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 natural phenomena. According to instrumentalists, a successful scientific theory reveals nothing known either true or false about nature's unobservable objects, properties or processes.^[1] 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.^[2] Instrumentalism is a perspective originally introduced by Pierre Duhem in 1906.^[2]

Rejecting scientific realism's ambitions to uncover metaphysical truth about nature,^[2] 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.^[3]^[4]^[5] Instrumentalism holds that theoretical terms need only be useful to predict the phenomena, the observed outcomes.^[3]

There are multiple versions of instrumentalism.

^
*Anjan Chakravartty, Chakravartty, Anjan (April 27, 2011). "Scientific Realism". Retrieved August 13, 2019 – via plato.stanford.edu. {{cite journal}}: Cite journal requires |journal= (help), §4 "Antirealism: Foils for scientific realism: §4.1: "Empiricism", in Edward N. Zalta, ed, The Stanford Encyclopedia of Philosophy, Summer 2013 edn: "Traditionally, instrumentalists maintain that terms for unobservables, by themselves, have no meaning; construed literally, statements involving them are not even candidates for truth or falsity. The most influential advocates of instrumentalism were the logical empiricists (or logical positivists), including Carnap and Hempel, famously associated with the Vienna Circle group of philosophers and scientists as well as important contributors elsewhere. In order to rationalize the ubiquitous use of terms which might otherwise be taken to refer to unobservables in scientific discourse, they adopted a non-literal semantics according to which these terms acquire meaning by being associated with terms for observables (for example, 'electron' might mean 'white streak in a cloud chamber'), or with demonstrable laboratory procedures (a view called 'operationalism'). Insuperable difficulties with this semantics led ultimately (in large measure) to the demise of logical empiricism and the growth of realism. The contrast here is not merely in semantics and epistemology: a number of logical empiricists also held the neo-Kantian view that ontological questions 'external' to the frameworks for knowledge represented by theories are also meaningless (the choice of a framework is made solely on pragmatic grounds), thereby rejecting the metaphysical dimension of realism (as in Carnap 1950)".
- Samir Okasha, Philosophy of Science: A Very Short Introduction (New York: Oxford University Press, 2002), p. 62: "Strictly we should distinguish two sorts of anti-realism. According to the first sort, talk of unobservable entities is not to be understood literally at all. So when a scientist pus forward a theory about electrons, for example, we should not take him to be asserting the existence of entities called 'electrons'. Rather, his talk of electrons is metaphorical. This form of anti-realism was popular in the first half of the 20th century, but few people advocate it today. It was motivated largely by a doctrine in the philosophy of language, according to which it is not possible to make meaningful assertions about things that cannot in principle be observed, a doctrine that few contemporary philosophers accept. The second sort of anti-realism accepts that talk of unobservable entities should be taken at face value: if a theory says that electrons are negatively charged, it is true if electrons do exist and are negatively charged, but false otherwise. But we will never know which, says the anti-realist. So the correct attitude towards the claims that scientists make about unobservable reality is one of total agnosticism. They are either true or false, but we are incapable of finding out which. Most modern anti-realism is of this second sort".
^ ^a ^b ^c Roberto Torretti, The Philosophy of Physics (Cambridge: Cambridge University Press, 1999), pp. 242–43: "Like Whewell and Mach, Duhem was a practicing scientist who devoted an important part of his adult life to the history and philosophy of physics. ... His philosophy is contained in La théorie physique: son objet, sa structure [The Aim and Structure of Physical Theory] (1906), which may well be, to this day, the best overall book on the subject. Its main theses, although quite novel when first put forward, have in the meantime become commonplace, so I shall review them summarily without detailed argument, just to associate them with his name. But first I ought to say that neither in the first nor in the second (1914) edition of his book did Duhem take into account—or even so much as mention—the deep changes that were then taking place in physics. Still, the subsequent success and current entrenchment of Duhem's ideas are due above all to their remarkable agreement with—and the light they throw on—the practice of mathematical physics in the twentieth century. In the first part of La théorie physique, Duhem contrasts two opinions concerning the aim of physical theory. For some authors, it ought to furnish 'the explanation of a set of experimentally established laws', while for others it is 'an abstract system whose aim is to summarize and logically classify a set of experimental laws, without pretending to explain these laws' (Duhem 1914, p. 3). Duhem resolutely sides with the latter. His rejection of the former rests on his understanding of 'explanation' ('explication' in French), which he expresses as follows: 'To explain, explicare, is to divest reality from the appearances which enfold it like veils, in order to see the reality face to face' (pp 3–4). Authors in the first group expect from physics the true vision of things-in-themselves that religious myth and philosophical speculation have hitherto been unable to supply. Their explanation makes no sense unless (i) there is, 'beneath the sense appearances revealed to us by our perceptions, [...] a reality different from these appearances' and (ii) we know 'the nature of the elements which constitute' that reality (p 7). Thus, physical theory cannot explain—in the stated sense—the laws established by experiment unless it depends on metaphysics and thus remains subject to the interminable disputes of metaphysicians. Worse still, the teachings of no metaphysical school are sufficiently detailed and precise to account for all of the elements of physical theory (p 18). Duhem instead assigns to physical theories a more modest but autonomous and readily attainable aim: 'A physical theory is not an explanation. It is a system of mathematical propositions, derived from a small number of principles, whose purpose is to represent a set of experimental laws as simply, as completely, and as exactly as possible (Duhem 1914, p. 24)".
^ ^a ^b P Kyle Stanford, Exceeding Our Grasp: Science, History, and the Problem of Unconceived Alternatives (New York: Oxford University Press, 2006), p. 198.
^ Roberto Torretti, The Philosophy of Physics (Cambridge: Cambridge University Press, 1999), pp. 396–97, including quote: "First, quantum field theories have been the working theories at the frontline of physics for over 30 years. Second, these theories appear to do away with the familiar conception of physical systems as aggregates of substantive individual particles. This conception was already undermined by Bose–Einstein and Fermi–Dirac statistics (§6.1.4), according to which the so-called particles cannot be assigned a definite trajectory in ordinary space. But quantum field theories go a long step further and—or so it would seem—conceive 'particles' as excitation modes of the field. This, I presume, motivated Howard Stein's saying that 'the quantum theory of fields is the contemporary locus of metaphysical research' (1970, p. 285). Finally, the very fact that physicists conspicuously and fruitfully resort to unperspicacious theories can teach us something about the aim and reach of science. Here is how physicists work, dirty-handed, in their everyday practice, a far cry from what is taught at the Sunday school of the 'scientific worldview' ".
^ Meinard Kuhlmann, "Physicists debate whether the world is made of particles or fields—or something else entirely, Scientific American, 2013 Aug;309(2).

