Critical rationalism is an
epistemological
Epistemology is the branch of philosophy that examines the nature, origin, and limits of knowledge. Also called "the theory of knowledge", it explores different types of knowledge, such as propositional knowledge about facts, practical knowled ...
philosophy
Philosophy ('love of wisdom' in Ancient Greek) is a systematic study of general and fundamental questions concerning topics like existence, reason, knowledge, Value (ethics and social sciences), value, mind, and language. It is a rational an ...
advanced by
Karl Popper
Sir Karl Raimund Popper (28 July 1902 – 17 September 1994) was an Austrian–British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the ...
on the basis that, if a statement cannot be logically deduced (from what is known), it might nevertheless be possible to logically falsify it. Following
Hume, Popper rejected any
inductive logic
Inductive reasoning refers to a variety of methods of reasoning in which the conclusion of an argument is supported not with deductive certainty, but with some degree of probability. Unlike ''deductive'' reasoning (such as mathematical inducti ...
that is
ampliative Ampliative (from Latin ''ampliare'', "to enlarge"), a term used mainly in logic, meaning "extending" or "adding to that which is already known".
This terminology was often used by medieval logicians in the analyses of the temporal content of the ...
, i.e., any logic that can provide more knowledge than deductive logic. This led Popper to his
falsifiability criterion.
Popper wrote about critical rationalism in many works, including: ''
The Logic of Scientific Discovery
''The Logic of Scientific Discovery'' is a 1959 book about the philosophy of science by the philosopher Karl Popper. Popper rewrote his book in English from the 1934 (imprint '1935') German original, titled ''Logik der Forschung. Zur Erkenntnisth ...
'' (1934/1959), ''
The Open Society and Its Enemies'' (1945), ''
Conjectures and Refutations'' (1963), ''
Unended Quest'' (1976), and ''
The Myth of the Framework'' (1994).
Criticism, not support
Critical rationalists hold that scientific
theories
A theory is a systematic and rational form of abstract thinking about a phenomenon, or the conclusions derived from such thinking. It involves contemplative and logical reasoning, often supported by processes such as observation, experimentation, ...
and any other claims to
knowledge
Knowledge is an Declarative knowledge, awareness of facts, a Knowledge by acquaintance, familiarity with individuals and situations, or a Procedural knowledge, practical skill. Knowledge of facts, also called propositional knowledge, is oft ...
can and should be rationally criticized, and (if they have
empirical
Empirical evidence is evidence obtained through sense experience or experimental procedure. It is of central importance to the sciences and plays a role in various other fields, like epistemology and law.
There is no general agreement on how t ...
content) can and should be subjected to tests which may falsify them. Thus claims to knowledge may be contrastingly and normatively evaluated. They are either falsifiable and thus empirical (in a very broad sense), or not falsifiable and thus non-empirical. Those claims to knowledge that are potentially falsifiable can then be admitted to the body of empirical science, and then further differentiated according to whether they are retained or are later actually falsified. If retained, further differentiation may be made on the basis of how much subjection to criticism they have received, how severe such criticism has been, and how probable the theory is, with the ''least'' probable theory that still withstands attempts to falsify it being the one to be preferred.
[, section 43, especially footnote *1 and *2] That it is the ''least'' probable theory that is to be preferred is one of the contrasting differences between critical rationalism and classical views on science, such as positivism, which holds that one should instead accept the ''most'' probable theory.
[ The least probable theory is preferred because it is the one with the highest information content and most open to future falsification.
Critical rationalism as a discourse positioned itself against what its proponents took to be epistemologically relativist philosophies, particularly ]post-modernist
Postmodernism encompasses a variety of artistic, cultural, and philosophical movements that claim to mark a break from modernism. They have in common the conviction that it is no longer possible to rely upon previous ways of depicting the worl ...
or sociological
Sociology is the scientific study of human society that focuses on society, human social behavior, patterns of social relationships, social interaction, and aspects of culture associated with everyday life. The term sociology was coined in ...
approaches to knowledge. Critical rationalism holds that knowledge is objective (in the sense of being embodied in various substrates and in the sense of not being reducible to what humans individually "know"), and also that truth is objective (exists independently of social mediation or individual perception, but is "really real").
However, this contrastive, critical approach to objective knowledge is quite different from more traditional views that also hold knowledge to be objective. (These include the classical rationalism of the Enlightenment, the verificationism
Verificationism, also known as the verification principle or the verifiability criterion of meaning, is a doctrine in philosophy which asserts that a statement is meaningful only if it is either empirically verifiable (can be confirmed through the ...
of the logical positivists
Logical positivism, also known as logical empiricism or neo-positivism, was a philosophical movement, in the empiricist tradition, that sought to formulate a scientific philosophy in which philosophical discourse would be, in the perception of ...
