Verificationism, also known as the verification principle or the verifiability criterion of meaning, is the philosophical doctrine that only statements that are empirically verifiable (i.e. verifiable through the senses) are cognitively meaningful, or else they are truths of logic (tautologies).
Philosophy is the study of general and fundamental questions about existence, knowledge, values, reason, mind, and language. Such questions are often posed as problems to be studied or resolved. The term was probably coined by Pythagoras. Philosophical methods include questioning, critical discussion, rational argument, and systematic presentation. Classic philosophical questions include: Is it possible to know anything and to prove it? What is most real? Philosophers also pose more practical and concrete questions such as: Is there a best way to live? Is it better to be just or unjust? Do humans have free will?
In philosophy, empiricism is a theory that states that knowledge comes only or primarily from sensory experience. It is one of several views of epistemology, the study of human knowledge, along with rationalism and skepticism. Empiricism emphasises the role of empirical evidence in the formation of ideas, rather than innate ideas or traditions. However, empiricists may argue that traditions arise due to relations of previous sense experiences.
A sense is a physiological capacity of organisms that provides data for perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology, and philosophy of perception. The nervous system has a specific sensory nervous system, and a sense organ, or sensor, dedicated to each sense.
Verificationism thus rejects as cognitively "meaningless" statements specific to entire fields such as metaphysics, spirituality, theology, ethics and aesthetics. Such statements may be meaningful in influencing emotions or behavior, but not in terms of truth value, information or factual content.Verificationism was a central thesis of logical positivism, a movement in analytic philosophy that emerged in the 1920s by the efforts of a group of philosophers who sought to unify philosophy and science under a common naturalistic theory of knowledge.
Metaphysics is the branch of philosophy that examines the fundamental nature of reality, including the relationship between mind and matter, between substance and attribute, and between possibility and actuality. The word "metaphysics" comes from two Greek words that, together, literally mean "after or behind or among [the study of] the natural". It has been suggested that the term might have been coined by a first century CE editor who assembled various small selections of Aristotle’s works into the treatise we now know by the name Metaphysics.
The meaning of spirituality has developed and expanded over time, and various connotations can be found alongside each other.
Theology is the critical study of the nature of the divine, and more broadly, of religious belief. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of analyzing the supernatural, but also especially with epistemology, and asks and seeks to answer the question of revelation. Revelation pertains to the acceptance of God, gods, or deities, as not only transcendent or above the natural world, but also willing and able to interact with the natural world and, in particular, to reveal themselves to humankind. While theology has turned into a secular field, religious adherents still consider theology to be a discipline that helps them live and understand concepts such as life and love and that helps them lead lives of obedience to the deities they follow or worship.
Although verificationist principles of a general sort—grounding scientific theory in some verifiable experience—are found retrospectively even with the American pragmatist C.S. Peirce and with the French conventionalist Pierre Duhemwho fostered instrumentalism, the vigorous program termed verificationism was launched by the logical positivists who, emerging from Berlin Circle and Vienna Circle in the 1920s, sought epistemology whereby philosophical discourse would be, in their perception, as authoritative and meaningful as empirical science.
Pragmatism is a philosophical tradition that began in the United States around 1870. Its origins are often attributed to the philosophers Charles Sanders Peirce, William James, and John Dewey. Peirce later described it in his pragmatic maxim: "Consider the practical effects of the objects of your conception. Then, your conception of those effects is the whole of your conception of the object."
Charles Sanders Peirce was an American philosopher, logician, mathematician, and scientist who is sometimes known as "the father of pragmatism". He was educated as a chemist and employed as a scientist for thirty years. Today he is appreciated largely for his contributions to logic, mathematics, philosophy, scientific methodology, semiotics, and for his founding of pragmatism.
Conventionalism is the philosophical attitude that fundamental principles of a certain kind are grounded on agreements in society, rather than on external reality. Although this attitude is commonly held with respect to the rules of grammar, its application to the propositions of ethics, law, science, mathematics, and logic is more controversial.
Logical positivists garnered the verifiability criterion of cognitive meaningfulness from young Ludwig Wittgenstein's philosophy of language posed in his 1921 book Tractatus ,and, led by Bertrand Russell, sought to reformulate the analytic–synthetic distinction in a way that would reduce mathematics and logic to semantical conventions. This would be pivotal to verificationism, in that logic and mathematics would otherwise be classified as synthetic a priori knowledge and defined as "meaningless" under verificationism.
