
Originally, fallibilism (from Medieval Latin: fallibilis, "liable to error") is the philosophical principle that propositions can be accepted even though they cannot be conclusively proven or justified, or that neither knowledge nor belief is certain. The term was coined in the late nineteenth century by the American philosopher Charles Sanders Peirce, as a response to foundationalism. Theorists, following Austrian-British philosopher Karl Popper, may also refer to fallibilism as the notion that knowledge might turn out to be false. Furthermore, fallibilism is said to imply corrigibilism, the principle that propositions are open to revision. Fallibilism is often juxtaposed with infallibilism.

Infinite regress and infinite progress
According to philosopher Scott F. Aikin, fallibilism cannot properly function in the absence of infinite regress. The term, usually attributed to Pyrrhonist philosopher Agrippa, is argued to be the inevitable outcome of all human inquiry, since every proposition requires justification. Infinite regress, also represented within the regress argument, is closely related to the problem of the criterion and is a constituent of the Münchhausen trilemma. Illustrious examples regarding infinite regress are the cosmological argument, turtles all the way down, and the simulation hypothesis. Many philosophers struggle with the metaphysical implications that come along with infinite regress. For this reason, philosophers have gotten creative in their quest to circumvent it.
Somewhere along the seventeenth century, English philosopher Thomas Hobbes set forth the concept of "infinite progress". With this term, Hobbes had captured the human proclivity to strive for perfection. Philosophers like Gottfried Wilhelm Leibniz, Christian Wolff, and Immanuel Kant, would elaborate further on the concept. Kant even went on to speculate that immortal species should hypothetically be able to develop their capacities to perfection.
Already in 350 B.C.E, Greek philosopher Aristotle made a distinction between potential and actual infinities. Based on his discourse, it can be said that actual infinities do not exist, because they are paradoxical. Aristotle deemed it impossible for humans to keep on adding members to finite sets indefinitely. It eventually led him to refute some of Zeno's paradoxes. Other relevant examples of potential infinities include Galileo's paradox and the paradox of Hilbert's hotel. The notion that infinite regress and infinite progress only manifest themselves potentially pertains to fallibilism. According to philosophy professor Elizabeth F. Cooke, fallibilism embraces uncertainty, and infinite regress and infinite progress are not unfortunate limitations on human cognition, but rather necessary antecedents for knowledge acquisition. They allow us to live functional and meaningful lives.
Critical rationalism
In the mid-twentieth century, several important philosophers began to critique the foundations of logical positivism. In his work The Logic of Scientific Discovery (1934), Karl Popper, the founder of critical rationalism, argued that scientific knowledge grows from falsifying conjectures rather than any inductive principle and that falsifiability is the criterion of a scientific proposition. The claim that all assertions are provisional and thus open to revision in light of new evidence is widely taken for granted in the natural sciences.
Furthermore, Popper defended his critical rationalism as a normative and methodological theory, that explains how objective, and thus mind-independent, knowledge ought to work. Hungarian philosopher Imre Lakatos built upon the theory by rephrasing the problem of demarcation as the problem of normative appraisal. Lakatos' and Popper's aims were alike, that is finding rules that could justify falsifications. However, Lakatos pointed out that critical rationalism only shows how theories can be falsified, but it omits how our belief in critical rationalism can itself be justified. The belief would require an inductively verified principle. When Lakatos urged Popper to admit that the falsification principle cannot be justified without embracing induction, Popper did not succumb. Lakatos' critical attitude towards rationalism has become emblematic for his so called critical fallibilism. While critical fallibilism strictly opposes dogmatism, critical rationalism is said to require a limited amount of dogmatism. Though, even Lakatos himself had been a critical rationalist in the past, when he took it upon himself to argue against the inductivist illusion that axioms can be justified by the truth of their consequences. In summary, despite Lakatos and Popper picking one stance over the other, both have oscillated between holding a critical attitude towards rationalism as well as fallibilism.
Fallibilism has also been employed by philosopher Willard V. O. Quine to attack, among other things, the distinction between analytic and synthetic statements. British philosopher Susan Haack, following Quine, has argued that the nature of fallibilism is often misunderstood, because people tend to confuse fallible propositions with fallible agents. She claims that logic is revisable, which means that analyticity does not exist and necessity (or a priority) does not extend to logical truths. She hereby opposes the conviction that propositions in logic are infallible, while agents can be fallible. Critical rationalist Hans Albert argues that it is impossible to prove any truth with certainty, not only in logic, but also in mathematics.
