Scientific realism is the view that the universe described by science is real regardless of how it may be interpreted.
Within philosophy of science, this view is often an answer to the question "how is the success of science to be explained?" The discussion on the success of science in this context centers primarily on the status of unobservable entities apparently talked about by scientific theories. Generally, those who are scientific realists assert that one can make valid claims about unobservables (viz., that they have the same ontological status) as observables, as opposed to instrumentalism.
Scientific realism involves the two basic positions. First, it is a set of claims about the features of an ideal scientific theory; an ideal theory is the sort of theory science aims to produce. Second, it is the commitment that science will eventually produce theories very much like an ideal theory and that science has done pretty well thus far in some domains. It is important to note that one might be a scientific realist regarding some sciences while not being a realist regarding others.
According to scientific realism, an ideal scientific theory has the following features:
Combining the first and the second claim entails that an ideal scientific theory says definite things about genuinely existing entities. The third claim says that we have reasons to believe that many scientific claims about these entities are true, but not all.
Scientific realism usually holds that science makes progress, i.e. scientific theories usually get successively better, or, rather, answer more and more questions. For this reason, many people, scientific realists or otherwise, hold that realism should make sense of the progress of science in terms of theories being successively more like the ideal theory that scientific realists describe.
The following claims are typical of those held by scientific realists. Due to the wide disagreements over the nature of science's success and the role of realism in its success, a scientific realist would agree with some but not all of the following positions.
Scientific realism is related to much older philosophical positions including rationalism and metaphysical realism. However, it is a thesis about science developed in the twentieth century. Portraying scientific realism in terms of its ancient, medieval, and early modern cousins is at best misleading.
Scientific realism is developed largely as a reaction to logical positivism. Logical positivism was the first philosophy of science in the twentieth century and the forerunner of scientific realism, holding that a sharp distinction can be drawn between observational terms and theoretical terms, the latter capable of semantic analysis in observational and logical terms.
Logical positivism encountered difficulties with:
These difficulties for logical positivism suggest, but do not entail, scientific realism, and led to the development of realism as a philosophy of science.
Realism became the dominant philosophy of science after positivism. Bas van Fraassen in his book The Scientific Image (1980) developed constructive empiricism as an alternative to realism. Responses to van Fraassen have sharpened realist positions and lead to some revisions of scientific realism.
One of the main arguments for scientific realism centers on the notion that scientific knowledge is progressive in nature, and that it is able to predict phenomena successfully. Many scientific realists (e.g., Ernan McMullin, Richard Boyd) think the operational success of a theory lends credence to the idea that its more unobservable aspects exist, because they were how the theory reasoned its predictions. For example, a scientific realist would argue that science must derive some ontological support for atoms from the outstanding phenomenological success of all the theories using them.
Arguments for scientific realism often appeal to abductive reasoning or "inference to the best explanation" (Lipton, 2004). For instance, one argument commonly used—the "miracle argument" or "no miracles argument"—starts out by observing that scientific theories are highly successful in predicting and explaining a variety of phenomena, often with great accuracy. Thus, it is argued that the best explanation—the only explanation that renders the success of science to not be what Hilary Putnam calls "a miracle"—is the view that our scientific theories (or at least the best ones) provide true descriptions of the world, or approximately so.
Bas van Fraassen replies with an evolutionary analogy: "I claim that the success of current scientific theories is no miracle. It is not even surprising to the scientific (Darwinist) mind. For any scientific theory is born into a life of fierce competition, a jungle red in tooth and claw. Only the successful theories survive—the ones which in fact latched on to actual regularities in nature." (The Scientific Image, 1980)
Pessimistic induction, one of the main arguments against realism, argues that the history of science contains many theories once regarded as empirically successful but which are now believed to be false. Additionally, the history of science contains many empirically successful theories whose unobservable terms are not believed to genuinely refer. For example, the effluvium theory of static electricity (a theory of the 16th Century physicist William Gilbert) is an empirically successful theory whose central unobservable terms have been replaced by later theories.
Realists reply that replacement of particular realist theories with better ones is to be expected due to the progressive nature of scientific knowledge, and when such replacements occur only superfluous unobservables are dropped. For example, Albert Einstein's theory of special relativity showed that the concept of the luminiferous ether could be dropped because it had contributed nothing to the success of the theories of mechanics and electromagnetism. On the other hand, when theory replacement occurs, a well-supported concept, such as the concept of atoms, is not dropped but is incorporated into the new theory in some form. These replies can lead scientific realists to structural realism.
Social constructivists might argue that scientific realism is unable to account for the rapid change that occurs in scientific knowledge during periods of revolution. Constructivists may also argue that the success of theories is only a part of the construction. However, these arguments ignore the fact that many scientists are not realists. In fact, during what is perhaps the most notable example of revolution in science—the development of quantum mechanics in the 1920s—the dominant philosophy of science was logical positivism. The alternative realist Bohm interpretation and many-worlds interpretation of quantum mechanics do not make such a revolutionary break with the concepts of classical physics.
