Verification principle
   HOME

TheInfoList



OR:

Verificationism, also known as the verification principle or the verifiability criterion of meaning, is the philosophical doctrine which maintains that only statements that are empirically verifiable (i.e. verifiable through the
sense A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of Stimulus (physiology), stimuli. (For example, in the human body, the brain which is part of the cen ...
s) are cognitively meaningful, or else they are truths of logic ( tautologies). Verificationism thus rejects statements related to
metaphysics Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...
, as well as fields such as
theology Theology is the systematic study of the nature of the divine and, more broadly, of religious belief. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of analyzing the ...
,
ethics Ethics or moral philosophy is a branch of philosophy that "involves systematizing, defending, and recommending concepts of right and wrong behavior".''Internet Encyclopedia of Philosophy'' The field of ethics, along with aesthetics, concerns m ...
and
aesthetics Aesthetics, or esthetics, is a branch of philosophy that deals with the nature of beauty and taste, as well as the philosophy of art (its own area of philosophy that comes out of aesthetics). It examines aesthetic values, often expressed thr ...
, as "cognitively meaningless". Such statements may be meaningful in influencing emotions or behaviour, but not in terms of conveying
truth value In logic and mathematics, a truth value, sometimes called a logical value, is a value indicating the relation of a proposition to truth, which in classical logic has only two possible values (''true'' or '' false''). Computing In some progr ...
, information or factual content. Verificationism was a central thesis of
logical positivism Logical positivism, later called logical empiricism, and both of which together are also known as neopositivism, is a movement in Western philosophy whose central thesis was the verification principle (also known as the verifiability criterion o ...
, a movement in
analytic philosophy Analytic philosophy is a branch and tradition of philosophy using analysis, popular in the Western world and particularly the Anglosphere, which began around the turn of the 20th century in the contemporary era in the United Kingdom, United Sta ...
that emerged in the 1920s by philosophers who sought to unify philosophy and science under a common naturalistic theory of knowledge.


Origins

Although verificationist principles of a general sort—grounding scientific theory in some verifiable
experience Experience refers to conscious events in general, more specifically to perceptions, or to the practical knowledge and familiarity that is produced by these conscious processes. Understood as a conscious event in the widest sense, experience involv ...
—are found retrospectively even with the American pragmatist
C.S. Peirce Charles Sanders Peirce ( ; September 10, 1839 – April 19, 1914) was an American philosopher, logician, mathematician and scientist who is sometimes known as "the father of pragmatism". Educated as a chemist and employed as a scientist for t ...
and with the French
conventionalist Conventionalism is the philosophical attitude that fundamental principles of a certain kind are grounded on (explicit or implicit) agreements in society, rather than on external reality. Unspoken rules play a key role in the philosophy's structur ...
Pierre Duhem Pierre Maurice Marie Duhem (; 9 June 1861 – 14 September 1916) was a French theoretical physicist who worked on thermodynamics, hydrodynamics, and the theory of elasticity. Duhem was also a historian of science, noted for his work on the Euro ...
, who fostered instrumentalism,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
the vigorous program of ''verificationism'' was launched by the
logical positivists Logical positivism, later called logical empiricism, and both of which together are also known as neopositivism, is a movement in Western philosophy whose central thesis was the verification principle (also known as the verifiability criterion o ...
who, emerging from the Berlin Circle and the Vienna Circle in the 1920s, sought an
epistemology Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics. Episte ...
whereby philosophical discourse would be, in their perception, as authoritative and meaningful as an empirical science. Logical positivists garnered the verifiability criterion of cognitive meaningfulness from
Ludwig Wittgenstein Ludwig Josef Johann Wittgenstein ( ; ; 26 April 1889 – 29 April 1951) was an Austrian-British philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language. He is considere ...
's
philosophy of language In analytic philosophy, philosophy of language investigates the nature of language and the relations between language, language users, and the world. Investigations may include inquiry into the nature of meaning, intentionality, reference, ...
posed in his 1921 book '' Tractatus'', and, led by
Bertrand Russell Bertrand Arthur William Russell, 3rd Earl Russell, (18 May 1872 – 2 February 1970) was a British mathematician, philosopher, logician, and public intellectual. He had a considerable influence on mathematics, logic, set theory, linguistics, ...
, 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 In philosophy, empiricism is an epistemological theory that holds that knowledge or justification comes only or primarily from sensory experience. It is one of several views within epistemology, along with rationalism and skepticism. Empir ...
as of
David Hume David Hume (; born David Home; 7 May 1711 NS (26 April 1711 OS) – 25 August 1776) Cranston, Maurice, and Thomas Edmund Jessop. 2020 999br>David Hume" ''Encyclopædia Britannica''. Retrieved 18 May 2020. was a Scottish Enlightenment philo ...
,
Auguste Comte Isidore Marie Auguste François Xavier Comte (; 19 January 1798 – 5 September 1857) was a French philosopher and writer who formulated the doctrine of positivism. He is often regarded as the first philosopher of science in the modern sense ...
, and
Ernst Mach Ernst Waldfried Josef Wenzel Mach ( , ; 18 February 1838 – 19 February 1916) was a Moravian-born Austrian physicist and philosopher, who contributed to the physics of shock waves. The ratio of one's speed to that of sound is named the Mach ...
—along with the
positivism Positivism is an empiricist philosophical theory that holds that all genuine knowledge is either true by definition or positive—meaning ''a posteriori'' facts derived by reason and logic from sensory experience.John J. Macionis, Linda M. G ...
of the latter two—they borrowed some perspectives from
Immanuel Kant Immanuel Kant (, , ; 22 April 1724 – 12 February 1804) was a German philosopher and one of the central Enlightenment thinkers. Born in Königsberg, Kant's comprehensive and systematic works in epistemology, metaphysics, ethics, and ...
, and found the exemplar of science to be
Albert Einstein Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
's general theory of relativity.