Mathematical fallibilism
In Proofs and Refutations: The Logic of Mathematical Discovery (1976), philosopher Imre Lakatos implemented mathematical proofs into what he called Popperian "critical fallibilism". Lakatos's mathematical fallibilism is the general view that all mathematical theorems are falsifiable. Mathematical fallibilism deviates from traditional views held by philosophers like Hegel, Peirce, and Popper. Although Peirce introduced fallibilism, he seems to preclude the possibility of us being mistaken in our mathematical beliefs. Mathematical fallibilism appears to uphold that even though a mathematical conjecture cannot be proven true, we may consider some to be good approximations or estimations of the truth. This so called verisimilitude may provide us with consistency amidst an inherent incompleteness in mathematics. Mathematical fallibilism differs from quasi-empiricism, to the extent that the latter does not incorporate inductivism, a feature considered to be of vital importance to the foundations of set theory.
In the philosophy of mathematics, a central tenet of fallibilism is undecidability (which bears resemblance to the notion of isostheneia, or "equal veracity"). Two distinct types of the word "undecidable" are currently being applied. The first one relates, most notably, to the continuum hypothesis, which was proposed by mathematician Georg Cantor in 1873. The continuum hypothesis represents a tendency for infinite sets to allow for undecidable solutions — solutions which are true in one constructible universe and false in another. Both solutions are independent from the axioms in Zermelo–Fraenkel set theory combined with the axiom of choice (also called ZFC). This phenomenon has been labeled the independence of the continuum hypothesis. Both the hypothesis and its negation are thought to be consistent with the axioms of ZFC. Many noteworthy discoveries have preceded the establishment of the continuum hypothesis.
In 1877, Cantor introduced the diagonal argument to prove that the cardinality of two finite sets is equal, by putting them into a one-to-one correspondence. Diagonalization reappeared in Cantors theorem, in 1891, to show that the power set of any countable set must have strictly higher cardinality. The existence of the power set was postulated in the axiom of power set; a vital part of Zermelo–Fraenkel set theory. Moreover, in 1899, Cantor's paradox was discovered. It postulates that there is no set of all cardinalities. Two years later, polymath Bertrand Russell would invalidate the existence of the universal set by pointing towards Russell's paradox, which implies that no set can contain itself as an element (or member). The universal set can be confuted by utilizing either the axiom schema of separation or the axiom of regularity. In contrast to the universal set, a power set does not contain itself. It was only after 1940 that mathematician Kurt Gödel showed, by applying inter alia the diagonal lemma, that the continuum hypothesis cannot be refuted, and after 1963, that fellow mathematician Paul Cohen revealed, through the method of forcing, that the continuum hypothesis cannot be proved either. In spite of the undecidability, both Gödel and Cohen suspected dependence of the continuum hypothesis to be false. This sense of suspicion, in conjunction with a firm belief in the consistency of ZFC, is in line with mathematical fallibilism. Mathematical fallibilists suppose that new axioms, for example the axiom of projective determinacy, might improve ZFC, but that these axioms will not allow for dependence of the continuum hypothesis.
The second type of undecidability is used in relation to computability theory (or recursion theory) and applies not solely to statements but specifically to decision problems; mathematical questions of decidability. An undecidable problem is a type of computational problem in which there are countably infinite sets of questions, each requiring an effective method to determine whether an output is either "yes or no" (or whether a statement is either "true or false"), but where there cannot be any computer program or Turing machine that will always provide the correct answer. Any program would occasionally give a wrong answer or run forever without giving any answer. Famous examples of undecidable problems are the halting problem, the Entscheidungsproblem, and the unsolvability of the Diophantine equation. Conventionally, an undecidable problem is derived from a recursive set, formulated in undecidable language, and measured by the Turing degree. Undecidability, with respect to computer science and mathematical logic, is also called unsolvability or non-computability.
Undecidability and uncertainty are not one and the same phenomenon. Mathematical theorems which can be formally proved, will, according to mathematical fallibilists, nevertheless remain inconclusive. Take for example proof of the independence of the continuum hypothesis or, even more fundamentally, proof of the diagonal argument. In the end, both types of undecidability add further nuance to fallibilism, by providing these fundamental thought-experiments.
Philosophical skepticism
Fallibilism should not be confused with local or global skepticism, which is the view that some or all types of knowledge are unattainable.
But the fallibility of our knowledge — or the thesis that all knowledge is guesswork, though some consists of guesses which have been most severely tested — must not be cited in support of scepticism or relativism. From the fact that we can err, and that a criterion of truth which might save us from error does not exist, it does not follow that the choice between theories is arbitrary, or non-rational: that we cannot learn, or get nearer to the truth: that our knowledge cannot grow.