Another argument against scientific realism, deriving from the underdetermination problem, is not so historically motivated as these others. It claims that observational data can in principle be explained by multiple theories that are mutually incompatible. Realists might counter by saying that there have been few actual cases of underdetermination in the history of science. Usually the requirement of explaining the data is so exacting that scientists are lucky to find even one theory that fulfills it. Furthermore, if we take the underdetermination argument seriously, it implies that we can know about only what we have directly observed. For example, we could not theorize that dinosaurs once lived based on the fossil evidence because other theories (e.g., that the fossils are clever hoaxes) can account for the same data.
Alan Musgrave (; born 1940) is an English-born New Zealand philosopher.Australian philosophy
Australian philosophy refers to the philosophical tradition of the people of Australia and of its citizens abroad.Constructive empiricism
In philosophy, constructive empiricism (also empiricist structuralism) is a form of empiricism.Danish philosophy
Danish philosophy has a long tradition as part of Western philosophy.
Perhaps the most influential Danish philosopher was Søren Kierkegaard, the creator of Christian existentialism, which inspired the philosophical movement of Existentialism. Kierkegaard had a few Danish followers, including Harald Høffding, who later in his life moved on to join the movement of positivism. Among Kierkegaard's other followers include Jean-Paul Sartre who was impressed with Kierkegaard's views on the individual, and Rollo May, who helped create humanistic psychology.David Malet Armstrong
David Malet Armstrong (8 July 1926 – 13 May 2014), often D. M. Armstrong, was an Australian philosopher. He is well known for his work on metaphysics and the philosophy of mind, and for his defence of a factualist ontology, a functionalist theory of the mind, an externalist epistemology, and a necessitarian conception of the laws of nature. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 2008.Keith Campbell said that Armstrong's contributions to metaphysics and epistemology "helped to shape philosophy's agenda and terms of debate", and that Armstrong's work "always concerned to elaborate and defend a philosophy which is ontically economical, synoptic, and compatibly continuous with established results in the natural sciences".Entity realism
Entity realism (also selective realism), sometimes equated with referential realism, is a philosophical position within the debate about scientific realism. It is a variation of realism (independently proposed by Stanford School philosophers Nancy Cartwright and Ian Hacking in 1983) that restricts warranted belief to only certain entities.Instrumentalism
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.The truth of an idea is determined by its success in the active solution of a problem. A successful scientific theory reveals nothing known either true or false about nature's unobservable objects, properties or processes. Scientific theories are assessed on their usefulness in generating predictions and in confirming those predictions in data and observations, and not on their ability to explain the truth value of some unobservable phenomenon. The question of "truth" is not taken into account one way or the other. According to instrumentalists, scientific theory is merely a tool whereby humans predict observations in a particular domain of nature by formulating laws, which state or summarize regularities, while theories themselves do not reveal supposedly hidden aspects of nature that somehow explain these laws. Initially a novel perspective introduced by Pierre Duhem in 1906, instrumentalism is largely the prevailing theory that underpins the practice of physicists today.Rejecting scientific realism's ambitions to uncover metaphysical truth about nature, instrumentalism is usually categorized as an antirealism, although its mere lack of commitment to scientific theory's realism can be termed nonrealism. Instrumentalism merely bypasses debate concerning whether, for example, a particle spoken about in particle physics is a discrete entity enjoying individual existence, or is an excitation mode of a region of a field, or is something else altogether. Instrumentalism holds that theoretical terms need only be useful to predict the phenomena, the observed outcomes.There are multiple versions of instrumentalism. Instrumentalism is a variety of scientific anti-realism.James Robert Brown
James Robert Brown (born 1949 in Montreal, Quebec) is a Canadian philosopher of science.
He is a Professor of philosophy at the University of Toronto. In the philosophy of mathematics, he has advocated mathematical Platonism, and in the philosophy of science he has defended scientific realism mostly against anti-realist views associated with social constructivism. He is largely known for his pioneering writing about thought experiments in science and in general.
In 2007, he was made a Fellow of the Royal Society of Canada.Naïve realism
In philosophy of mind, naïve realism, also known as direct realism, common sense realism or perceptual realism, is the idea that the senses provide us with direct awareness of objects as they really are. Objects obey the laws of physics and retain all their properties whether or not there is anyone to observe them. They are composed of matter, occupy space and have properties, such as size, shape, texture, smell, taste and colour, that are usually perceived correctly.
In contrast, some forms of idealism claim that no world exists apart from mind-dependent ideas, and some forms of skepticism say we cannot trust our senses. Naïve realism is known as direct as against indirect or representational realism when its arguments are developed to counter the latter position, also known as epistemological dualism; that our conscious experience is not of the real world but of an internal representation of the world.Operational definition
An operational definition is the articulation of operationalization (or statement of procedures) used in defining the terms of a process (or set of validation tests) needed to determine the nature of an item or phenomenon (a variable, term, or object) and its properties such as duration, quantity, extension in space, chemical composition, etc. Since the degree of operationalization can vary itself, it can result in a more or less operational definition. The procedures included in definitions should be repeatable by anyone or at least by peers.
