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Karl Popper

 

 

 

 

 

Karl Popper


 
 
Sir Karl Raimund Popper was an AustriaAustria

Austria is a landlocked country in central Europe....
n and BritishUnited Kingdom

The United Kingdom of Great Britain and Northern Ireland is a country and sovereign state that lies off the northwest coast...
 philosopher and a professor at the London School of EconomicsLondon School of Economics

The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
. He is counted among the most influential philosophers of sciencePhilosophy of science

Philosophy of science is the branch of philosophy that studies the philosophical assumptions, foundations, and implications ...
 of the 20th century, and also wrote extensively on social and political philosophy. Popper is known for repudiating the classical observationalist/inductivistInductivism

In the philosophy of science inductivism exists both in a classical naive version, which has been highly influential, and in vario...
 account of scientific methodScientific method

Scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting...
 by advancing empirical falsificationFalsifiability

In science and the philosophy of science, falsifiability, contingency, and defeasibility are roughly...
 instead; for his opposition to the classical justificationist account of knowledge which he replaced with critical rationalismCritical rationalism

Critical rationalism is an epistemological philosophy advanced by Karl Raimund Popper, which is a logical generalization of ...
, "the first non justificational philosophy of criticism in the history of philosophy" and for his vigorous defense of liberal democracyLiberal democracy

Liberal democracy is a form of government....
 and the principles of social criticismSocial criticism

Social criticism analyzes social structures which are seen as flawed and aims at practical solutions by specific measures, r...
 which he took to make the flourishing of the "open societyOpen society

An open society is a concept originally developed by philosopher Henri Bergson....
" possible.
LifeKarl Popper was born in ViennaVienna

Vienna is the capital of Austria, and also one of the nine States of Austria....
 (then in Austria-HungaryAustria-Hungary

Austria-Hungary, also known as the Austro-Hungarian Empire, Dual Monarchy or k.u.k....
) in 1902 to middle-class parents of JewJew

Jews are followers of Judaism or, more generally, members of the Jewish people , an ethno-religious group descended from th...
ish origins, both of whom had converted to ChristianityFacts About Christianity

Christianity is a monotheistic religion centered on Jesus of Nazareth, and on his life and teachings as presented in the New...
.






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Timeline

1994   Died






Quotations


All things living are in search of a better world.

In Search of a Better World

If we choose freedom, then we must be prepared to perish along with it.

"On Freedom" in All Life is Problem Solving (1999)

No matter how many instances of white swans we may have observed, this does not justify the conclusion that all swans are white.

The Logic of Scientific Discovery (1959)

Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve.

Objective Knowledge: An Evolutionary Approach (1972)





Encyclopedia


Sir Karl Raimund Popper was an AustriaAustria

Austria is a landlocked country in central Europe....
n and BritishUnited Kingdom

The United Kingdom of Great Britain and Northern Ireland is a country and sovereign state that lies off the northwest coast...
 philosopher and a professor at the London School of EconomicsLondon School of Economics

The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
. He is counted among the most influential philosophers of sciencePhilosophy of science

Philosophy of science is the branch of philosophy that studies the philosophical assumptions, foundations, and implications ...
 of the 20th century, and also wrote extensively on social and political philosophy. Popper is known for repudiating the classical observationalist/inductivistInductivism

In the philosophy of science inductivism exists both in a classical naive version, which has been highly influential, and in vario...
 account of scientific methodScientific method

Scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting...
 by advancing empirical falsificationFalsifiability

In science and the philosophy of science, falsifiability, contingency, and defeasibility are roughly...
 instead; for his opposition to the classical justificationist account of knowledge which he replaced with critical rationalismCritical rationalism

Critical rationalism is an epistemological philosophy advanced by Karl Raimund Popper, which is a logical generalization of ...
, "the first non justificational philosophy of criticism in the history of philosophy" and for his vigorous defense of liberal democracyLiberal democracy

Liberal democracy is a form of government....
 and the principles of social criticismSocial criticism

Social criticism analyzes social structures which are seen as flawed and aims at practical solutions by specific measures, r...
 which he took to make the flourishing of the "open societyOpen society

An open society is a concept originally developed by philosopher Henri Bergson....
" possible.

Life

Karl Popper was born in ViennaVienna

Vienna is the capital of Austria, and also one of the nine States of Austria....
 (then in Austria-HungaryAustria-Hungary

Austria-Hungary, also known as the Austro-Hungarian Empire, Dual Monarchy or k.u.k....
) in 1902 to middle-class parents of JewJew

Jews are followers of Judaism or, more generally, members of the Jewish people , an ethno-religious group descended from th...
ish origins, both of whom had converted to ChristianityFacts About Christianity

Christianity is a monotheistic religion centered on Jesus of Nazareth, and on his life and teachings as presented in the New...
. Popper received a Lutheran upbringing and was educated at the University of ViennaUniversity of Vienna

name =University of Vienna|native_name =Universitt Wien...
.. His father was a bibliophile who had 12,000-14,000 volumes in his personal library. Popper inherited from him both the library and the disposition.

In 1919 he became attracted by MarxismMarxism

Marxism refers to the philosophy and social theory based on Karl Marx's work on one hand, and to the political practice base...
 and subsequently joined the Association of Socialist School Students and also became a member of the Social Democratic Party of AustriaSocial Democratic Party of Austria

The Social Democratic Party of Austria is one of the oldest political parties in Austria....
, which was at that time a party that fully adopted the marxist ideology. He soon became disillusioned by the philosophical restraints imposed by the historical materialismHistorical materialism

Historical materialism is the methodological approach to the study of society, economics and history which was first articul...
 of Marx, abandoned the ideology and remained a passive supporter of social liberalismSocial liberalism

Social liberalism is a development of liberalism stemming from the late 19th century....
 throughout his life.