— Karl Popper
Fallibilism claims that legitimate epistemic justifications can lead to false beliefs, whereas academic skepticism claims that no legitimate epistemic justifications exist (acatalepsy). Fallibilism is also different to epoché, a suspension of judgement, often accredited to Pyrrhonian skepticism.
Criticism
Nearly all philosophers today are fallibilists in some sense of the term. Few would claim that knowledge requires absolute certainty, or deny that scientific claims are revisable, though in the 21st century some philosophers have argued for some version of infallibilist knowledge. Historically, many Western philosophers from Plato to Saint Augustine to René Descartes have argued that some human beliefs are infallibly known. John Calvin espoused a theological fallibilism towards others beliefs. Plausible candidates for infallible beliefs include logical truths ("Either Jones is a Democrat or Jones is not a Democrat"), immediate appearances ("It seems that I see a patch of blue"), and incorrigible beliefs (i.e., beliefs that are true in virtue of being believed, such as Descartes' "I think, therefore I am"). Many others, however, have taken even these types of beliefs to be fallible.
See also
- Defeasible reasoning
- Logical holism
- Nihilism
- Multiverse (set theory)
- Pancritical rationalism
- Perspectivism
- Pragmatism § Reconciliation of anti-skepticism and fallibilism
- Probabilism
- Projectivism
References
- Peirce, Charles S. (1896–1899) "The Scientific Attitude and Fallibilism". In Buchler, Justus (1940). Philosophical Writings of Peirce. Routledge. p. 59.
- Haack, Susan (1979). "Fallibilism and Necessity". Synthese, Vol. 41, No. 1, pp. 37–63.
- Hetherington, Stephen. "Fallibilism". Internet Encyclopedia of Philosophy.
- Anastas, Jeane W. (1999). Research Design for Social Work and the Human Services. Columbia University Press. p. 19.
- Levi, Isaac (1984). Messianic vs Myopic Realism. The University of Chicago Press. Vol. 2. pp. 617–636.
- Aikin, Scott F. (2014). "Prospects for Moral Epistemic Infinitism". Metaphilosophy. Vol. 45. No. 2. pp. 172–181.
- Annas, Julia & Barnes, Jonathan (2000). Sextus Empiricus: Outlines of Scepticism. Cambridge University Press.
- Hobbes, Thomas (1974). De homine. Cambridge University Press. Vol. 20.
- Rorty, Amélie; Schmidt, James (2009). Kant's Idea for a Universal History with a Cosmopolitan Aim. Cambridge University Press.
- Aristotle (350 B.C.E.). Physics. Massachusetts Institute of Technology.
- Cooke, Elizabeth F. (2006). Peirce's Pragmatic Theory of Inquiry: Fallibilism and Indeterminacy. Continuum.
- Kuhn, Thomas S. (1962). The Structure of Scientific Revolutions. University of Chicago Press.
- Thornton, Stephen (2022). Karl Popper. Stanford Encyclopedia of Philosophy.
- Forrai, Gábor (2002). Lakatos, Reason and History. p. 6–7. In Kampis, George; Kvasz, Ladislav & Stöltzner, Michael (2002). Appraising Lakatos: Mathematics, Methodology, and the Man. Vienna Circle Institute Library. Vol. 1.
- Zahar, E. G. (1983). The Popper-Lakatos Controversy in the Light of 'Die Beiden Grundprobleme Der Erkenntnistheorie'. The British Journal for the Philosophy of Science. p. 149–171.
- Musgrave, Alan; Pigden, Charles (2021). "Imre Lakatos". Stanford Encyclopedia of Philosophy.
- Kiss, Ogla (2006). Heuristic, Methodology or Logic of Discovery? Lakatos on Patterns of Thinking. MIT Press Direct. p. 314.
- Lakatos, Imre (1978). Mathematics, Science and Epistemology. Cambridge University Press. Vol. 2. p. 9–23.
- Popper, Karl (1995). The Myth of the Framework: In Defence of Science and Rationality. Routledge. p. 16.
- Kockelmans, Joseph J. Reflections on Lakatos’ Methodology of Scientific Research Programs. Boston Studies in the Philosophy of Science. Vol. 59. pp. 187–203. In Radnitzky, Gerard & Andersson, Gunnar. The Structure and Development of Science. D. Reidel Publishing Company.
- Quine, Willard. V. O. (1951). "Two Dogmas of Empiricism". The Philosophical Review Vol. 60, No. 1, pp. 20–43.