, or approaches to science based on induction, a supposed form of logical inference which critical rationalists reject, in line with David Hume
David Hume (; born David Home; – 25 August 1776) was a Scottish philosopher, historian, economist, and essayist who was best known for his highly influential system of empiricism, philosophical scepticism and metaphysical naturalism. Beg ...
.) For criticism is all that can be done when attempting to differentiate claims to knowledge, according to the critical rationalist. Reason is the organon
The ''Organon'' (, meaning "instrument, tool, organ") is the standard collection of Aristotle's six works on logical analysis and dialectic. The name ''Organon'' was given by Aristotle's followers, the Peripatetics, who maintained against the ...
of criticism, not of support; of tentative refutation, not of proof.
Supposed positive evidence (such as the provision of "good reasons" for a claim, or its having been "corroborated" by making successful predictions) does nothing to bolster, support, or prove a claim, belief, or theory.
In this sense, critical rationalism turns the normal understanding of a traditional rationalist, and a realist, on its head. Especially the view that a theory is better if it is less likely to be true is in direct opposition to the traditional positivistic view, which holds that one should seek theories that have a high probability.[ Popper notes that this "may illustrate Schopenhauer's remark that the solution of a problem often first looks like a paradox and later like a truism". Even a highly unlikely theory that conflicts with a current observation (and is thus false, like "all swans are white") must be considered to be better than one which fits observations perfectly, but is highly probable (like "all swans have a color"). This insight is the crucial difference between naive falsificationism and critical rationalism. The lower probability theory is favoured by critical rationalism because the greater the informative content of a theory the lower will be its probability, for the more information a statement contains, the greater will be the number of ways in which it may turn out to be false. The rationale behind this is simply to make it as easy as possible to find out whether the theory is false so that it can be replaced by one that is closer to the truth. It is not meant as a concession to justificatory epistemology, like assuming a theory to be "justifiable" by asserting that it is highly unlikely and yet fits observation.
Critical rationalism rejects the classical position that knowledge is justified true belief; it instead holds the exact opposite: that, in general, knowledge is unjustified untrue unbelief. It is unjustified because of the non-existence of good reasons. It is untrue, because it usually contains errors that sometimes remain unnoticed for hundreds of years. And it is not belief either, because scientific knowledge, or the knowledge needed to, for example, build an airplane, is contained in no single person's mind. It is only what is recorded in artifacts such as books.
]
Non-justificationism
William Warren Bartley
William Warren Bartley III (October 2, 1934 – February 5, 1990), known as W. W. Bartley III, was an American philosopher specializing in 20th century philosophy, language and logic, and the Vienna Circle.
Early life and education
Born in ...
compared critical rationalism to the very general philosophical approach to knowledge which he called justificationism, the view that scientific theories can be justified. Most justificationists do not know that they are justificationists. Justificationism is what Popper called a "subjectivist" view of truth, in which the question of whether some statement is true is confused with the question of whether it can be justified (established, proven, verified, warranted, made well-founded, made reliable, grounded, supported, legitimated, based on evidence) in some way.
According to Bartley, some justificationists are positive about this mistake. They are naïve rationalists, and thinking that their knowledge can indeed be founded, in principle, it may be deemed certain to some degree, and rational.
Other justificationists are negative about these mistakes. They are epistemological relativists, and think (rightly, according to the critical rationalist) that you cannot ''find'' knowledge, that there is no source of epistemological absolutism. But they conclude (wrongly, according to the critical rationalist) that there is therefore no rationality, and no objective distinction to be made between the true and the false.
By dissolving justificationism itself, the critical rationalist (a proponent of non-justificationism) regards knowledge and rationality, reason and science, as neither foundational nor infallible, but nevertheless does not think we must therefore all be relativists. Knowledge and truth still exist, just not in the way we thought.
Non-justificationism is also accepted by David Miller and Karl Popper
Sir Karl Raimund Popper (28 July 1902 – 17 September 1994) was an Austrian–British philosopher, academic and social commentator. One of the 20th century's most influential philosophers of science, Popper is known for his rejection of the ...
. However, not all proponents of critical rationalism oppose justificationism; it is supported most prominently by John W. N. Watkins. In justificationism, criticism consists of trying to show that a claim cannot be reduced to the authority or criteria that it appeals to. That is, it regards the justification of a claim as primary, while the claim itself is secondary. By contrast, non-justificational criticism works towards attacking claims themselves.
The pitfalls of justificationism and positivism
The rejection of "positivist" approaches to knowledge occurs due to various pitfalls that positivism falls into.