In 1928 he earned a PhD in Psychology and taught secondary school from 1930 to 1936.
He published his first book, Logik der Forschung (The Logic of Scientific DiscoveryThe Logic of Scientific Discovery Overview

Logik der Forschung is a 1934 book by Karl Popper....
), in 1934. Here, he criticised psychologismPsychologism

Psychologism is a generic type of position in philosophy according to which psychology plays a central role in grounding or ...
, naturalismNaturalism (philosophy)

Naturalism is any of several philosophical stances, typically those descended from materialism and pragmatism, that do not d...
, inductionismFacts About Inductionism

Inductionism is the scientific philosophy where laws are "induced" from sets of data....
, and logical positivismLogical positivism

Logical positivism is a school of philosophy that combines positivism—which states that the only authentic knowledge ...
, and put forth his theory of potential falsifiabilityFalsifiability

In science and the philosophy of science, falsifiability, contingency, and defeasibility are roughly...
 as the criterion demarcating science from non-science.

In 1937, the rise of NazismNazism

National Socialism, commonly shortened to Nazism or Naziism, originated as a fascist movement in Europe, and re...
 and the threat of the AnschlussAnschluss

The Anschluss , also known as the Anschluss sterreichs, was the 1938 annexation of Austria into Greater Germany by the...
 led Popper to emigrate to New ZealandNew Zealand

New Zealand is a country in the south-western Pacific Ocean consisting of two large islands and many much smaller islands, m...
, where he became lecturer in philosophy at Canterbury University CollegeUniversity of Canterbury

name = University of Canterbury...
 New ZealandUniversity of New Zealand

The former University of New Zealand was a New Zealand university from 1870 to 1961, with a federal structure, at various lo...
 (at Christchurch). In 1946, he moved to EnglandEngland

England is the largest and most populous constituent country of the United Kingdom....
 to
become reader in logicLogic

Logic, from Classical Greek ?????, originally meaning the word, or what is spoken, is most often said to be the stud...
 and scientific methodScientific method

Scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting...
 at the London School of EconomicsLondon School of Economics Summary

The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
, where he was appointed professor in 1949. He was president of the Aristotelian SocietyAristotelian Society

The Aristotelian Society for the Systematic Study of Philosophy was founded at a meeting on 19 April 1880 which resolve...
 from 1958 to 1959. He was knightedBritish honours system

The British honours system is a means of rewarding individuals' personal bravery, achievement or service to the United Kingd...
 by Queen Elizabeth IIElizabeth II of the United Kingdom

}|-||}Elizabeth II is the Queen of 16 independent sovereign states known as the Commonwealth Realms....
 in 1965, and was elected a Fellow of the Royal SocietyRoyal Society

The Royal Society of London for the Improvement of Natural Knowledge, known simply as the Royal Society, was founded i...
 in 1976. He retired from academic life in 1969, though he remained intellectually active for the rest of his life. He was invested with the Insignia of a Companion of HonourOrder of the Companions of Honour

The Order of the Companions of Honour is a British and Commonwealth Order....
 in 1982. Popper was a member of the Academy of Humanism and described himself as an agnosticAgnosticism

Agnosticism is the philosophical view that value certain claims as truthparticularly theological claims regarding the existe...
, showing respect for the moral teachings of Judaism and Christianity.

Popper won many awards and honours in his field, including the Lippincott Award of the American Political Science AssociationAmerican Political Science Association

The American Political Science Association was founded in 1903 and is the leading professional organization for the study of...
, the Sonning PrizeSonning Prize

The Sonning Prize is awarded biennially for outstanding contributions to European culture....
, and fellowships in the Royal SocietyRoyal Society

The Royal Society of London for the Improvement of Natural Knowledge, known simply as the Royal Society, was founded i...
, British AcademyBritish Academy

The British Academy is the United Kingdom's national academy for the humanities and the social sciences....
, London School of EconomicsLondon School of Economics

The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
, King's College LondonKing's College London

King's College London is the largest college of the federal University of London, and, having received its royal charter in ...
, and Darwin CollegeFacts About Darwin College, Cambridge

Darwin College is one of the constituent colleges of the University of Cambridge....
 CambridgeUniversity of Cambridge Summary

name = University of Cambridge|latin_name = Universitas Cantabrigiensis...
. Austria awarded him the Grand Decoration of Honour in Gold. He died in 1994. After cremation, Popper's ashes were taken to ViennaVienna

Vienna is the capital of Austria, and also one of the nine States of Austria....
 and buried at Lainz cemetery adjacent to the ORFOrf

Orf can mean:*An animal disease found in sheep and goats: Orf....
 Centre, where his wife Josefine Anna Henninger - who had died in Austria several years before - had already been buried.

Popper's philosophy


Philosophy of Science

Popper coined the term critical rationalismCritical rationalism

Critical rationalism is an epistemological philosophy advanced by Karl Raimund Popper, which is a logical generalization of ...
to describe his philosophy. The term indicates his rejection of classical empiricismEmpiricism

In philosophy generally, empiricism is a theory of knowledge emphasizing the role of experience....
, and of the observationalist-inductivist account of science that had grown out of it. Popper argued strongly against the latter, holding that scientific theories are abstract in nature, and can be tested only indirectly, by reference to their implications. He also held that scientific theory, and human knowledge generally, is irreducibly conjectural or hypothetical, and is generated by the creative imagination in order to solve problems that have arisen in specific historico-cultural settings. Logically, no number of positive outcomes at the level of experimental testing can confirm a scientific theory, but a single counterexample is logically decisive: it shows the theory, from which the implication is derived, to be false. Popper's account of the logical asymmetry between verificationVerification theory

The verification theory is a philosophical theory proposed by the logical positivists of the Vienna Circle....
 and falsifiabilityFalsifiability

In science and the philosophy of science, falsifiability, contingency, and defeasibility are roughly...
 lies at the heart of his philosophy of science. It also inspired him to take falsifiability as his criterion of demarcationDemarcation problem

The demarcation problem in the philosophy of science is about how and where to draw the lines around science....
 between what is and is not genuinely scientific: a theory should be considered scientific if and only if it is falsifiable. This led him to attack the claims of both psychoanalysisPsychoanalysis

'Psychoanalysis' is a family of psychological theories and methods based on the pioneering work of Sigmund Freud....
 and contemporary MarxismMarxism