- Haack, Susan (1978). Philosophy of Logics. Cambridge University Press. pp. 234; Chapter 12.
- Niemann, Hans-Joachim (2000). Hans Albert - critical rationalist. Opensociety.
- Lakatos, Imre (1962). "Infinite Regress and Foundations of Mathematics (in Symposium: The Foundations of Mathematics)". Proceedings of the Aristotelian Society, Supplementary Volumes. 36: 145–184 (165). JSTOR 4106691.
Popperian critical fallibilism takes the infinite regress in proofs and definitions seriously, does not have illusions about 'stopping' them, accepts the sceptic criticism of any infallible truth-injection.
However, Lakatos' interpretation of Popper was not equivalent to Popper's philosophy: Ravn, Ole; Skovsmose, Ole (2019). "Mathematics as Dialogue". Connecting Humans to Equations: A Reinterpretation of the Philosophy of Mathematics. History of Mathematics Education. Cham: Springer-Verlag. pp. 107–119 (110). doi:10.1007/978-3-030-01337-0_8. ISBN 9783030013363. S2CID 127561458.Lakatos also refers to the scepticist programme as a 'Popperian critical fallibilism.' However, we find that this labelling could be a bit misleading as the programme includes a good deal of Lakatos' own philosophy.
- Kadvany, John (2001). Imre Lakatos and the Guises of Reason. Duke University Press. pp. 45, 109, 155, 323.
- Falguera, José L.; Rivas, Uxía; Sagüillo, José M. (1999). Analytic Philosophy at the Turn of the Millennium: Proceedings of the International Congress: Santiago de Compostela, 1–4 December, 1999. Servicio de Publicacións da Universidade de Santiago de Compostela. pp. 259–261.
- Dove, Ian J. (2004). Certainty and error in mathematics: Deductivism and the claims of mathematical fallibilism. Dissertation, Rice University. pp. 120-122.
- Gödel, Kurt (1940). The Consistency of the Continuum-Hypothesis. Princeton University Press. Vol. 3.
- Enderton, Herbert. "Continuum hypothesis". Encyclopædia Britannica.
- Cohen, Paul (1963). "The Independence of the Continuum Hypothesis". Proceedings of the National Academy of Sciences of the United States of America. Vol. 50, No. 6. pp. 1143–1148.
- Goodman, Nicolas D. (1979) "Mathematics as an Objective Science". The American Mathematical Monthly. Vol. 86, No. 7. pp. 540-551.
- Cantor, Georg (1877). "Ein Beitrag zur Mannigfaltigkeitslehre". Journal für die reine und angewandte Mathematik. Vol. 84. pp. 242-258.
- Hosch, William L. "Cantor's theorem". Encyclopædia Britannica.
- Forster, Thomas. E. (1992). Set Theory with a Universal Set: Exploring an Untyped Universe. Clarendon Press.
- Goodman, Nicolas D. (1979) "Mathematics as an Objective Science". The American Mathematical Monthly. Vol. 86, No. 7. pp. 540-551.
- Marciszewskip, Witold (2015). "On accelerations in science driven by daring ideas: Good messages from fallibilistic rationalism". Studies in Logic, Grammar and Rhetoric 40, no. 1. p. 39.
- Rogers, Hartley (1971). "Theory of Recursive Functions and Effective Computability". Journal of Symbolic Logic. Vol. 36. pp. 141–146.
- Post, Emil L. (1944). Recursively enumerable sets of positive integers and their decision problems. Bulletin of the American Mathematical Society.
- Kleene, Stephen C.; Post, Emil L. (1954). "The upper semi-lattice of degrees of recursive unsolvability". Annals of Mathematics. Vol. 59. No. 3. pp. 379–407.
- Dove, Ian J. (2004). Certainty and error in mathematics: Deductivism and the claims of mathematical fallibilism. Dissertation, Rice University. pp. 120-122.
- Lakatos, Imre; Worrall, John & Zahar, Elie (1976). "Proofs and Refutations". Cambridge University Press. p. 9.
- Moon, Andrew (2012). "Warrant does entail truth". Synthese. Vol. 184. No. 3. pp. 287–297.
- Dutant, Julien (2016). "How to be an infallibilist". Philosophical Issues. Vol 26. pp. 148–171.
- Benton, Matthew (2021). "Knowledge, hope, and fallibilism". Synthese. Vol. 198. pp. 1673–1689.