Ludwig Josef Johann Wittgenstein was an Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language.
Philosophy of language, in the analytical tradition, explored logic, the nature of meaning, and accounts of the mind.
The Tractatus Logico-Philosophicus is the only book-length philosophical work by the Austrian philosopher Ludwig Wittgenstein that was published during his lifetime. The project had a broad goal: to identify the relationship between language and reality and to define the limits of science. It is recognized by philosophers as a significant philosophical work of the twentieth century. G. E. Moore originally suggested the work's Latin title as homage to the Tractatus Theologico-Politicus by Baruch Spinoza.
Seeking grounding in such empiricism as of David Hume,Auguste Comte, and Ernst Mach—along with the positivism of the latter two—they borrowed some perspectives from Immanuel Kant, and found the exemplar of science to be Albert Einstein's general theory of relativity.
David Hume was a Scottish Enlightenment philosopher, historian, economist, and essayist, who is best known today for his highly influential system of philosophical empiricism, scepticism, and naturalism. Hume's empiricist approach to philosophy places him with John Locke, George Berkeley, Francis Bacon and Thomas Hobbes as a British Empiricist. Beginning with his A Treatise of Human Nature (1738), Hume strove to create a total naturalistic science of man that examined the psychological basis of human nature. Against philosophical rationalists, Hume held that passion rather than reason governs human behaviour. Hume argued against the existence of innate ideas, positing that all human knowledge is founded solely in experience.
Isidore Marie Auguste François Xavier Comte was a French philosopher and writer who formulated the doctrine of positivism. He is sometimes regarded as the first philosopher of science in the modern sense of the term. He is also regarded as the founder of the academic discipline sociology.
Ernst Waldfried Josef Wenzel Mach was an Austrian physicist and philosopher, noted for his contributions to physics such as study of shock waves. The ratio of one's speed to that of sound is named the Mach number in his honor. As a philosopher of science, he was a major influence on logical positivism and American pragmatism. Through his criticism of Newton's theories of space and time, he foreshadowed Einstein's theory of relativity.
Logical positivists within the Vienna Circle recognized quickly that the verifiability criterion was too stringent. Notably, all universal generalizations are empirically unverifiable, such that, under verificationism, vast domains of science and reason, such as scientific hypothesis, would be rendered meaningless.
The Vienna Circle of Logical Empiricism was a group of philosophers and scientists drawn from the natural and social sciences, logic and mathematics who met regularly from 1924 to 1936 at the University of Vienna, chaired by Moritz Schlick.
In predicate logic, generalization is a valid inference rule. It states that if has been derived, then can be derived.
A hypothesis is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the available scientific theories. Even though the words "hypothesis" and "theory" are often used synonymously, a scientific hypothesis is not the same as a scientific theory. A working hypothesis is a provisionally accepted hypothesis proposed for further research, in a process beginning with an educated guess or thought.
Rudolf Carnap, Otto Neurath, Hans Hahn and Philipp Frank led a faction seeking to make the verifiability criterion more inclusive, beginning a movement they referred to as the "liberalization of empiricism". Moritz Schlick and Friedrich Waismann led a "conservative wing" that maintained a strict verificationism. Whereas Schlick sought to reduce universal generalizations to frameworks of 'rules' from which verifiable statements can be derived,Hahn argued that the verifiability criterion should accede to less-than-conclusive verifiability. Among other ideas espoused by the liberalization movement were physicalism, over Mach's phenomenalism, coherentism over foundationalism, as well as pragmatism and fallibilism.
In 1936, Carnap sought a switch from verification to confirmation.Carnap's confirmability criterion (confirmationism) would not require conclusive verification (thus accommodating for universal generalizations) but allow for partial testability to establish "degrees of confirmation" on a probabilistic basis. Carnap never succeeded in formalizing his thesis despite employing abundant logical and mathematical tools for this purpose. In all of Carnap's formulations, a universal law's degree of confirmation is zero.
That same year saw the publication of A. J. Ayer's work, Language, Truth and Logic , in which he proposed two types of verification: strong and weak. This system espoused conclusive verification, yet accommodated for probabilistic inclusion where verifiability is inconclusive. Ayer also distinguished between practical and theoretical verifiability. Under the latter, propositions that cannot be verified in practice would still be meaningful if they can be verified in principle.