Marxism refers to the philosophy and social theory based on Karl Marx's work on one hand, and to the political practice base...
 to scientific status, on the basis that the theories enshrined by them are not falsifiable. Popper also wrote extensively against the famous Copenhagen interpretationCopenhagen interpretation

The Copenhagen interpretation is an interpretation of quantum mechanics formulated by Niels Bohr and Werner Heisenberg while...
 of quantum mechanicsQuantum mechanics

Quantum mechanics is a first quantized quantum theory that supersedes classical mechanics at the atomic and subatomic levels...
. He strongly disagreed with Niels BohrNiels Bohr

Niels Bohr was a Danish physicist who made fundamental contributions to understanding atomic structure and quantum mechan...
's instrumentalismInstrumentalism

In the philosophy of science, instrumentalism is the view that concepts and theories are merely useful instruments whose wor...
 and supported Albert EinsteinAlbert Einstein

Albert Einstein was a German-born theoretical physicist....
's realistScientific realism

Scientific realism is a view in the philosophy of science about the nature of scientific success, an answer to the question ...
 approach to scientific theories about the universe. Popper's falsifiability resembles Charles PeirceCharles Peirce

Charles Sanders Peirce, was an American polymath, born in Cambridge, Massachusetts....
's fallibilismFallibilism Summary

Fallibilism is the philosophical doctrine that absolute certainty about knowledge is impossible; or at least that all claims...
. In Of Clocks and Clouds (1966), Popper remarked that he wished he had known of Peirce's work earlier.

In All Life is Problem Solving, Popper sought to explain the apparent progress of scientific knowledge—how it is that our understanding of the universe seems to improve over time. This problem arises from his position that the truth content of our theories, even the best of them, cannot be verified by scientific testing, but can only be falsified. If so, then how is it that the growth of science appears to result in a growth in knowledge? In Popper's view, the advance of scientific knowledge is an evolutionary process characterised by his formula:



In response to a given problem situation (), a number of competing conjectures, or tentative theories (), are systematically subjected to the most rigorous attempts at falsification possible. This process, error elimination (), performs a similar function for science that natural selectionNatural selection

Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduc...
 performs for biological evolution. Theories that better survive the process of refutation are not more true, but rather, more "fit"—in other words, more applicable to the problem situation at hand (). Consequently, just as a species' "biological fit" does not predict continued survival, neither does rigorous testing protect a scientific theory from refutation in the future. Yet, as it appears that the engine of biological evolution has produced, over time, adaptive traits equipped to deal with more and more complex problems of survival, likewise, the evolution of theories through the scientific method may, in Popper's view, reflect a certain type of progress: toward more and more interesting problems (). For Popper, it is in the interplay between the tentative theories (conjectures) and error elimination (refutation) that scientific knowledge advances toward greater and greater problems; in a process very much akin to the interplay between genetic variation and natural selection.

Where does "truth" fit into all this? As early as 1934 Popper wrote of the search for truth as "one of the strongest motives for scientific discovery." Still, he describes in Objective Knowledge (1972) early concerns about the much-criticised notion of truth as correspondenceCorrespondence theory of truth Overview

The correspondence theory of truth states that something is rendered true by the existence of a fact with corresponding elem...
. Then came the semantic theory of truthSemantic theory of truth

The semantic theory of truth holds that any assertion that a proposition is true can be made only as a formal requirement re...
 formulated by the logician Alfred TarskiAlfred Tarski Overview

Alfred Tarski was a logician and mathematician of considerable philosophical importance....
 and published in 1933. Popper writes of learning in 1935 of the consequences of Tarski's theory, to his intense joy. The theory met critical objections to truthTruth

Common dictionary definitions of truth mention some form of accord with fact or reality....
 as correspondence and thereby rehabilitated it. The theory also seemed to Popper to support metaphysical realism and the regulative idea of a search for truth.

According to this theory, the conditions for the truth of a sentence as well as the sentences themselves are part of a metalanguageMetalanguage

In logic and linguistics, a metalanguage is a language used to make statements about other languages....
. So, for example, the sentence "Snow is white" is true if and only if snow is white. Although many philosophers have interpreted, and continue to interpret, Tarski's theory as a deflationary theoryDeflationary theory of truth

The deflationary theory of truth is really a family of theories which all have in common the claim that assertions that pred...
, Popper refers to it as a theory in which "is true" is replaced with "corresponds to the facts." He bases this interpretation on the fact that examples such as the one described above refer to two things: assertions and the facts to which they refer. He identifies Tarski's formulation of the truth conditions of sentences as the introduction of a "metalinguistic predicate" and distinguishes the following cases:

  1. "John called" is true.
  2. "It is true that John called."


The first case belongs to the metalanguage whereas the second is more likely to belong to the object language. Hence, "it is true that" possesses the logical status of a redundancy. "Is true", on the other hand, is a predicate necessary for making general observations such as "John was telling the truth about Phillip."

Upon this basis, along with that of the logical content of assertions (where logical content is inversely proportional to probability), Popper went on to develop his important notion of verisimilitudeVerisimilitude

Verisimilitude is the state or quality of something which exhibits the appearance of truth or reality....
 or "truthlikeness".

The intuitive idea behind verisimilitude is that the assertions or hypotheses of scientific theories can be objectively measured with respect to the amount of truth and falsity that they imply. And, in this way, one theory can be evaluated as more or less true than another on a quantitative basis which, Popper emphasizes forcefully, has nothing to do with "subjective probabilities" or other merely "epistemic" considerations.

The simplest mathematical formulation that Popper gives of this concept can be found in the tenth chapter of Conjectures and RefutationsConjectures and Refutations

Conjectures and Refutations: The Growth of Scientific Knowledge is a book written by philosopher Karl Popper....
.
. Here he defines it as:



where is the verisimilitude of a, is a measure of the content of truth of a, and is a measure of the content of the falsity of a.

