative principle

Cora Diamond

Daniel Dennett

Darwin's Dangerous Idea

David Braine (philosopher)

David Kellogg Lewis


Descriptivist theory of names


Direct reference theory

Doctrine of internal relations

Donald Davidson (philosopher)

Doxastic logic

Elbow Room (book)

Elliott Sober


Ernst Mach

Eternal statement

F. C. S. Schiller

Family resemblance

Felicity conditions

Form of life (philosophy)

Frank P. Ramsey

Freedom Evolves

Friedrich Waismann

G. E. M. Anscombe

George Edward Moore

Gilbert Ryle

Gottlob Frege

Gricean maxims

Gustav Bergmann

Hans Hahn

Hans Reichenbach

Hans Sluga

Harvey Brown (philosopher)

Herbert Feigl


Hypothetico-deductive model

Indeterminacy of translation

Introduction to Mathematical Philosophy

Isaiah Berlin

J. L. Austin

Jeff Malpas

Jerry Fodor

John Hick

John Rawls

John Searle

John Wisdom

Jules Vuillemin

Karl Menger

Kit Fine

Kurt Grelling

Kwasi Wiredu

Language, Truth, and Logic

Logical atomism

Logical form

Logical positivism

Lorenzo Peña

Ludwig Wittgenstein

Mark Addis

Mark Sacks

Max Black

Mental representation

Metaphor in philosophy

Michael Dummett

Michael Tye (philosopher)

Modal realism

Moritz Schlick

Naming and Necessity

Nelson Goodman



Norman Malcolm

Oets Kolk Bouwsma

Olaf Helmer

Olga Hahn-Neurath

On Certainty

On Denoting

Ordinary language philosophy

Original proof of Gödel's completeness theorem

Ostensive definition

Otto Neurath

P. F. Strawson

Paradox of analysis

Paul Churchland

Paul Grice

Per Martin-Löf

Peter Hacker

Peter Simons

Philipp Frank

Philippa Foot

Philosophical analysis

Philosophical Investigations

Philosophy of engineering

Philosophy of technology

Pieranna Garavaso

Postanalytic philosophy


Principia Ethica

Principia Mathematica

Private language argument

Process philosophy

Radical translation

Richard von Mises

Robert Audi

Rose Rand

Round square copula

Rudolf Carnap

Rupert Read

Ryle's regress

Speech act

Stephen Laurence

Susan Stebbing

The Bounds of Sense

The Logic of Scientific Discovery

The Mind's I

Theodore Drange

Þorsteinn Gylfason

Tore Nordenstam

Tractatus Logico-Philosophicus

Two Dogmas of Empiricism

UCLA Department of Philosophy

Use–mention distinction

Verification theory


Victor Kraft

Vienna Circle

Wilfrid Sellars

Willard Van Orman Quine

William James Lectures

William L. Rowe

William W. Tait

Wolfgang Stegmüller

Word and Object

Zeno Vendler

List of philosophies

Philosophical schools of thought and philosophical movements.

Logical positivism

Logical positivism and logical empiricism, which together formed neopositivism, was a movement in Western philosophy whose central thesis was verificationism, a theory of knowledge which asserted that only statements verifiable through empirical observation are meaningful. The movement flourished in the 1920s and 1930s in several European centers.

Efforts to convert philosophy to this new "scientific philosophy", shared with empirical sciences' best examples, such as Albert Einstein's general theory of relativity, sought to prevent confusion rooted in unclear language and unverifiable claims.The Berlin Circle and Vienna Circle—groups of philosophers, scientists, and mathematicians in Berlin and Vienna—propounded logical positivism, starting in the late 1920s.

Natural-law argument

Natural-law argument for the existence of God was especially popular in the eighteenth century as a result of the influence of Sir Isaac Newton. As Bertrand Russell pointed out much later, many of the things we consider to be laws of nature, in fact, are human conventions. Indeed, Albert Einstein has shown that Newton's law of universal gravitation was such a convention, and though elegant and useful, one that did not describe the universe precisely. Most true laws are rather trivial, such as mathematical laws, laws of probability, and so forth, and much less impressive than those that were envisioned by Newton and his followers. Russell wrote:

"If you say, as more orthodox theologians do, that in all the laws which God issues he had a reason for giving those laws rather than others -- the reason, of course, being to create the best universe, although you would never think it to look at it -- if there was a reason for the laws which God gave, then God himself was subject to law, and therefore you do not get any advantage by introducing God as an intermediary. You really have a law outside and anterior to the divine edicts, and God does not serve your purpose, because he is not the ultimate law-giver. In short, this whole argument from natural law no longer has anything like the strength that it used to have."The argument of natural laws as a basis for God was changed by Christian figures such as Thomas Aquinas, in order to fit biblical scripture and establish a Judeo-Christian teleological law.

Open texture

Open texture is a term in the philosophy of Friedrich Waismann, first introduced in his paper Verifiability to refer to the universal possibility of vagueness in empirical statements. The concept has become important in criticism of verificationism and has also found use in legal philosophy.


In philosophy and models of scientific inquiry, postpositivism (also called postempiricism) is a metatheoretical stance that critiques and amends positivism. While positivists emphasize independence between the researcher and the researched person (or object), postpositivists argue that theories, background, knowledge and values of the researcher can influence what is observed. Postpositivists pursue objectivity by recognizing the possible effects of biases. While positivists emphasize quantitative methods, postpositivists consider both quantitative and qualitative methods to be valid approaches.

Russian Machism

Russian Machism is a political/philosophical viewpoint which emerged in Imperial Russia in the beginning of the twentieth century before the Russian Revolution. They upheld the scientific and philosophical insights of Ernst Mach to be of great interest. Many of the Russian Machists were Marxists, and indeed viewed Machism as an essential ingredient of a materialist outlook on the world.

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