[1] *Anjan Chakravartty, Chakravartty, Anjan (April 27, 2011). "Scientific Realism". Retrieved August 13, 2019 – via plato.stanford.edu. {{cite journal}}: Cite journal requires |journal= (help), §4 "Antirealism: Foils for scientific realism: §4.1: "Empiricism", in Edward N. Zalta, ed, The Stanford Encyclopedia of Philosophy, Summer 2013 edn: "Traditionally, instrumentalists maintain that terms for unobservables, by themselves, have no meaning; construed literally, statements involving them are not even candidates for truth or falsity. The most influential advocates of instrumentalism were the logical empiricists (or logical positivists), including Carnap and Hempel, famously associated with the Vienna Circle group of philosophers and scientists as well as important contributors elsewhere. In order to rationalize the ubiquitous use of terms which might otherwise be taken to refer to unobservables in scientific discourse, they adopted a non-literal semantics according to which these terms acquire meaning by being associated with terms for observables (for example, 'electron' might mean 'white streak in a cloud chamber'), or with demonstrable laboratory procedures (a view called 'operationalism'). Insuperable difficulties with this semantics led ultimately (in large measure) to the demise of logical empiricism and the growth of realism. The contrast here is not merely in semantics and epistemology: a number of logical empiricists also held the neo-Kantian view that ontological questions 'external' to the frameworks for knowledge represented by theories are also meaningless (the choice of a framework is made solely on pragmatic grounds), thereby rejecting the metaphysical dimension of realism (as in Carnap 1950)".
Samir Okasha, Philosophy of Science: A Very Short Introduction (New York: Oxford University Press, 2002), p. 62: "Strictly we should distinguish two sorts of anti-realism. According to the first sort, talk of unobservable entities is not to be understood literally at all. So when a scientist pus forward a theory about electrons, for example, we should not take him to be asserting the existence of entities called 'electrons'. Rather, his talk of electrons is metaphorical. This form of anti-realism was popular in the first half of the 20th century, but few people advocate it today. It was motivated largely by a doctrine in the philosophy of language, according to which it is not possible to make meaningful assertions about things that cannot in principle be observed, a doctrine that few contemporary philosophers accept. The second sort of anti-realism accepts that talk of unobservable entities should be taken at face value: if a theory says that electrons are negatively charged, it is true if electrons do exist and are negatively charged, but false otherwise. But we will never know which, says the anti-realist. So the correct attitude towards the claims that scientists make about unobservable reality is one of total agnosticism. They are either true or false, but we are incapable of finding out which. Most modern anti-realism is of this second sort".