Revisions

Logical positivists within the Vienna Circle recognized quickly that the verifiability criterion was too stringent. Notably, all
universal generalization In predicate logic, generalization (also universal generalization or universal introduction,Moore and Parker GEN) is a valid inference rule. It states that if \vdash \!P(x) has been derived, then \vdash \!\forall x \, P(x) can be derived. Gener ...
s are empirically unverifiable, such that, under verificationism, vast domains of science and reason, such as scientific
hypothesis A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous obse ...
, would be rendered meaningless.Sahotra Sarkar and Jessica Pfeifer, eds, ''The Philosophy of Science: An Encyclopedia'', Volume 1: A–M (New York: Routledge, 2006), "Rudolf Carnap"
p. 83
Rudolf Carnap Rudolf Carnap (; ; 18 May 1891 – 14 September 1970) was a German-language philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism. He ...
, Otto Neurath, Hans Hahn and
Philipp Frank Philipp Frank (March 20, 1884 – July 21, 1966) was a physicist, mathematician and philosopher of the early-to-mid 20th century. He was a logical positivist, and a member of the Vienna Circle. He was influenced by Mach and was one of the Machist ...
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 Friedrich Waismann (; 21 March 18964 November 1959) was an Austrian mathematician, physicist, and philosopher. He is best known for being a member of the Vienna Circle and one of the key theorists in logical positivism. Biography Born to a Jewis ...
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,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 Hahn argued that the verifiability criterion should accede to less-than-conclusive verifiability.Hahn, Hans, 1933, Logik, Mathematik und Naturerkennen, Wien: Gerold, transl. "Logic, Mathematics, and Knowledge of Nature", in B. McGuiness 1987, pp. 24–45. Among other ideas espoused by the liberalization movement were
physicalism In philosophy, physicalism is the metaphysical thesis that "everything is physical", that there is "nothing over and above" the physical, or that everything supervenes on the physical. Physicalism is a form of ontological monism—a "one substanc ...
, over
Mach Mach may refer to Mach number, the speed of sound in local conditions. It may also refer to: Computing * Mach (kernel), an operating systems kernel technology * ATI Mach, a 2D GPU chip by ATI * GNU Mach, the microkernel upon which GNU Hurd is bas ...
's
phenomenalism In metaphysics, phenomenalism is the view that physical objects cannot justifiably be said to exist in themselves, but only as perceptual phenomena or sensory stimuli (e.g. redness, hardness, softness, sweetness, etc.) situated in time and in sp ...
, coherentism over
foundationalism Foundationalism concerns philosophical theories of knowledge resting upon non-inferential justified belief, or some secure foundation of certainty such as a conclusion inferred from a basis of sound premises.Simon Blackburn, ''The Oxford Dictio ...
, as well as pragmatism and fallibilism.Antony G Flew, ''A Dictionary of Philosophy'', rev 2nd edn (New York: St Martin's Press, 1984)
"Neurath"
p. 245.
In 1936, Carnap sought a switch from verification to ''confirmation''. 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.Mauro Murz
"Rudolf Carnap (1891–1970)"
''Internet Encyclopedia of Philosophy'', 12 Apr 2001.
That same year saw the publication of
A. J. Ayer Sir Alfred Jules "Freddie" Ayer (; 29 October 1910 – 27 June 1989), usually cited as A. J. Ayer, was an English philosopher known for his promotion of logical positivism, particularly in his books '' Language, Truth, and Logic'' (1936) ...
'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 Sir Karl Raimund Popper (28 July 1902 – 17 September 1994) was an Austrian-British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the cl ...
's '' The Logic of Scientific Discovery'' proposed falsifiability as a criterion by which a hypothesis would be scientific. Falsifiability would allow hypotheses expressed as universal generalizations, such as "all swans are white", to be scientific even though they are unverifiable, in contrast to verificationism under which they would be disqualified immediately as meaningless. Though generally considered a revision of verificationism, Popper intended falsifiability as a standard specific to the sciences rather than as a theory of meaning.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
Popper regarded scientific hypotheses to be unverifiable, as well as not "confirmable" under
Rudolf Carnap Rudolf Carnap (; ; 18 May 1891 – 14 September 1970) was a German-language philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism. He ...
's thesis.Peter Godfrey-Smith, ''Theory and Reality: An Introduction to the Philosophy of Science'' (Chicago: University of Chicago Press, 2005)
pp. 57–59
He also found non-scientific, metaphysical, ethical and aesthetic statements often rich in meaning and important in the origination of scientific theories.