Karl Popper's The Logic of Scientific Discovery proposed falsificationism as a criterion under which scientific hypothesis would be tenable. Falsificationism would allow hypotheses expressed as universal generalizations, such as "all swans are white", to be provisionally true until falsified by evidence, in contrast to verificationism under which they would be disqualified immediately as meaningless.
Though generally considered a revision of verificationism,Popper intended falsificationism as a methodological standard specific to the sciences rather than as a theory of meaning. Popper regarded scientific hypotheses to be unverifiable, as well as not "confirmable" under Carnap's thesis. He also found non-scientific, metaphysical, ethical and aesthetic statements often rich in meaning and important in the origination of scientific theories.
The 1951 article "Two Dogmas of Empiricism", by Willard Van Orman Quine, attacked the analytic/synthetic division and apparently rendered the verificationist program untenable. Carl Hempel, one of verificationism's greatest internal critics, had recently concluded the same as to the verifiability criterion.In 1958, Norwood Hanson explained that even direct observations must be collected, sorted, and reported with guidance and constraint by theory, which sets a horizon of expectation and interpretation, how observational reports, never neutral, are laden with theory.
Thomas Kuhn's landmark book of 1962, The Structure of Scientific Revolutions —which identified paradigms of science overturned by revolutionary science within fundamental physics—critically destabilized confidence in scientific foundationalism,commonly if erroneously attributed to verificationism. Popper, who had long claimed to have killed verificationism but recognized that some would confuse his falsificationism for more of it, was knighted in 1965. In 1967, John Passmore, a leading historian of 20th-century philosophy, wrote, "Logical positivism is dead, or as dead as a philosophical movement ever becomes"—a general view among philosophers. Logical positivism's fall heralded postpositivism, where Popper's view of human knowledge as hypothetical, continually growing, and open to change ascended, and verificationism became mostly maligned.
Although Karl Popper's falsificationism has been widely criticized by philosophers,Popper has been the only philosopher of science often praised by many scientists. Verificationists, in contrast, have been likened to economists of the 19th century who took circuitous, protracted measures to refuse refutation of their preconceived principles. Still, logical positivists practiced Popper's principles—conjecturing and refuting—until they ran their course, catapulting Popper, initially a contentious misfit, to carry the richest philosophy out of interwar Vienna. And his falsificationism, as did verificationism, poses a criterion, falsifiability, to ensure that empiricism anchors scientific theory.
In a 1979 interview, A J Ayer, who had introduced logical positivism to the English-speaking world in the 1930s, was asked what he saw as its main defects, and answered that "nearly all of it was false".Still, he soon admitted still holding "the same general approach". The "general approach" of empiricism and reductionism—whereby mental phenomena resolve to the material or physical, and philosophical questions largely resolve to ones of language and meaning—has run through Western philosophy since the 17th century and lived beyond logical positivism's fall.
In 1977, Ayer had noted, "The verification principle is seldom mentioned and when it is mentioned it is usually scorned; it continues, however, to be put to work. The attitude of many philosophers reminds me of the relationship between Pip and Magwitch in Dickens's Great Expectations . They have lived on the money, but are ashamed to acknowledge its source".In the late 20th and early 21st centuries, the general concept of verification criteria—in forms that differed from those of the logical positivists—was defended by Bas van Fraassen, Michael Dummett, Crispin Wright, Christopher Peacocke, David Wiggins, Richard Rorty, and others.
A statement, hypothesis, or theory has falsifiability if it is contradicted by a basic statement, which, in an eventual successful or failed falsification, must respectively correspond to a true or hypothetical observation. For example, the claim "all swans are white and have always been white" is falsifiable since it is contradicted by this basic statement: "In 1697, during the Dutch explorer Willem de Vlamingh expedition, there were black swans on the shore of the Swan River in Australia", which in this case is a true observation. The concept is also known by the terms refutable and refutability.
Logical positivism and logical empiricism, which together formed neopositivism, was a movement in Western philosophy whose central thesis was verificationism, a theory of knowledge which asserted that only statements verifiable through empirical observation are meaningful. The movement flourished in the 1920s and 1930s in several European centers.
Rudolf Carnap was a German-language philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism. He is considered "one of the giants among twentieth-century philosophers."