Knowledge, for Popper, was objective, both in the sense that it is objectively true (or truthlike), and also in the sense that knowledge has an ontological status (i.e., knowledge as object) independent of the knowing subject (Objective Knowledge: An Evolutionary Approach, 1972). He proposed three worlds (see Popperian cosmologyPopperian cosmology Overview

Popperian cosmology is Karl Popper's philosophical theory of reality that includes three interacting worlds, called World...
): World One, being the physical world, or physical states; World Two, being the world of mind, or mental states, ideas, and perceptions; and World Three, being the body of human knowledge expressed in its manifold forms, or the products of the second world made manifest in the materials of the first world (i.e.–books, papers, paintings, symphonies, and all the products of the human mind). World Three, he argued, was the product of individual human beings in exactly the same sense that an animal path is the product of individual animals, and that, as such, has an existence and evolution independent of any individual knowing subjects. The influence of World Three, in his view, on the individual human mind (World Two) is at least as strong as the influence of World One. In other words, the knowledge held by a given individual mind owes at least as much to the total accumulated wealth of human knowledge, made manifest, as to the world of direct experience. As such, the growth of human knowledge could be said to be a function of the independent evolution of World Three. Many contemporary philosophers have not embraced Popper's Three World conjecture, due mostly, it seems, to its resemblance to Cartesian dualism.

Political philosophy

In The Open Society and Its EnemiesThe Open Society and Its Enemies

The Open Society and Its Enemies is an influential two-volume work by Karl Popper written during World War II....
and The Poverty of Historicism, Popper developed a critique of historicismHistoricism

Historicism is a term which applies to a number of theories of culture or historical development which place the greatest we...
 and a defence of the 'Open Society'. Historicism is the theory that history develops inexorably and necessarily according to knowable general laws towards a determinate end. Popper argued that this view is the principal theoretical presupposition underpinning most forms of authoritarianismAuthoritarianism

This article applies to political ideologies....
 and totalitarianismTotalitarianism

Totalitarianism is a term employed by political scientists, especially those in the field of comparative politics, to descri...
. He argued that historicism is founded upon mistaken assumptions regarding the nature of scientific law and prediction. Since the growth of human knowledge is a causal factor in the evolution of human history, and since "no society can predict, scientifically, its own future states of knowledge", it follows, he argued, that there can be no predictive science of human history. For Popper, metaphysical and historical indeterminism go hand in hand.

Problem of Induction

Among his contributions to philosophy is his attempt to answer the philosophical problem of inductionProblem of induction

The problem of induction is the philosophical issue involved in deciding the place of induction in determining empirical tru...
. The problem, in basic terms, can be understood by example: given that the sun has risen every day for as long as anyone can remember, what is the rational proof that it will rise tomorrow? How can one rationally prove that past events will continue to repeat in the future, just because they have repeated in the past? Popper's reply is characteristic, and ties in with his criterion of falsifiability. He states that while there is no way to prove that the sun will rise, we can formulate a theory that every day the sun will rise—if it does not rise on some particular day, our theory will be disproved, but at present it is confirmed. Since it is a very well-tested theory, we have every right to believe that it accurately represents reality, so far as we know.

This may be a true description of the pragmatic approach to knowledge adopted by the scientific method, but it does not in itself address the philosophical problem. As Stephen HawkingStephen Hawking

Stephen William Hawking, CH, CBE, FRS is a theoretical physicist....
 explains, "No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory." It may be pragmatically useful to accept a well-tested theory as true until it is falsified, but this does not solve the philosophical problem of induction. As Bertrand RussellBertrand Russell Overview

Bertrand Arthur William Russell, 3rd Earl Russell, OM, FRS , was a British philosopher, logician, and mathematician, working...
 put it, "the general principles of science . . . are believed because mankind have found innumerable instances of their truth and no instances of their falsehood. But this affords no evidence for their truth in the future, unless the inductive principle is assumed." In essence, Popper addressed justification for belief ("why do you believe") that the sun will rise tomorrow, not justification for the fact ("how do you know") that it will, which is the crux of the philosophical problem. Said another way, Popper addressed the psychological causes of our belief in the validity of induction without trying to provide logical reasons for it. In this way, he provided a psychological account of the use of induction, but left the philosophical ground of induction as a valid mode of knowledge unaccounted for.

Influence

By all accounts, Popper has played a vital role in establishing the philosophy of sciencePhilosophy of science

Philosophy of science is the branch of philosophy that studies the philosophical assumptions, foundations, and implications ...
 as a vigorous, autonomous discipline within analytic philosophyAnalytic philosophy

Analytic philosophy is the dominant academic philosophical movement in English-speaking countries and in the Nordic countri...
, through his own prolific and influential works, and also through his influence on his own contemporaries and students. Popper founded in 1946 the Department of Philosophy, Logic and Scientific Method at the London School of EconomicsLondon School of Economics

The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
 and there lectured and influenced both Imre LakatosImre Lakatos

Imre Lakatos was a philosopher of mathematics and of science. ...
 and Paul FeyerabendFacts About Paul Feyerabend

Paul Karl Feyerabend was an Austrian-born philosopher of science who lived in England, the United States, New Zealand, Ital...
, two of the foremost philosophers of science in the next generation of philosophy of science. (Lakatos significantly modified Popper's position, and Feyerabend repudiated it entirely, but the work of both is deeply influenced by Popper and engaged with many of the problems that Popper set.)

While there is some dispute as to the matter of influence, Popper had a long-standing and close friendship with economist Friedrich HayekFriedrich Hayek

Friedrich August von Hayek, CH was an Austrian-born British economist and political philosopher....
, who was also brought to the London School of EconomicsLondon School of Economics

The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
 from Vienna. Each found support and similarities in each other's work, citing each other often, though not without qualification. In a letter to Hayek in 1944, Popper stated, "I think I have learnt more from you than from any other living thinker, except perhaps Alfred TarskiAlfred Tarski

Alfred Tarski was a logician and mathematician of considerable philosophical importance....
." (See Hacohen, 2000). Popper dedicated his Conjectures and RefutationsConjectures and Refutations

Conjectures and Refutations: The Growth of Scientific Knowledge is a book written by philosopher Karl Popper....
to Hayek. For his part, Hayek dedicated a collection of papers, Studies in Philosophy, Politics, and Economics, to Popper, and in 1982 said, "...ever since his Logik der Forschung first came out in 1934, I have been a complete adherent to his general theory of methodology." (See Weimer and Palermo, 1982).