- Friedman, J. (2022). Intolerance: Premodern Roots and Modern Manifestations. Taylor & Francis. p. 12. ISBN 978-1-000-80294-8. Retrieved 2023-06-01.
- Helm, P. (2010). Calvin at the Centre. OUP Oxford. p. 92. ISBN 978-0-19-953218-6. Retrieved 2023-06-01.
Further reading
- Charles S. Peirce: Selected Writings, by Philip P. Wiener (Dover, 1980)
- Charles S. Peirce and the Philosophy of Science, by Edward C. Moore (Alabama, 1993)
- Treatise on Critical Reason, by Hans Albert (Tübingen, 1968; English translation, Princeton, 1985)
External links
- Epistemic Fallibilism at PhilPapers
- "Fallibilism" by Stephen Hetherington in the Internet Encyclopedia of Philosophy
- "Fallibilism"
by Nicholas Rescher in the Routledge Encyclopedia of Philosophy
Originally fallibilism from Medieval Latin fallibilis liable to error is the philosophical principle that propositions can be accepted even though they cannot be conclusively proven or justified or that neither knowledge nor belief is certain The term was coined in the late nineteenth century by the American philosopher Charles Sanders Peirce as a response to foundationalism Theorists following Austrian British philosopher Karl Popper may also refer to fallibilism as the notion that knowledge might turn out to be false Furthermore fallibilism is said to imply corrigibilism the principle that propositions are open to revision Fallibilism is often juxtaposed with infallibilism Charles Sanders Peirce around 1900 Peirce is said to have initiated fallibilism Infinite regress and infinite progressAccording to philosopher Scott F Aikin fallibilism cannot properly function in the absence of infinite regress The term usually attributed to Pyrrhonist philosopher Agrippa is argued to be the inevitable outcome of all human inquiry since every proposition requires justification Infinite regress also represented within the regress argument is closely related to the problem of the criterion and is a constituent of the Munchhausen trilemma Illustrious examples regarding infinite regress are the cosmological argument turtles all the way down and the simulation hypothesis Many philosophers struggle with the metaphysical implications that come along with infinite regress For this reason philosophers have gotten creative in their quest to circumvent it Somewhere along the seventeenth century English philosopher Thomas Hobbes set forth the concept of infinite progress With this term Hobbes had captured the human proclivity to strive for perfection Philosophers like Gottfried Wilhelm Leibniz Christian Wolff and Immanuel Kant would elaborate further on the concept Kant even went on to speculate that immortal species should hypothetically be able to develop their capacities to perfection Already in 350 B C E Greek philosopher Aristotle made a distinction between potential and actual infinities Based on his discourse it can be said that actual infinities do not exist because they are paradoxical Aristotle deemed it impossible for humans to keep on adding members to finite sets indefinitely It eventually led him to refute some of Zeno s paradoxes Other relevant examples of potential infinities include Galileo s paradox and the paradox of Hilbert s hotel The notion that infinite regress and infinite progress only manifest themselves potentially pertains to fallibilism According to philosophy professor Elizabeth F Cooke fallibilism embraces uncertainty and infinite regress and infinite progress are not unfortunate limitations on human cognition but rather necessary antecedents for knowledge acquisition They allow us to live functional and meaningful lives Critical rationalismThe founder of critical rationalism Karl Popper In the mid twentieth century several important philosophers began to critique the foundations of logical positivism In his work The Logic of Scientific Discovery 1934 Karl Popper the founder of critical rationalism argued that scientific knowledge grows from falsifying conjectures rather than any inductive principle and that falsifiability is the criterion of a scientific proposition The claim that all assertions are provisional and thus open to revision in light of new evidence is widely taken for granted in the natural sciences Furthermore Popper defended his critical rationalism as a normative and methodological theory that explains how objective and thus mind independent knowledge ought to work Hungarian philosopher Imre Lakatos built upon the theory by rephrasing the problem of demarcation as the problem of normative appraisal Lakatos and Popper s aims were alike that is finding rules that could justify falsifications However Lakatos pointed out that critical rationalism only shows how theories can be falsified but it omits how our belief in critical rationalism can itself be justified The belief would require an inductively verified principle When Lakatos urged Popper to admit that the falsification principle cannot be justified without embracing induction Popper did not succumb