Analytic philosophy is a style of philosophy that became dominant in the Western world at the beginning of the 20th century. The term can refer to one of several things:
Friedrich Albert Moritz Schlick was a German philosopher, physicist, and the founding father of logical positivism and the Vienna Circle.
In philosophy of science and in epistemology, Instrumentalism is a methodological view that ideas are useful instruments, and that the worth of an idea is based on how effective it is in explaining and predicting phenomena. Instrumentalism is a pragmatic philosophy of John Dewey that thought is an instrument for solving practical problems, and that truth is not fixed but changes as problems change. Instrumentalism is the view that scientific theories are useful tools for predicting phenomena instead of true or approximately true descriptions.
Critical rationalism is an epistemological philosophy advanced by Karl Popper. Popper wrote about critical rationalism in his works: The Logic of Scientific Discovery, The Open Society and its Enemies, Conjectures and Refutations, The Myth of the Framework, and Unended Quest. Ernest Gellner is another notable proponent of this approach.
Clarence Irving Lewis, usually cited as C. I. Lewis, was an American academic philosopher and the founder of conceptual pragmatism. First a noted logician, he later branched into epistemology, and during the last 20 years of his life, he wrote much on ethics. The New York Times memorialized him as "a leading authority on symbolic logic and on the philosophic concepts of knowledge and value."
"Two Dogmas of Empiricism" is a paper by analytic philosopher Willard Van Orman Quine published in 1951. According to University of Sydney professor of philosophy Peter Godfrey-Smith, this "paper [is] sometimes regarded as the most important in all of twentieth-century philosophy". The paper is an attack on two central aspects of the logical positivists' philosophy. One is the analytic–synthetic distinction between analytic truths and synthetic truths, explained by Quine as truths grounded only in meanings and independent of facts, and truths grounded in facts. The other is reductionism, the theory that each meaningful statement gets its meaning from some logical construction of terms that refers exclusively to immediate experience.
The demarcation problem in the philosophy of science and epistemology is about how to distinguish between science and non-science, including between science, pseudoscience, and other products of human activity, like art and literature, and beliefs. The debate continues after over two millennia of dialogue among philosophers of science and scientists in various fields, and despite a broad agreement on the basics of the scientific method.
In philosophy and models of scientific inquiry, postpositivism is a metatheoretical stance that critiques and amends positivism. While positivists emphasize independence between the researcher and the researched person, postpositivists argue that theories, background, knowledge and values of the researcher can influence what is observed. Postpositivists pursue objectivity by recognizing the possible effects of biases. While positivists emphasize quantitative methods, postpositivists consider both quantitative and qualitative methods to be valid approaches.
Carl Gustav "Peter" Hempel was a German writer and philosopher. He was a major figure in logical empiricism, a 20th-century movement in the philosophy of science. He is especially well known for his articulation of the deductive-nomological model of scientific explanation, which was considered the "standard model" of scientific explanation during the 1950s and 1960s. He is also known for the raven paradox.
Herbert Feigl was an Austrian philosopher and an early member of the Vienna Circle. He coined the term Nomological danglers.
Positivism is a philosophical theory stating that certain ("positive") knowledge is based on natural phenomena and their properties and relations. Thus, information derived from sensory experience, interpreted through reason and logic, forms the exclusive source of all certain knowledge. Positivism holds that valid knowledge is found only in this a posteriori knowledge.
Gustav Bergmann was an Austrian-born American philosopher. He studied at the University of Vienna and was a member of the Vienna Circle. Bergmann was influenced by the philosophers Moritz Schlick, Friedrich Waismann, and Rudolf Carnap who were members of the Circle. In the United States, he was a professor of philosophy and psychology at the University of Iowa.
Language, Truth, and Logic is a 1936 work of philosophy by Alfred Jules Ayer. It brought some of the ideas of the Vienna Circle and the logical empiricists to the attention of the English-speaking world.
Inductivism is the traditional model of scientific method attributed to Francis Bacon, who in 1620 vowed to subvert allegedly traditional thinking. In the Baconian model, one observes nature, proposes a modest law to generalize an observed pattern, confirms it by many observations, ventures a modestly broader law, and confirms that, too, by many more observations, while discarding disconfirmed laws. The laws grow ever broader but never much exceed careful, extensive observation. Thus, freed from preconceptions, scientists gradually uncover nature's causal and material structure.
An index list of articles about the philosophy of science.
This is a list of articles in analytic philosophy.