Popper also had long and mutually influential friendships with art historian Ernst GombrichErnst Gombrich

Sir Ernst Hans Josef Gombrich CBE, was an art historian, who spent most of his working life in the United Kingdom....
, biologist Peter MedawarPeter Medawar

Sir Peter Brian Medawar was a Brazilian-born English scientist best known for his work on how the immune system rejects or a...
, and neuro-scientist John Carew EcclesJohn Carew Eccles

Sir John Carew Eccles was an Australian neurophysiologist who won the 1963 Nobel Prize in Physiology or Medicine for his wo...
.

Popper's influence, both through his work in philosophy of science and through his political philosophy, has also extended beyond the academy. Among Popper's students and advocates at the London School of EconomicsFacts About London School of Economics

The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
 is the multibillionaire investor George SorosGeorge Soros

George Soros is a financial speculator, stock investor, liberal political activist, and philanthropist....
, who says his investment strategies are modelled on Popper's understanding of the advancement of knowledge through falsificationFalsifiability

In science and the philosophy of science, falsifiability, contingency, and defeasibility are roughly...
. Among Soros's philanthropicPhilanthropy

Philanthropy is the act of donating money or goods, or volunteering one's time and effort, to support a charitable cause, us...
 foundations is the Open Society InstituteOpen Society Institute

The Open Society Institute, a private operating and grantmaking foundation, aims to shape public policy to promote democrati...
, a think-tank named in honour of Popper's The Open Society and Its EnemiesThe Open Society and Its Enemies

The Open Society and Its Enemies is an influential two-volume work by Karl Popper written during World War II....
, which Soros founded to advance the Popperian defense of the open societyOpen society

An open society is a concept originally developed by philosopher Henri Bergson....
 against authoritarianismAuthoritarianism

This article applies to political ideologies....
 and totalitarianismTotalitarianism

Totalitarianism is a term employed by political scientists, especially those in the field of comparative politics, to descri...
.

Popperian philosophy also inspired the creation of Taking Children SeriouslyTaking Children Seriously

Taking Children Seriously, TCS, is a worldwide parenting movement and educational philosophy based upon the idea that ...
, a movement arguing that children and adults should try to resolve their differences without coercion.

Critics


Criticism of his philosophy of science


Most criticisms of Popper's philosophy are of the falsification, or error elimination, element in his account of problem solving. In interpreting these, it is important to bear in mind the aims of his idea. It is intended as an ideal, practical method of effective human problem solving; as such, the current conclusions of science are stronger than pseudo-sciences or non-sciences, insofar as they have survived this particularly vigorous selection method. He does not argue that any such conclusions are therefore true, or that this describes the actual methods of any particular scientist.

Rather, it is a recommended ideal method that, if enacted by a system or community, will over time lead to slow but steady progress of a sort (relative to how well the system or community enacts the method). It has been suggested that Popper's ideas are often mistaken for a hard logical account of truth because of the historical co-incidence of their appearing at the same time as logical positivismLogical positivism Overview

Logical positivism is a school of philosophy that combines positivism—which states that the only authentic knowledge ...
, the followers of which mistook his aims for their own (Brian Magee 1973: Popper (Modern Masters series).

The Quine-Duhem thesisConfirmation holism

Confirmation holism, also called epistemological holism is the claim that a scientific theory cannot be tested in isolat...
 argues that it's impossible to test a single hypothesis on its own, since each one comes as part of an environment of theories. Thus we can only say that the whole package of relevant theories has been collectively falsified, but cannot conclusively say which element of the package must be replaced. An example of this is given by the discovery of the planet Neptune: when the motion of Uranus was found not to match the predictions of Newton's laws, the theory "There are seven planets in the solar system" was rejected, and not Newton's laws themselves. Popper discussed this critique of naïve falsificationismFalsifiability

In science and the philosophy of science, falsifiability, contingency, and defeasibility are roughly...
 in Chapters 3 & 4 of The Logic of Scientific DiscoveryThe Logic of Scientific Discovery

Logik der Forschung is a 1934 book by Karl Popper....
. For Popper, theories are accepted or rejected via a sort of 'natural selection'. Theories that say more about the way things appear are to be preferred over those that do not; the more generally applicable a theory is, the greater its value. Thus Newton’s laws, with their wide general application, are to be preferred over the much more specific “the solar system has seven planets”.

Thomas Kuhn’s influential book The Structure of Scientific RevolutionsThe Structure of Scientific Revolutions

The Structure of Scientific Revolutions is an analysis of the history of science....
argued that scientists work in a series of paradigmParadigm

Since the late 1960s, the word paradigm has referred to a thought pattern in any scientific discipline or other epistemologi...
s, and found little evidence of scientists actually following a falsificationist methodology. Popper's student Imre LakatosImre Lakatos

Imre Lakatos was a philosopher of mathematics and of science. ...
 attempted to reconcile Kuhn’s work with falsificationism by arguing that science progresses by the falsification of research programs rather than the more specific universal statementsUniversal quantification

In predicate logic, universal quantification is an attempt to formalise the notion that something is true for everything...
 of naïve falsificationism. Another of Popper’s students Paul FeyerabendPaul Feyerabend

Paul Karl Feyerabend was an Austrian-born philosopher of science who lived in England, the United States, New Zealand, Ital...
 ultimately rejected any prescriptive methodology, and argued that the only universal method characterizing scientific progress was anything goes.

Popper seems to have anticipated Kuhn's observations. In his collection Conjectures and RefutationsConjectures and Refutations

Conjectures and Refutations: The Growth of Scientific Knowledge is a book written by philosopher Karl Popper....
: The Growth of Scientific Knowledge
(Harper & Row, 1963), Popper writes, "Science must begin with myths, and with the criticism of myths; neither with the collection of observations, nor with the invention of experiments, but with the critical discussion of myths, and of magical techniques and practices. The scientific tradition is distinguished from the pre-scientific tradition in having two layers. Like the latter, it passes on its theories; but it also passes on a critical attitude towards them. The theories are passed on, not as dogmas, but rather with the challenge to discuss them and improve upon them."