# The naïve empiricism
In philosophy, empiricism is an epistemological view which holds that true knowledge or justification comes only or primarily from sensory experience and empirical evidence. It is one of several competing views within epistemology, along ...
of induction was shown to be illogical by Hume. A thousand observations of some event A coinciding with some event B does not allow one to logically infer that all A events coincide with B events. According to the critical rationalist, if there is a sense in which humans accrue knowledge positively by experience, it is only by pivoting observations off existing conjectural theories pertinent to the observations, or off underlying cognitive schemas which unconsciously handle perceptions and use them to generate new theories. But these new theories advanced in response to perceived particulars are not ''logically'' "induced" from them. These new theories may be wrong. The myth that we ''induce'' theories from particulars is persistent because ''when'' we do this we are often successful, but this is due to the advanced state of our evolved tendencies. If we were really "inducting" theories from particulars, it would be inductively logical to claim that the sun sets ''because'' I get up in the morning, or that all buses must have drivers in them (if you've never seen an empty bus).
# Popper and David Miller showed in 1983 that evidence supposed to partly support a hypothesis can, in fact, only be neutral to, or even be counter-supportive of the hypothesis.
# Related to the point above, David Miller, attacks the use of "good reasons" in general (including evidence supposed to support the excess content of a hypothesis). He argues that good reasons are neither attainable, nor even desirable. Basically, Miller asserts that all arguments purporting to give valid support for a claim are either circular or question-begging. That is, if one provides a valid deductive argument (an inference from premises to a conclusion) for a given claim, then the content of the claim must already be contained within the premises of the argument (if it is not, then the argument is ampliative Ampliative (from Latin ''ampliare'', "to enlarge"), a term used mainly in logic, meaning "extending" or "adding to that which is already known".
This terminology was often used by medieval logicians in the analyses of the temporal content of the ...
and so is invalid). Therefore, the claim is already presupposed by the premises, and is no more "supported" than are the assumptions upon which the claim rests, i.e. begging the question.
Variations
William Warren Bartley
William Warren Bartley III (October 2, 1934 – February 5, 1990), known as W. W. Bartley III, was an American philosopher specializing in 20th century philosophy, language and logic, and the Vienna Circle.
Early life and education
Born in ...
developed a variation of critical rationalism that he called pancritical rationalism.
Argentine-Canadian philosopher of science Mario Bunge
Mario Augusto Bunge ( ; ; September 21, 1919 – February 24, 2020) was an Argentine-Canadian philosopher and physicist. His philosophical writings combined scientific realism, systemism, materialism, emergentism, and other principles.
He was a ...
, who edited a book dedicated to Popper in 1964 that included a paper by Bartley, appreciated critical rationalism but found it insufficient as a comprehensive philosophy of science, so he built upon it (and many other ideas) to formulate his own account of scientific realism
Scientific realism is the philosophical view that the universe described by science (including both observable and unobservable aspects) exists independently of our perceptions, and that verified scientific theories are at least approximately true ...
in his many publications.[See, for example, among secondary sources:
*
*
* ]
See also
* Münchhausen trilemma
In epistemology, the Münchhausen trilemma is a thought experiment intended to demonstrate the theoretical impossibility of proving any truth, even in the fields of logic and mathematics, without appealing to accepted assumptions. If it is asked ...
* Positivism dispute
The positivism dispute () was a political-philosophical dispute between the Critical rationalism, critical rationalists (Karl Popper, Hans Albert) and the Frankfurt School (Theodor Adorno, Jürgen Habermas) in 1961, about the methodology of the so ...
People
* Hans Albert
Hans Albert (; 8 February 1921 24 October 2023) was a German philosopher. He was professor of social sciences at the University of Mannheim from 1963, and remained at the university until 1989. His fields of research were social sciences and g ...
* David Deutsch
David Elieser Deutsch ( ; ; born 18 May 1953) is a British physicist at the University of Oxford, often described as the "father of quantum computing". He is a visiting professor in the Department of Atomic and Laser Physics at the Centre for ...
* John Eccles
* Ernest Gellner
* Hans Adolf Krebs
* Reinhold Zippelius
References
Further reading
* Maxwell, Nicholas (2017
Karl Popper, Science and Enlightenment
UCL Press, London. Free online.
* Niemann, Hans-Joachim. ''Lexikon des Kritischen Rationalismus'', (Encyclopaedia of Critical Rationalism), Tübingen (Mohr Siebeck) 2004, . More than a thousand headwords about critical rationalism, the most important arguments of K.R. Popper and H. Albert, quotations of the original wording. Edition for students in 2006, .
* Parusniková, Zuzana & Robert S. Cohen (2009). ''Rethinking Popper''
Description
an
contents.
Springer.
* Reinhold Zippelius. ''Die experimentierende Methode im Recht'' (trial and error in jurisprudence), (Academy of Science, Mainz) 1991,
External links
Critical Rationalism: a personal account
Critical Rationalism Blog
Discusses critical rationalism from a libertarianist political point of view
*
{{Authority control
Rationalism
Epistemological theories
Epistemology of science
Karl Popper
Metatheory of science