Decline

The 1951 article "
Two Dogmas of Empiricism "Two Dogmas of Empiricism" is a paper by analytic philosopher Willard Van Orman Quine published in 1951. According to University of Sydney professor of philosophy Peter Godfrey-Smith, this "paper ssometimes regarded as the most important in all ...
", by
Willard Van Orman Quine Willard Van Orman Quine (; known to his friends as "Van"; June 25, 1908 – December 25, 2000) was an American philosopher and logician in the analytic tradition, recognized as "one of the most influential philosophers of the twentieth century". ...
, attacked the analytic/synthetic division and apparently rendered the verificationist program untenable.
Carl Hempel Carl Gustav "Peter" Hempel (January 8, 1905 – November 9, 1997) was a German writer, philosopher, logician, and epistemologist. He was a major figure in logical empiricism, a 20th-century movement in the philosophy of science. He is espec ...
, one of verificationism's greatest internal critics, had recently concluded the same as to the verifiability criterion.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 Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultim ...
can only be properly appreciated in relation to the historical background of
logical positivism Logical positivism, later called logical empiricism, and both of which together are also known as neopositivism, is a movement in Western philosophy whose central thesis was the verification principle (also known as the verifiability criterion o ...
.
Hempel Hempel is a name of German, Dutch and Swedish origin and the surname of a Swedish noble family. The following people have the surname: *Adolph Hempel (1870–1949), Brazilian entomologist *Amy Hempel (born 1951), American writer and professor *An ...
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 Sir Alfred Jules "Freddie" Ayer (; 29 October 1910 – 27 June 1989), usually cited as A. J. Ayer, was an English philosopher known for his promotion of logical positivism, particularly in his books '' Language, Truth, and Logic'' (1936) ...
, 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".
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.
Thomas Kuhn Thomas Samuel Kuhn (; July 18, 1922 – June 17, 1996) was an American philosopher of science whose 1962 book ''The Structure of Scientific Revolutions'' was influential in both academic and popular circles, introducing the term '' paradigm ...
's landmark book of 1962, '' The Structure of Scientific Revolutions''—which identified '' paradigms of science'' overturned by
revolutionary science A paradigm shift, a concept brought into the common lexicon by the American physicist and philosopher Thomas Kuhn, is a fundamental change in the basic concepts and experimental practices of a scientific discipline. Even though Kuhn restricted t ...
within
fundamental physics In physics, the fundamental interactions, also known as fundamental forces, are the interactions that do not appear to be reducible to more basic interactions. There are four fundamental interactions known to exist: the gravitational and electrom ...
—critically destabilized confidence in scientific
foundationalism Foundationalism concerns philosophical theories of knowledge resting upon non-inferential justified belief, or some secure foundation of certainty such as a conclusion inferred from a basis of sound premises.Simon Blackburn, ''The Oxford Dictio ...
, a theory commonly, if erroneously, attributed to verificationism. Popper had long claimed to have killed verificationism but recognized that some would confuse his falsificationism for more of it.Malachi Haim Hacohen, ''Karl Popper: The Formative Years, 1902–1945: Politics and Philosophy in Interwar Vienna'' (Cambridge:
Cambridge University Press Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing hou ...
, 2000)
pp. 212–13
In 1967,
John Passmore John Passmore AC (9 September 1914 – 25 July 2004) was an Australian philosopher. Life John Passmore was born on 9 September 1914 in Manly, Sydney, where he grew up. He was educated at Sydney Boys High School.Sydney High School Old Boys ...
, a leading historian of 20th-century philosophy, wrote, "Logical positivism is dead, or as dead as a philosophical movement ever becomes".Oswald Hanfling, ch 5 "Logical positivism", in Stuart G Shanker, ''Philosophy of Science, Logic and Mathematics in the Twentieth Century'' (London:
Routledge Routledge () is a British multinational publisher. It was founded in 1836 by George Routledge, and specialises in providing academic books, journals and online resources in the fields of the humanities, behavioural science, education, law, and ...
, 1996)
pp. 193–94
Logical positivism's fall heralded postpositivism, where Popper's view of human knowledge as hypothetical, continually growing, and open to change ascended, and verificationism became mostly maligned.