Another objection is that it is not always possible to demonstrate falsehood definitively, especially if one is using statisticalStatistical significance

In statistics, a result is significant if it is unlikely to have occurred by chance, if in reality the independent variable ...
 criteria to evaluate a null hypothesisNull hypothesis

In statistics, a null hypothesis is a hypothesis set up to be nullified or refuted in order to support an alternative hypo...
. More generally, it is not always clear that if evidence contradicts a hypothesis that this is a sign of flaws in the hypothesis rather than of flaws in the evidence. However, this is a misunderstanding of what Popper's philosophy of science sets out to do. Rather than offering a set of instructions that merely need to be followed diligently to achieve science, Popper makes it clear in The Logic of Scientific DiscoveryThe Logic of Scientific Discovery

Logik der Forschung is a 1934 book by Karl Popper....
that his belief is that the resolution of conflicts between hypotheses and observations can only be a matter of the collective judgment of scientists, in each individual case.

Popper's falsificationism can be questioned logically, by asking about statements such as "There are black holeBlack hole

A black hole is an object predicted by general relativity with a gravitational field so strong that nothing can escape it n...
s", which cannot be falsified by any possible observation, yet which seems to be a legitimately scientific claim. Similarly, it's not clear how Popper would deal with a statement like "for every metal, there is a temperature at which it will melt", which can neither be confirmed nor falsified by any possible observation, yet which seems to be a valid scientific hypothesis. These examples were pointed out by Carl Gustav HempelCarl Gustav Hempel

Carl Gustav Hempel was a philosopher of science and a major figure in 20th-century logical positivism....
. Hempel came to acknowledge that Logical Positivism's verificationism was untenable, but argued that falsificationism was equally untenable on logical grounds alone. The simplest response to this is that, because Popper describes how theories attain, maintain and lose scientific status, individual consequences of currently accepted scientific theories are scientific in the sense of being part of tentative scientific knowledge, and both of Hempel's examples fall under this category. For instance, atomic theoryAtomic theory

In chemistry and physics, atomic theory is a theory of the nature of matter....
 implies that all metals melt at some temperature.

Other criticisms


Other critics seek to vindicate the claims of historicismHistoricism

Historicism is a term which applies to a number of theories of culture or historical development which place the greatest we...
 or holismHolism

Holism is the idea that all the properties of a given system cannot be determined or explained by the sum of its component p...
 to intellectual respectability, or psychoanalysisPsychoanalysis

'Psychoanalysis' is a family of psychological theories and methods based on the pioneering work of Sigmund Freud....
 or MarxismMarxism

Marxism refers to the philosophy and social theory based on Karl Marx's work on one hand, and to the political practice base...
 to scientific status. It has been argued that Popper's student Imre LakatosImre Lakatos Summary

Imre Lakatos was a philosopher of mathematics and of science. ...
, for example, transformed Popper's philosophy using historicist and updated Hegelian historiographic ideas. (subscription and/or fee required)

Charles TaylorCharles Taylor (philosopher)

Charles Margrave Taylor, CC, BA, MA, Ph.D, FRSC is a Canadian philosopher known for his viewpoints on morality and modern we...
 accuses Popper of exploiting his worldwide fame as an epistemologist to diminish the importance of philosophers of the 20th century continental traditionContinental philosophy

Continental philosophy is a term used in philosophy to designate one of two major "traditions" of current Western philosophy...
. According to Taylor, Popper's criticisms are completely baseless, but they are received with an attention and respect that Popper's "intrinsic worth hardly merits". William W. Bartley defended Popper against such allegations: "Sir Karl Popper is not really a participant in the contemporary professional philosophical dialogue; quite the contrary, he has ruined that dialogue. If he is on the right track, then the majority of professional philosophers the world over has wasted or is wasting their intellectual careers. The gulf between Popper's way of doing philosophy and that of the bulk of professional philosophers is as great as that between astronomy and astrology."(deposit account required)

In 2004 philosopher and psychologistPsychologist

A psychologist is a scientist and/or clinician who studies psychology, the systematic investigation of the human mind, inclu...
 Michel ter Hark|Groningen]], The Netherlands) published a book, called Popper, Otto Selz and the rise of evolutionary epistemology, ISBN 0521830745, in which he claimed that Popper took some of his ideas from his tutor, the German-Jewish psychologist Otto SelzOtto Selz

Otto Selz, was a German psychologist who formulated the first nonassociationist theory of thinking, in 1913....
. Selz himself never published his ideas, partly because of the rise of NazismNazism

National Socialism, commonly shortened to Nazism or Naziism, originated as a fascist movement in Europe, and re...
 which forced him to quit his work in 1933, and the prohibition of referring to Selz' work.

See also

  • Popperian cosmologyPopperian cosmology

    Popperian cosmology is Karl Popper's philosophical theory of reality that includes three interacting worlds, called World...
  • Evolutionary epistemologyEvolutionary epistemology

    Evolutionary epistemology is a branch of epistemology that applies the concepts of biological evolution to the growth of hum...
  • LiberalismLiberalism Overview

    Liberalism is an ideology, philosophical view, and political tradition which holds that liberty is the primary political val...
  • Liberalism in AustriaLiberalism in Austria

    This article gives an overview of liberalism in Austria....
  • Contributions to liberal theoryContributions to liberal theory

    Contributions to liberal theory is a partial list of individual contributions on a worldwide scale....
  • Calculus of predispositionsCalculus of predispositions

    Calculus of Predispositions is a basic part of Predispositioning Theory belongs to the indeterministic procedures....
  • Predispositioning TheoryPredispositioning Theory

    Predispositioning Theory was founded by Aron Katsenelinboigen, a Professor in Wharton School who dealt with indeterministic ...
  • Popper's experimentPopper's experiment

    Popper's experiment is an experiment proposed by the 20th century philosopher of science Karl Popper, to test the standard interpr...
     (quantum mechanics)

Bibliography

  • The Two Fundamental Problems of the Theory of Knowledge, 1930–33 (as a typescript circulating as Die beiden Grundprobleme der Erkenntnistheorie; as a German book 1979, as English translation 2008), ISBN 0415394317
  • The Logic of Scientific DiscoveryThe Logic of Scientific Discovery