An example of operational definition of the term weight of an object, operationalized to a degree, would be the following: "weight is the numbers that appear when that object is placed on a weighing scale". According to it, the weight can be any of the numbers shown on the scale after and including the very moment the object is put on it. Clearly, the inclusion of the moment when one can start reading the numbers on the scale would make it more fully an operational definition. Nonetheless, it is still in contrast to those purely theoretical definitions.Pessimistic induction
In the philosophy of science, the pessimistic induction, also known as the pessimistic meta-induction, is an argument which seeks to rebut scientific realism, particularly the scientific realist's notion of epistemic optimism.Philosophical realism
In metaphysics, realism about a given object is the view that this object exists in reality independently of our conceptual scheme. In philosophical terms, these objects are ontologically independent of someone's conceptual scheme, perceptions, linguistic practices, beliefs, etc.
Realism can be applied to many philosophically interesting objects and phenomena: other minds, the past or the future, universals, mathematical entities (such as natural numbers), moral categories, the physical world, and thought.
Realism can also be a view about the nature of reality in general, where it claims that the world exists independent of the mind, as opposed to non-realist views (like some forms of skepticism and solipsism, which question our ability to assert the world is independent of our mind). Philosophers who profess realism often claim that truth consists in a correspondence between cognitive representations and reality.Realists tend to believe that whatever we believe now is only an approximation of reality but that the accuracy and fullness of understanding can be improved. In some contexts, realism is contrasted with idealism. Today it is more usually contrasted with anti-realism, for example in the philosophy of science.
The oldest use of the term "realism" appears in medieval scholastic interpretations and adaptations of ancient Greek philosophy.Reality
Reality is the sum or aggregate of all that is real or existent, as opposed to that which is merely imaginary. The term is also used to refer to the ontological status of things, indicating their existence. In physical terms, reality is the totality of the universe, known and unknown. Philosophical questions about the nature of reality or existence or being are considered under the rubric of ontology, which is a major branch of metaphysics in the Western philosophical tradition. Ontological questions also feature in diverse branches of philosophy, including the philosophy of science, philosophy of religion, philosophy of mathematics, and philosophical logic. These include questions about whether only physical objects are real (i.e., Physicalism), whether reality is fundamentally immaterial (e.g., Idealism), whether hypothetical unobservable entities posited by scientific theories exist, whether God exists, whether numbers and other abstract objects exist, and whether possible worlds exist.Richard Boyd
Richard Newell Boyd (born 19 May 1942, Washington, D.C.) is an American philosopher.Stathis Psillos
Stathis Psillos (; Greek: Στάθης Ψύλλος; born 22 June 1965) is a Greek philosopher of science. He is Professor of Philosophy of Science and Metaphysics at the University of Athens, Greece and a member of the Rotman Institute of Philosophy—Engaging Science of the University of Western Ontario. In 2013–15, he held the Rotman Canada Research Chair in Philosophy of Science at the University of Western Ontario, Canada.Psillos is best known for his work in scientific realism and the metaphysics of science. He is a notable defender of semantic realism about scientific discourse (the view that theoretical assertions are no less meaningful than observational ones) and also a notable critic of semantic anti-realism about scientific discourse (the view that theoretical terms of past scientific theories often fail to refer to anything) and structural realism.In 2015, he was classified among the 91 most cited living philosophers with public Google Scholar pages.Structuralism (philosophy of science)
Structuralism (also known as scientific structuralism or as the structuralistic theory-concept) is an active research program in the philosophy of science, which was first developed in the late 1960s and throughout the 1970s by several analytic philosophers.Turkish philosophy
Turkish philosophy has long been affected by Islam and the country's proximity to Greece and ancient Greek philosophy.Unobservable
An unobservable (also called impalpable) is an entity whose existence, nature, properties, qualities or relations are not directly observable by humans. In philosophy of science, typical examples of "unobservables" are the force of gravity, causation and beliefs or desires.However, some philosophers (George Berkeley for example) also characterize all objects—trees, tables, other minds, microorganisms, every thing to which humans ascribe as the thing causing their perception—as unobservable.
"Unobservables" is a reference similar to Immanuel Kant's distinction between noumena (things-in-themselves, i.e., raw things in their necessarily unknowable state, before they pass through the formalizing apparatus of the senses and the mind in order to become perceived objects) and phenomena (the perceived object). According to Kant, humans can never know noumena; all that humans know is the phenomena. Kant's distinction is similar to John Locke's distinction between primary and secondary qualities. Secondary qualities are what humans perceive such as redness, chirping, heat, mustiness or sweetness. Primary qualities would be the actual qualities of the things themselves which give rise to the secondary qualities which humans perceive.
The ontological nature and epistemological issues concerning unobservables is a central topic in philosophy of science. The notion that a given unobservable exists is referred to as scientific realism, in contrast to instrumentalism, the notion that unobservables such as atoms are useful models but don't necessarily exist.
W. V. Metcalf distinguishes three kinds of unobservables. One is the logically unobservable, which involves a contradiction. An example would be a length which is both longer and shorter than a given length. The second is the practically unobservable, that which we can conceive of as observable by the known sense-faculties of man but we are prevented from observing by practical difficulties. The third kind is the physically unobservable, that which can never be observed by any existing sense-faculties of man.