Lakatos critical attitude towards rationalism has become emblematic for his so called critical fallibilism While critical fallibilism strictly opposes dogmatism critical rationalism is said to require a limited amount of dogmatism Though even Lakatos himself had been a critical rationalist in the past when he took it upon himself to argue against the inductivist illusion that axioms can be justified by the truth of their consequences In summary despite Lakatos and Popper picking one stance over the other both have oscillated between holding a critical attitude towards rationalism as well as fallibilism Fallibilism has also been employed by philosopher Willard V O Quine to attack among other things the distinction between analytic and synthetic statements British philosopher Susan Haack following Quine has argued that the nature of fallibilism is often misunderstood because people tend to confuse fallible propositions with fallible agents She claims that logic is revisable which means that analyticity does not exist and necessity or a priority does not extend to logical truths She hereby opposes the conviction that propositions in logic are infallible while agents can be fallible Critical rationalist Hans Albert argues that it is impossible to prove any truth with certainty not only in logic but also in mathematics Mathematical fallibilismImre Lakatos in the 1960s known for his contributions to mathematical fallibilism In Proofs and Refutations The Logic of Mathematical Discovery 1976 philosopher Imre Lakatos implemented mathematical proofs into what he called Popperian critical fallibilism Lakatos s mathematical fallibilism is the general view that all mathematical theorems are falsifiable Mathematical fallibilism deviates from traditional views held by philosophers like Hegel Peirce and Popper Although Peirce introduced fallibilism he seems to preclude the possibility of us being mistaken in our mathematical beliefs Mathematical fallibilism appears to uphold that even though a mathematical conjecture cannot be proven true we may consider some to be good approximations or estimations of the truth This so called verisimilitude may provide us with consistency amidst an inherent incompleteness in mathematics Mathematical fallibilism differs from quasi empiricism to the extent that the latter does not incorporate inductivism a feature considered to be of vital importance to the foundations of set theory In the philosophy of mathematics a central tenet of fallibilism is undecidability which bears resemblance to the notion of isostheneia or equal veracity Two distinct types of the word undecidable are currently being applied The first one relates most notably to the continuum hypothesis which was proposed by mathematician Georg Cantor in 1873 The continuum hypothesis represents a tendency for infinite sets to allow for undecidable solutions solutions which are true in one constructible universe and false in another Both solutions are independent from the axioms in Zermelo Fraenkel set theory combined with the axiom of choice also called ZFC This phenomenon has been labeled the independence of the continuum hypothesis Both the hypothesis and its negation are thought to be consistent with the axioms of ZFC Many noteworthy discoveries have preceded the establishment of the continuum hypothesis In 1877 Cantor introduced the diagonal argument to prove that the cardinality of two finite sets is equal by putting them into a one to one correspondence Diagonalization reappeared in Cantors theorem in 1891 to show that the power set of any countable set must have strictly higher cardinality The existence of the power set was postulated in the axiom of power set a vital part of Zermelo Fraenkel set theory Moreover in 1899 Cantor s paradox was discovered It postulates that there is no set of all cardinalities Two years later polymath Bertrand Russell would invalidate the existence of the universal set by pointing towards Russell s paradox which implies that no set can contain itself as an element or member The universal set can be confuted by utilizing either the axiom schema of separation or the axiom of regularity In contrast to the universal set a power set does not contain itself It was only after 1940 that mathematician Kurt Godel showed by applying inter alia the diagonal lemma that the continuum hypothesis cannot be refuted and after 1963 that fellow mathematician Paul Cohen revealed through the method of forcing that the continuum hypothesis cannot be proved either In spite of the undecidability both Godel and Cohen suspected dependence of the continuum hypothesis to be false This sense of suspicion in conjunction with a firm belief in the consistency of ZFC is in line with mathematical fallibilism Mathematical fallibilists suppose that new axioms for example the axiom of projective determinacy might improve ZFC but that these axioms will not allow for dependence of the continuum hypothesis The second type of undecidability