    Logik der Forschung is a 1934 book by Karl Popper....
    , 1934 (as Logik der Forschung, English translation 1959), ISBN 0415278449
  • The Poverty of Historicism, 1936 (private reading at a meeting in Brussels, 1944/45 as a series of journal articles in Econometrica, 1957 a book), ISBN 0415065690
  • The Open Society and Its EnemiesThe Open Society and Its Enemies Summary

    The Open Society and Its Enemies is an influential two-volume work by Karl Popper written during World War II....
    , 1945 Vol 1 ISBN 0415290635, Vol 2 ISBN 0415290635
  • Quantum Theory and the Schism in Physics, 1956/57 (as privately circulated galley proofs; published as a book 1982), ISBN 0415091128
  • The Open Universe: An Argument for Indeterminism, 1956/57 (as privately circulated galley proofs; published as a book 1982), ISBN 0415078652
  • Realism and the Aim of Science, 1956/57 (as privately circulated galley proofs; published as a book 1983), ISBN 0091514509
  • Conjectures and RefutationsConjectures and Refutations

    Conjectures and Refutations: The Growth of Scientific Knowledge is a book written by philosopher Karl Popper....
    : The Growth of Scientific Knowledge
    , 1963, ISBN 0415043182
  • Objective Knowledge: An Evolutionary Approach, 1972, Rev. ed., 1979, ISBN 0198750242
  • Unended Quest; An Intellectual Autobiography, 1976, ISBN 0415285909
  • The Self and Its Brain: An Argument for Interactionism (with Sir John C. Eccles), 1977, ISBN 0415058988
  • article by Popper, Dialectica 1978
  • In Search of a Better World, 1984, a collection of Popper’s essays and lectures covering a range of subjects from the beginning of scientific speculation in classical Greece to the need for a new professional ethic based on the ideas of tolerance and intellectual responsibility; "All things living are in search of a better world."; Karl Popper, from the Preface of the book. ISBN 0415135486
  • Die Zukunft ist offen (The Future is Open) (with Konrad LorenzKonrad Lorenz

    Konrad Zacharias Lorenz was an Austrian zoologist, animal psychologist, and ornithologist....
    ), 1985 (in German), ISBN 349200640X
  • A World of Propensities, 1990, ISBN 1855060000
  • The Lesson of this Century, Interviewer: Giancarlo Bosetti, English translation: Patrick Camiller), 1992, ISBN 0415129583
  • All life is Problem Solving, 1994, ISBN 0415249929
  • The Myth of the Framework: In Defence of Science and Rationality, (Edited by Mark Amadeus Notturno) 1994, ISBN 0415135559
  • Knowledge and the Mind-Body Problem: In Defence of Interactionism, (Edited by Mark Amadeus Notturno) 1994
  • The World of Parmenides, Essays on the Presocratic Enlightenment, 1998, (Edited by Arne F. Petersen with the assistance of Jørgen Mejer), ISBN 0415173019
  • Frühe Schriften, 2006 (Edited by Troels Eggers Hansen, includes Popper's writings and publications from before the Logic, including his previously unpublished thesis, dissertation and journal articles published that relate to the Wiener Schulreform)
  • After 'The Open Society': Selected Social and Political Writings, 2008 (Edited by Jeremy Shearmur and Piers Norris Turner, it includes previously unpublished and uncollected essays), ISBN 0415309085


Further reading

  • [Comprehensive bibliography:] Lube, Manfred: Karl R. Popper. Bibliographie 1925–2004. Wissenschaftstheorie, Sozialphilosophie, Logik, Wahrscheinlichkeitstheorie, Naturwissenschaften. Frankfurt/Main etc.: Peter Lang, 2005. 576 pp. (Schriftenreihe der Karl Popper Foundation Klagenfurt.3.)
  • David MillerDavid Miller (philosopher)

    David W. Miller teaches philosophy at the University of Warwick in Coventry, UK....
    . Critical Rationalism: A Restatement and Defence. 1994.
  • David MillerDavid Miller (philosopher)

    David W. Miller teaches philosophy at the University of Warwick in Coventry, UK....
     (Ed.). Popper Selections.
  • John W. N. Watkins. Science and Skepticism. 1984.
  • Bartley, William Warren III. Unfathomed Knowledge, Unmeasured Wealth. La Salle, IL: Open Court Press 1990. A look at Popper and his influence by one of his students.
  • Edmonds, D., Eidinow, J. Wittgenstein's Poker. New York: Ecco 2001. A review of the origin of the conflict between Popper and Ludwig WittgensteinLudwig Wittgenstein

    Ludwig Josef Johann Wittgenstein was an Austrian philosopher who contributed several ground-breaking works to contemporary...
    , focused on events leading up to their volatile first encounter at 1946 Cambridge meeting.
  • Feyerabend, Paul Against Method. London: New Left Books, 1975. A polemical, iconoclastic book by a former colleague of Popper's. Vigorously critical of Popper's rationalist view of science.
  • Hacohen, M. Karl Popper: The Formative Years, 1902 – 1945. Cambridge: Cambridge University Press, 2000.
  • Hickey, J. Thomas. Book V, Karl Popper And Falsificationist Criticism. www.philsci.com . 1995* Kadvany, John Imre Lakatos and the Guises of Reason. Durham and London: Duke University Press, 2001. ISBN 0-8223-2659-0. Explains how Imre Lakatos developed Popper's philosophy into a historicist and critical theory of scientific method.
  • Kuhn, Thomas S. The Structure of Scientific Revolutions. Chicago: University of Chicago Press, 1962. Central to contemporary philosophy of science is the debate between the followers of Kuhn and Popper on the nature of scientific enquiry. This is the book in which Kuhn's views received their classical statement.
  • Levinson, PaulPaul Levinson

    Paul Levinson BA, MA, PhD is an author and professor of communications and media studies at Fordham University in New Yo...
    , ed. In Pursuit of Truth: Essays on the Philosophy of Karl Popper on the Occasion of his 80th Birthday. Atlantic Highlands, NJ: Humanities Press, 1982. A collection of essays on Popper's thought and legacy by a wide range of his followers. Includes an interview with Sir Ernst GombrichErnst Gombrich