Legacy

Although
Karl Popper Sir Karl Raimund Popper (28 July 1902 – 17 September 1994) was an Austrian-British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the cl ...
's
critical rationalism Critical rationalism is an epistemological philosophy advanced by Karl Popper on the basis that, if a statement cannot be logically deduced (from what is known), it might nevertheless be possible to logically falsify it. Following Hume, Popper r ...
has been widely criticized by philosophers, Popper is often praised by many scientists.
Logical positivist Logical positivism, later called logical empiricism, and both of which together are also known as neopositivism, is a movement in Western philosophy whose central thesis was the verification principle (also known as the verifiability criterion o ...
s, in contrast, have been likened to economists of the 19th century who took circuitous, protracted measures to refuse refutation of their preconceived principles.Mark Blaug ''The Methodology of Economics: Or, How Economists Explain'', 2nd edn (Cambridge UK:
Cambridge University Press Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing hou ...
, 1992), ch 3 "The verificationists, a largely nineteenth-century story"
p. 51
Malachi Haim Hacohen, in his biography of Popper, said that 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 In the history of the 20th century, the interwar period lasted from 11 November 1918 to 1 September 1939 (20 years, 9 months, 21 days), the end of the First World War to the beginning of the Second World War. The interwar period was relativel ...
Vienna. And Popper's critical rationalism posed its own criterion, '' falsifiability'', to ensure that empiricism anchors scientific theory. In a 1979 TV interview, A. J. Ayer, who had introduced logical positivism to the
English-speaking world Speakers of English are also known as Anglophones, and the countries where English is natively spoken by the majority of the population are termed the '' Anglosphere''. Over two billion people speak English , making English the largest languag ...
in the 1930s, was asked what he saw as its main defects, and answered that "nearly all of it was false". However, he soon said that he still held "the same general approach". The "general approach" of empiricism and
reductionism Reductionism is any of several related philosophical ideas regarding the associations between phenomena which can be described in terms of other simpler or more fundamental phenomena. It is also described as an intellectual and philosophical pos ...
—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. 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 ''Great Expectations'' is the thirteenth novel by Charles Dickens and his penultimate completed novel. It depicts the education of an orphan nicknamed Pip (Great Expectations), Pip (the book is a ''bildungsroman''; a coming-of-age story). It ...
''. They have lived on the money, but are ashamed to acknowledge its source". 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 Sir Michael Anthony Eardley Dummett (27 June 1925 – 27 December 2011) was an English academic described as "among the most significant British philosophers of the last century and a leading campaigner for racial tolerance and equality." He wa ...
,
Crispin Wright Crispin James Garth Wright (; born 21 December 1942) is a British philosopher, who has written on neo-Fregean (neo-logicist) philosophy of mathematics, Wittgenstein's later philosophy, and on issues related to truth, realism, cognitivism, skep ...
, Christopher Peacocke,
David Wiggins David Wiggins (born 1933) is an English moral philosopher, metaphysician, and philosophical logician working especially on identity and issues in meta-ethics. Biography David Wiggins was born on 8 March 1933 in London, the son of Norman and D ...
,
Richard Rorty Richard McKay Rorty (October 4, 1931 – June 8, 2007) was an American philosopher. Educated at the University of Chicago and Yale University, he had strong interests and training in both the history of philosophy and in contemporary analytic phi ...
, and others.C. J. Misak, ''Verificationism: Its History and Prospects'' (New York:
Routledge Routledge () is a British multinational publisher. It was founded in 1836 by George Routledge, and specialises in providing academic books, journals and online resources in the fields of the humanities, behavioural science, education, law, and ...
, 1995)
p. viii


See also

*
Epistemic theories of truth In philosophy and epistemology, 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 conc ...
* Newton's flaming laser sword * Semantic anti-realism (epistemology)


Notes

{{Positivism Analytic philosophy Empiricism Logical positivism Metatheory of science Epistemological theories Meaning (philosophy of language) Meaning in religious language