is used in relation to computability theory or recursion theory and applies not solely to statements but specifically to decision problems mathematical questions of decidability An undecidable problem is a type of computational problem in which there are countably infinite sets of questions each requiring an effective method to determine whether an output is either yes or no or whether a statement is either true or false but where there cannot be any computer program or Turing machine that will always provide the correct answer Any program would occasionally give a wrong answer or run forever without giving any answer Famous examples of undecidable problems are the halting problem the Entscheidungsproblem and the unsolvability of the Diophantine equation Conventionally an undecidable problem is derived from a recursive set formulated in undecidable language and measured by the Turing degree Undecidability with respect to computer science and mathematical logic is also called unsolvability or non computability Undecidability and uncertainty are not one and the same phenomenon Mathematical theorems which can be formally proved will according to mathematical fallibilists nevertheless remain inconclusive Take for example proof of the independence of the continuum hypothesis or even more fundamentally proof of the diagonal argument In the end both types of undecidability add further nuance to fallibilism by providing these fundamental thought experiments Philosophical skepticismFallibilism should not be confused with local or global skepticism which is the view that some or all types of knowledge are unattainable But the fallibility of our knowledge or the thesis that all knowledge is guesswork though some consists of guesses which have been most severely tested must not be cited in support of scepticism or relativism From the fact that we can err and that a criterion of truth which might save us from error does not exist it does not follow that the choice between theories is arbitrary or non rational that we cannot learn or get nearer to the truth that our knowledge cannot grow Karl Popper Fallibilism claims that legitimate epistemic justifications can lead to false beliefs whereas academic skepticism claims that no legitimate epistemic justifications exist acatalepsy Fallibilism is also different to epoche a suspension of judgement often accredited to Pyrrhonian skepticism CriticismNearly all philosophers today are fallibilists in some sense of the term Few would claim that knowledge requires absolute certainty or deny that scientific claims are revisable though in the 21st century some philosophers have argued for some version of infallibilist knowledge Historically many Western philosophers from Plato to Saint Augustine to Rene Descartes have argued that some human beliefs are infallibly known John Calvin espoused a theological fallibilism towards others beliefs Plausible candidates for infallible beliefs include logical truths Either Jones is a Democrat or Jones is not a Democrat immediate appearances It seems that I see a patch of blue and incorrigible beliefs i e beliefs that are true in virtue of being believed such as Descartes I think therefore I am Many others however have taken even these types of beliefs to be fallible See alsoDefeasible reasoning Logical holism Nihilism Multiverse set theory Pancritical rationalism Perspectivism Pragmatism Reconciliation of anti skepticism and fallibilism Probabilism ProjectivismReferencesPeirce Charles S 1896 1899 The Scientific Attitude and Fallibilism In Buchler Justus 1940 Philosophical Writings of Peirce Routledge p 59 Haack Susan 1979 Fallibilism and Necessity Synthese Vol 41 No 1 pp 37 63 Hetherington Stephen Fallibilism Internet Encyclopedia of Philosophy Anastas Jeane W 1999 Research Design for Social Work and the Human Services Columbia University Press p 19 Levi Isaac 1984 Messianic vs Myopic Realism The University of Chicago Press Vol 2 pp 617 636 Aikin Scott F 2014 Prospects for Moral Epistemic Infinitism Metaphilosophy Vol 45 No 2 pp 172 181 Annas Julia amp Barnes Jonathan 2000 Sextus Empiricus Outlines of Scepticism Cambridge University Press Hobbes Thomas 1974 De homine Cambridge University Press Vol 20 Rorty Amelie Schmidt James 2009 Kant s Idea for a Universal History with a Cosmopolitan Aim Cambridge University Press Aristotle 350 B C E Physics Massachusetts Institute of Technology Cooke Elizabeth F 2006 Peirce s Pragmatic Theory of Inquiry Fallibilism and Indeterminacy Continuum Kuhn Thomas S 1962 The Structure of Scientific Revolutions University of Chicago Press Thornton Stephen 2022 Karl Popper Stanford Encyclopedia of Philosophy Forrai Gabor 2002 Lakatos Reason and History p 6 7 In Kampis George Kvasz Ladislav amp Stoltzner Michael 2002 Appraising Lakatos Mathematics Methodology and the Man Vienna Circle Institute Library Vol 1 Zahar E G 1983 The Popper Lakatos Controversy in the Light of Die Beiden Grundprobleme Der Erkenntnistheorie The