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Scientific realism is, at the most general level, the view that the world described by science is the real world, as it is, independent of what we might take it to be. Within
philosophy of scienceThe philosophy of science is concerned with the assumptions, foundations, and implications of science. The field is defined by an interest in one of a set of "traditional" problems or an interest in central or foundational concerns in science...
, it is often framed as an answer to the question "what does the success of science involve?". The debate over what the success of science involves centers primarily on the status of
unobservable entitiesAn unobservable is an entity whose existence, nature, properties, qualities or relations are not directly observable by man. In philosophy of science typical examples of "unobservables" are atomic particles, the force of gravity, causation and beliefs or desires. However, some philosophers An...
apparently talked about by scientific
theoriesThe term theory has two broad sets of meanings, one used in the empirical sciences and the other used in philosophy, mathematics, logic, and across other fields in the humanities. There is considerable difference and even dispute across academic disciplines as to the proper usages of the term...
. Roughly put, scientific realism is the
thesisA dissertation or thesis is a document submitted in support of candidature for a degree or professional qualification presenting the author's research and findings...
that the unobservable things talked about by science are little different (in terms of ontological status) from ordinary observable things (such as tables and chairs).
Main features of scientific realism
Scientific realism involves 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. For example, one might hold realist attitudes toward physics, chemistry and biology, and not toward economics, psychology and sociology.
According to scientific realism, an ideal scientific theory has the following features:
- The claims the theory makes are either true or false, depending on whether the entities talked about by the theory exist and are correctly described by the theory. This is the semantic commitment of scientific realism.
- The entities described by the scientific theory exist objectively and mind-independently. This is the metaphysical
Metaphysics investigates principles of reality transcending those of any particular science. Cosmology and ontology are traditional branches of metaphysics. It is concerned with explaining the fundamental nature of being and the world...
commitment of scientific realism.
- There are reasons to believe some significant portion of what the theory says. This is the epistemological
Epistemology or theory of knowledge is the branch of philosophy concerned with the nature and scope of knowledge...
commitment.
Combining the first and the second claim entails that an ideal scientific theory says true things about genuinely existing entities. The third claim says that we have reasons to believe that the things said about these entities are true.
Scientific realism usually holds that science makes progress, i.e. scientific theories usually get successfully better, or, rather, answer more and more questions. For this reason, many people, scientific realist 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.
History of scientific realism
Scientific realism is related to much older philosophical positions including
rationalismIn epistemology and in its modern sense, rationalism is "any view appealing to reason as a source of knowledge or justification" . In more technical terms it is a method or a theory "in which the criterion of the truth is not sensory but intellectual and deductive"...
and
realismContemporary philosophical realism is the belief in a reality that is completely ontologically independent of our conceptual schemes, linguistic practices, beliefs, etc. Philosophers who profess realism also typically believe that truth consists in a belief's correspondence to reality...
. 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 positivismLogical positivism is a school of philosophy that combines empiricism, the idea that observational evidence is indispensable for knowledge of the world, with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions in epistemology.[See, e.g., : ...]
. 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:
- The verification theory of meaning (for which see Hempel
Carl Gustav "Peter" Hempel was a philosopher of science and a major figure in 20th-century logical empiricism...
(1950)).
- Troubles with the analytic-synthetic distinction (for which see Quine (1950)).
- The theory ladenness of observation (for which see Kuhn
Thomas Samuel Kuhn was an American intellectual who wrote extensively on the history of science and developed several important notions in the sociology and philosophy of science.-Life:...
(1970) and Quine (1960)).
- Difficulties moving from the observationality of terms to observationality of sentences (for which see Putnam
Hilary Whitehall Putnam is an American philosopher who has been a central figure in analytic philosophy since the 1960s, especially in philosophy of mind, philosophy of language, and philosophy of science...
(1962)).
- The vagueness of the observational-theoretical distinction (for which see Maxwell (1962)).
These difficulties for logical positivism suggest, but do not entail, scientific realism, and lead to the development of realism as a philosophy of science.
Realism became the dominant philosophy of science after positivism. Bas van Fraassen developed constructive empiricism as an alternative to realism. Responses to van Fraassen have sharpened realist positions and lead to some revisions of scientific realism.
Arguments for and against 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{{Citation needed|date=July 2009}}. Many realists{{Who|date=July 2009}} 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 reasoningAbduction is a method of logical inference introduced by Charles Sanders Peirce which comes prior to induction and deduction for which the colloquial name is to have a "hunch". Abductive reasoning starts when an inquirer considers of a set of seemingly unrelated facts, armed with an intuition that...
or "inference to the best explanation"{{Citation needed|date=July 2009}}. Scientific realists{{Who|date=July 2009}} point to the success of scientific theories in predicting and explaining a variety of phenomena, and argue that from this we can infer that our scientific theories (or at least the best ones) provide true descriptions of the world, or approximately so.
On the other hand,
pessimistic inductionIn 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....
, 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 effluvial theory of static electricity is an empirically successful theory whose central unobservable terms have been replaced by later theories. Realists{{Who|date=July 2009}} 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{{Citation needed|date=July 2009}}. For example,
Albert EinsteinAlbert Einstein was a theoretical physicist. His many contributions to physics include the special and general theories of relativity, the founding of relativistic cosmology, the first post-Newtonian expansion, explaining the perihelion advance of Mercury, prediction of the deflection of...
's theory of
special relativitySpecial relativity is the physical theory of measurement in inertial frames of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies"...
showed that the concept of the luminiferous ether could be dropped because it had contributed nothing to the success of the theories of
mechanicsMechanics is the branch of physics concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effect of the bodies on their environment....
and
electromagnetismElectromagnetism is the physics of the electromagnetic field, a field that exerts a force on particles with the property of electric charge and is reciprocally affected by the presence and motion of such particles....