[2] Samir Okasha, Philosophy of Science: A Very Short Introduction (New York: Oxford University Press, 2002), p. 62: "Strictly we should distinguish two sorts of anti-realism. According to the first sort, talk of unobservable entities is not to be understood literally at all. So when a scientist pus forward a theory about electrons, for example, we should not take him to be asserting the existence of entities called 'electrons'. Rather, his talk of electrons is metaphorical. This form of anti-realism was popular in the first half of the 20th century, but few people advocate it today. It was motivated largely by a doctrine in the philosophy of language, according to which it is not possible to make meaningful assertions about things that cannot in principle be observed, a doctrine that few contemporary philosophers accept. The second sort of anti-realism accepts that talk of unobservable entities should be taken at face value: if a theory says that electrons are negatively charged, it is true if electrons do exist and are negatively charged, but false otherwise. But we will never know which, says the anti-realist. So the correct attitude towards the claims that scientists make about unobservable reality is one of total agnosticism. They are either true or false, but we are incapable of finding out which. Most modern anti-realism is of this second sort".

[Torretti-Duhem-2] Roberto Torretti, The Philosophy of Physics (Cambridge: Cambridge University Press, 1999), pp. 242–43: "Like Whewell and Mach, Duhem was a practicing scientist who devoted an important part of his adult life to the history and philosophy of physics. ... His philosophy is contained in La théorie physique: son objet, sa structure [The Aim and Structure of Physical Theory] (1906), which may well be, to this day, the best overall book on the subject. Its main theses, although quite novel when first put forward, have in the meantime become commonplace, so I shall review them summarily without detailed argument, just to associate them with his name. But first I ought to say that neither in the first nor in the second (1914) edition of his book did Duhem take into account—or even so much as mention—the deep changes that were then taking place in physics. Still, the subsequent success and current entrenchment of Duhem's ideas are due above all to their remarkable agreement with—and the light they throw on—the practice of mathematical physics in the twentieth century. In the first part of La théorie physique, Duhem contrasts two opinions concerning the aim of physical theory. For some authors, it ought to furnish 'the explanation of a set of experimentally established laws', while for others it is 'an abstract system whose aim is to summarize and logically classify a set of experimental laws, without pretending to explain these laws' (Duhem 1914, p. 3). Duhem resolutely sides with the latter. His rejection of the former rests on his understanding of 'explanation' ('explication' in French), which he expresses as follows: 'To explain, explicare, is to divest reality from the appearances which enfold it like veils, in order to see the reality face to face' (pp 3–4). Authors in the first group expect from physics the true vision of things-in-themselves that religious myth and philosophical speculation have hitherto been unable to supply. Their explanation makes no sense unless (i) there is, 'beneath the sense appearances revealed to us by our perceptions, [...] a reality different from these appearances' and (ii) we know 'the nature of the elements which constitute' that reality (p 7). Thus, physical theory cannot explain—in the stated sense—the laws established by experiment unless it depends on metaphysics and thus remains subject to the interminable disputes of metaphysicians. Worse still, the teachings of no metaphysical school are sufficiently detailed and precise to account for all of the elements of physical theory (p 18). Duhem instead assigns to physical theories a more modest but autonomous and readily attainable aim: 'A physical theory is not an explanation. It is a system of mathematical propositions, derived from a small number of principles, whose purpose is to represent a set of experimental laws as simply, as completely, and as exactly as possible (Duhem 1914, p. 24)".

[Stanford-3] P Kyle Stanford, Exceeding Our Grasp: Science, History, and the Problem of Unconceived Alternatives (New York: Oxford University Press, 2006), p. 198.

[Torretti-pp396-97-4] Roberto Torretti, The Philosophy of Physics (Cambridge: Cambridge University Press, 1999), pp. 396–97, including quote: "First, quantum field theories have been the working theories at the frontline of physics for over 30 years. Second, these theories appear to do away with the familiar conception of physical systems as aggregates of substantive individual particles. This conception was already undermined by Bose–Einstein and Fermi–Dirac statistics (§6.1.4), according to which the so-called particles cannot be assigned a definite trajectory in ordinary space. But quantum field theories go a long step further and—or so it would seem—conceive 'particles' as excitation modes of the field. This, I presume, motivated Howard Stein's saying that 'the quantum theory of fields is the contemporary locus of metaphysical research' (1970, p. 285). Finally, the very fact that physicists conspicuously and fruitfully resort to unperspicacious theories can teach us something about the aim and reach of science. Here is how physicists work, dirty-handed, in their everyday practice, a far cry from what is taught at the Sunday school of the 'scientific worldview' ".

[Kuhlmann-5] Meinard Kuhlmann, "Physicists debate whether the world is made of particles or fields—or something else entirely, Scientific American, 2013 Aug;309(2).

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