British Journal for the Philosophy of Science p 149 171 Musgrave Alan Pigden Charles 2021 Imre Lakatos Stanford Encyclopedia of Philosophy Kiss Ogla 2006 Heuristic Methodology or Logic of Discovery Lakatos on Patterns of Thinking MIT Press Direct p 314 Lakatos Imre 1978 Mathematics Science and Epistemology Cambridge University Press Vol 2 p 9 23 Popper Karl 1995 The Myth of the Framework In Defence of Science and Rationality Routledge p 16 Kockelmans Joseph J Reflections on Lakatos Methodology of Scientific Research Programs Boston Studies in the Philosophy of Science Vol 59 pp 187 203 In Radnitzky Gerard amp Andersson Gunnar The Structure and Development of Science D Reidel Publishing Company Quine Willard V O 1951 Two Dogmas of Empiricism The Philosophical Review Vol 60 No 1 pp 20 43 Haack Susan 1978 Philosophy of Logics Cambridge University Press pp 234 Chapter 12 Niemann Hans Joachim 2000 Hans Albert critical rationalist Opensociety Lakatos Imre 1962 Infinite Regress and Foundations of Mathematics in Symposium The Foundations of Mathematics Proceedings of the Aristotelian Society Supplementary Volumes 36 145 184 165 JSTOR 4106691 Popperian critical fallibilism takes the infinite regress in proofs and definitions seriously does not have illusions about stopping them accepts the sceptic criticism of any infallible truth injection However Lakatos interpretation of Popper was not equivalent to Popper s philosophy Ravn Ole Skovsmose Ole 2019 Mathematics as Dialogue Connecting Humans to Equations A Reinterpretation of the Philosophy of Mathematics History of Mathematics Education Cham Springer Verlag pp 107 119 110 doi 10 1007 978 3 030 01337 0 8 ISBN 9783030013363 S2CID 127561458 Lakatos also refers to the scepticist programme as a Popperian critical fallibilism However we find that this labelling could be a bit misleading as the programme includes a good deal of Lakatos own philosophy Kadvany John 2001 Imre Lakatos and the Guises of Reason Duke University Press pp 45 109 155 323 Falguera Jose L Rivas Uxia Saguillo Jose M 1999 Analytic Philosophy at the Turn of the Millennium Proceedings of the International Congress Santiago de Compostela 1 4 December 1999 Servicio de Publicacions da Universidade de Santiago de Compostela pp 259 261 Dove Ian J 2004 Certainty and error in mathematics Deductivism and the claims of mathematical fallibilism Dissertation Rice University pp 120 122 Godel Kurt 1940 The Consistency of the Continuum Hypothesis Princeton University Press Vol 3 Enderton Herbert Continuum hypothesis Encyclopaedia Britannica Cohen Paul 1963 The Independence of the Continuum Hypothesis Proceedings of the National Academy of Sciences of the United States of America Vol 50 No 6 pp 1143 1148 Goodman Nicolas D 1979 Mathematics as an Objective Science The American Mathematical Monthly Vol 86 No 7 pp 540 551 Cantor Georg 1877 Ein Beitrag zur Mannigfaltigkeitslehre Journal fur die reine und angewandte Mathematik Vol 84 pp 242 258 Hosch William L Cantor s theorem Encyclopaedia Britannica Forster Thomas E 1992 Set Theory with a Universal Set Exploring an Untyped Universe Clarendon Press Goodman Nicolas D 1979 Mathematics as an Objective Science The American Mathematical Monthly Vol 86 No 7 pp 540 551 Marciszewskip Witold 2015 On accelerations in science driven by daring ideas Good messages from fallibilistic rationalism Studies in Logic Grammar and Rhetoric 40 no 1 p 39 Rogers Hartley 1971 Theory of Recursive Functions and Effective Computability Journal of Symbolic Logic Vol 36 pp 141 146 Post Emil L 1944 Recursively enumerable sets of positive integers and their decision problems Bulletin of the American Mathematical Society Kleene Stephen C Post Emil L 1954 The upper semi lattice of degrees of recursive unsolvability Annals of Mathematics Vol 59 No 3 pp 379 407 Dove Ian J 2004 Certainty and error in mathematics Deductivism and the claims of mathematical fallibilism Dissertation Rice University pp 120 122 Lakatos Imre Worrall John amp Zahar Elie 1976 Proofs and Refutations Cambridge University Press p 9 Moon Andrew 2012 Warrant does entail truth Synthese Vol 184 No 3 pp 287 297 Dutant Julien 2016 How to be an infallibilist Philosophical Issues Vol 26 pp 148 171 Benton Matthew 2021 Knowledge hope and fallibilism Synthese Vol 198 pp 1673 1689 Friedman J 2022 Intolerance Premodern Roots and Modern Manifestations Taylor amp Francis p 12 ISBN 978 1 000 80294 8 Retrieved 2023 06 01 Helm P 2010 Calvin at the Centre OUP Oxford p 92 ISBN 978 0 19 953218 6 Retrieved 2023 06 01 Further readingCharles S Peirce Selected Writings by Philip P Wiener Dover 1980 Charles S Peirce and the Philosophy of Science by Edward C Moore Alabama 1993 Treatise on Critical Reason by Hans Albert Tubingen 1968 English translation Princeton 1985 External linksEpistemic Fallibilism at PhilPapers Fallibilism by Stephen Hetherington in the Internet Encyclopedia of Philosophy Fallibilism by Nicholas Rescher in the Routledge Encyclopedia of Philosophy