. On the other hand, when theory replacement occurs, a well-supported concept, such as the concept of
atomThe atom is a basic unit of matter consisting of a dense, central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...
s, is not dropped but is incorporated into the new theory in some form.
Also against scientific realism
social constructivistsConstructivist epistemology is an epistemological perspective in philosophy about the nature of scientific knowledge. Constructivists maintain that scientific knowledge is constructed by scientists and not discovered from the world. Constructivism believes that there is no single valid methodology...
{{Who|date=July 2009}} argue that scientific realism is unable to account for the rapid change that occurs in scientific knowledge during periods of revolution{{Who|date=July 2009}}. Constructivists may also argue{{Who|date=July 2009}} that the success of theories is only a part of the construction{{Citation needed|date=July 2009}}. However, these arguments ignore the fact that many scientists are not realists{{Who|date=July 2009}}{{Citation needed|date=July 2009}}. In fact, during what is perhaps the most notable example of revolution in science—the development of
quantum mechanicsQuantum mechanics is a set of principles describing the physical reality at the atomic level of matter and the subatomic . These descriptions include the simultaneous wave-like and particle-like behavior of both matter and radiation...
in the 1920s—the dominant philosophy of science was
logical positivismLogical positivism is a school of philosophy that combines empiricism, the idea that observational evidence is indispensable for knowledge of the world, with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions in epistemology.[See, e.g., : ...]
. The alternative realist
Bohm interpretationThe Bohm or Bohmian interpretation of quantum mechanics, which Bohm called the causal, or later, the ontological interpretation, is an interpretation postulated by David Bohm in 1952 as an alternative to the standard Copenhagen interpretation. The Bohm interpretation grew out of the search for...
and
many-worlds interpretationThe many-worlds interpretation is an interpretation of quantum mechanics.It is also known as MWI, the relative state formulation, theory of the universal wavefunction, parallel universes, many-universes interpretation or just many worlds.Many-worlds asserts the objective reality of the...
of quantum mechanics do not make such a revolutionary break with the concepts of
classical physicsWhat "classical physics" refers to depends on the context. When discussing special relativity, it refers to the Newtonian physics which preceded relativity, i.e. the branches of physics based on principles developed before the rise of relativity and quantum mechanics...
.
Another argument against scientific realism{{Who|date=July 2009}}, deriving from the
underdetermination problemUnderdetermination is a term used in the discussion of theories and their relation to the evidence that is cited to support them. Arguments from underdetermination are used to support epistemic relativism by claiming that there is no good way to certify a theory based on any set of evidence...
, is not so historically motivated as these others{{Citation needed|date=July 2009}}. It claims{{Who|date=July 2009}} that observational data can in principle be explained by multiple theories that are mutually incompatible{{Citation needed|date=July 2009}}. Realists{{Who|date=July 2009}} counter by saying that there have been few actual cases of underdetermination in the history of science{{Citation needed|date=July 2009}}. 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
observedObservation is either an activity of a living being , consisting of receiving knowledge of the outside world through the senses, or the recording of data using scientific instruments. The term may also refer to any datum collected during this activity.-Observation in science:A scientific method...
{{Citation needed|date=July 2009}}. For example, we could not theorize that
dinosaur{{Otheruses}}{{pp-semi-protected|small=yes}}{{Otheruses}}{{pp-semi-protected|small=yes}}{{Taxobox|name = Dinosaurs|fossil_range = {{Fossil range|230|65|earliest=230|latest=0|PS=
Descendant taxon Aves survives to present.}}|image = field_dinos_2.jpg...
s once lived based on the
fossilFossils are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous rock formations and sedimentary layers is known as the fossil record...
evidence because other theories (e.g., that the fossils are clever hoaxes) can account for the same data. Realists claim that{{Who|date=July 2009}}, in addition to empirical adequacy, there are other criteria for theory choice, such as parsimony{{Citation needed|date=July 2009}}.
See also
- Constructivist epistemology
Constructivist epistemology is an epistemological perspective in philosophy about the nature of scientific knowledge. Constructivists maintain that scientific knowledge is constructed by scientists and not discovered from the world. Constructivism believes that there is no single valid methodology...
- Constructive empiricism
In philosophy, constructive empiricism is a form of empiricism. Bas C. van Fraassen is nearly solely responsible for the initial development of constructive empiricism; its historically most important presentation appears in his The Scientific Image...
- Confirmation holism
Confirmation holism, also called epistemological holism is the claim that a single scientific theory cannot be tested in isolation; a test of one theory always depends on other theories and hypotheses....
- Critical realism
In the philosophy of perception, critical realism is the theory that some of our sense-data can and do accurately represent external objects, properties, and events, while other of our sense-data do not accurately represent any external objects, properties, and events.Critical...
- Entity realism
Entity realism is a philosophical position within the debate about scientific realism. Whereas traditional scientific realism argues that our best scientific theories are true, or approximately true, or closer to the truth than their predecessors, entity realism does not commit itself to judgments...
- Instrumentalism
In the philosophy of science, instrumentalism is the view that a concept or theory should be evaluated by how effectively it explains and predicts phenomena, as opposed to how accurately it describes objective reality....
- Naïve realism
Naïve realism, also known as direct realism or common sense realism, is a common sense theory of perception."Naïve realism claims that the world is pretty much as common sense would have it. All objects are composed of matter, they occupy space, and have properties such as size, shape, texture,...
- Scientific materialism
- Structural realism
External links
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