    Sir Ernst Hans Josef Gombrich CBE, was an art historian, who spent most of his working life in the United Kingdom....
    .
  • Magee, Bryan. Popper. London: Fontana, 1977. An elegant introductory text. Very readable, albeit rather uncritical of its subject, by a former Member of Parliament.
  • Magee, Bryan. Confessions of a Philosopher, Weidenfeld and Nicolson, 1997. Magee's philosophical autobiography, with a chapter on his relations with Popper. More critical of Popper than in the previous reference.
  • Munz, Peter. Beyond Wittgenstein's Poker: New Light on Popper and Wittgenstein Aldershot, Hampshire, UK: Ashgate, 2004. ISBN 0-7546-4016-7. Written by the only living student of both Wittgenstein and Popper, an eyewitness to the famous "poker" incident described above (Edmunds & Eidinow). Attempts to synthesize and reconcile the differences between these two philosophers.
  • Notturno, Mark Amadeus. "Objectivity, Rationality, and the Third Realm: Justification and the Grounds of Psychologism". Boston: Martinus Nijhoff, 1985.
  • Notturno, Mark Amadeus. On Popper. Wadsworth Philosophers Series. 2003. A very comprehensive book on Popper’s philosophy by an accomplished Popperian.
  • Notturno, Mark Amadeus. "Science and the Open Society". New York: CEU Press, 2000.
  • O'Hear, Anthony. Karl Popper. London: Routledge, 1980. A critical account of Popper's thought, viewed from the perspective of contemporary analytic philosophy.
  • Radnitzky, Gerard, Bartley, W. W., III eds. Evolutionary Epistemology, Rationality, and the Sociology of Knowledge. La Salle, IL: Open Court Press 1987. ISBN 0-8126-9039-7. A strong collection of essays by Popper, Campbell, Munz, Flew, et al, on Popper's epistemology and critical rationalism. Includes a particularly vigorous answer to Rorty's criticisms.
  • Richmond, Sheldon. Aesthetic Criteria: Gombrich and the Philosophies of Science of Popper and Polanyi. Rodopi, Amsterdam/Atlanta, 1994, 152 pp. ISBN 90-5183-618-X.
  • Schilpp, Paul A., ed. The Philosophy of Karl Popper, 2 vols. La Salle, IL: Open Court Press, 1974. One of the better contributions to the Library of Living Philosophers series. Contains Popper's intellectual autobiography, a comprehensive range of critical essays, and Popper's responses to them.
  • Schroeder-Heister, P. "Popper, Karl Raimund (1902–94)," International Encyclopedia of the Social & Behavioral SciencesInternational Encyclopedia of the Social & Behavioral Sciences

    The International Encyclopedia of the Social & Behavioral Sciences , edited by Neil J....
    , 2001, pp. 11727-11733.
  • Stokes, G. Popper: Philosophy, Politics and Scientific Method. Cambridge: Polity Press, 1998. A very comprehensive, balanced study, which focuses largely on the social and political side of Popper's thought.
  • Stove, D.C.David Stove

    David Charles Stove, was an Australian philosopher of science, and essayist in the popular press....
    , Popper and AfterPopper and After

    Popper and After is a book by David Charles Stove first published by Pergamon Press in 1982....
    : Four Modern Irrationalists
    . Oxford: Pergamon. 1982. A vigorous attack, especially on Popper's restricting himself to deductive logic.
  • Thornton, Stephen. Stanford Encyclopedia of PhilosophyFacts About Stanford Encyclopedia of Philosophy

    The Stanford Encyclopedia of Philosophy is a free online encyclopedia of philosophy run and maintained by Stanford Universit...
    ,
    2006.
  • Weimer, W., Palermo, D., eds. Cognition and the Symbolic Processes. Hillsdale, NJ: Lawrence Erlbaum Associates. 1982. See Hayek's essay, "The Sensory Order after 25 Years", and "Discussion".


External links

  • from
  • from
  • includes complete bibliography 1925-1999
  • International Association for the Promotion of Science and Research, in German
  • brief biography of Popper
  • George Soros foundations network
  • by Martin GardnerMartin Gardner

    Martin Gardner is a popular American mathematics and science writer specializing in recreational mathematics, but with inte...
  • by J C Lester.
  • Site maintained by John Kadvany, PhD.
  • by Peter SingerPeter Singer

    Peter Albert David Singer is an Australian philosopher....
     The New York Review of Books, vol. 21, no. 7 (May 2, 1974)
  • Persian translation by Khosro NaghedKhosro Naghed

    Khosro Naghed is a notable Persian scholar, Iranologist and linguist....
  • , BBC Radio 4BBC Radio 4

    BBC Radio 4 is a British domestic radio station which broadcasts a wide variety of chiefly spoken-word programmes including ...
     programme, In Our TimeIn Our Time (BBC Radio 4)

    In Our Time is a discussion programme hosted by Melvyn Bragg on BBC Radio 4 in Great Britain....
    , 8 February 2007. Discussion with John Worrall, Professor of Philosophy of Science at the London School of EconomicsLondon School of Economics

    The London School of Economics and Political Science, more commonly referred to as The London School of Economics or '...
    , Anthony O'Hear, Weston Professor of Philosophy at Buckingham UniversityUniversity of Buckingham

    The University of Buckingham is the UK's first and only Private University....
    , Nancy Cartwright, Professor of Philosophy at the LSE and the University of CaliforniaUniversity of California

    The University of California is a public university system in the state of California....
    , hosted by Melvyn BraggMelvyn Bragg

    Melvyn Bragg, Baron Bragg, FRSL, FRTS is a British author and broadcaster....
    .
  • Site offers free downloads by chapter available for public use.
  • This is a microfilm copy of the Stanford University Popper Archive of Popper's papers to whose catalogue a weblink is provided.
  • (Karl Popper Archive at University Library Klagenfurt. Consists of Popper's Library and paper copies of the Popper Papers at The Hoover Institution Archive at Stanford, Cal.)
  • (Austrian Karl R. Popper Research Association - University of Graz, Austria)