Scientific realism

Can we claim to know anything about reality? Is it a goal of science to describe reality? Does science make any progress at describing reality? This outline focuses on the issues of metaphysical progress from science, while my outline on the scientific method discusses the epistemological foundations and limitations of science.

Issues and positions

Metaphysics

When one encounters the word “metaphysics”, what is usually meant is one of the three following ideas:

• What really exists, or at least what exist literally beyond what we know in physics. This is one of the oldest and fundamental branches in philosophy. In a naturalist sense, high-energy theoretical physics can be seen as examples of theoretical metaphysics at its best, ideas about about what there exists at a more fundamental level based on what we know at more pedestrian levels of experience.
• A pejorative word, denoting ideas that are meaningless because they are claims beyond what is verifiable. This was the view of the positivistists.
• A loosely, if ill-defined, woo-woo word in which a mystic, guru, or metaphysician may claim to specialize.

The word ‘metaphysics’ is derived from a collective title of the fourteen books by Aristotle that we currently think of as making up Aristotle’s Metaphysics. Aristotle himself did not know the word. (He had four names for the branch of philosophy that is the subject-matter of Metaphysics: ‘first philosophy’, ‘first science’, ‘wisdom’, and ‘theology’.) At least one hundred years after Aristotle’s death, an editor of his works (in all probability, Andronicus of Rhodes) titled those fourteen books “Ta meta ta phusika”—“the after the physicals” or “the ones after the physical ones”—the “physical ones” being the books contained in what we now call Aristotle’s Physics. The title was probably meant to warn students of Aristotle’s philosophy that they should attempt Metaphysics only after they had mastered “the physical ones”, the books about nature or the natural world.1

Stealing from encyclopedia.com:

In medieval and modern philosophy “metaphysics” has also been taken to mean the study of things transcending nature—that is, existing separately from nature and having more intrinsic reality and value than the things of nature—giving meta a philosophical meaning it did not have in classical Greek.

Especially since Immanuel Kant metaphysics has often meant a priori speculation on questions that cannot be answered by scientific observation and experiment. Popularly, “metaphysics” has meant anything abstruse and highly theoretical—a common eighteenth-century usage illustrated by David Hume’s occasional use of metaphysical to mean “excessively subtle”. The term has also been popularly associated with the spiritual, the religious, and even the occult. In modern philosophical usage metaphysics refers generally to the field of philosophy dealing with questions about the kinds of things there are and their modes of being. Its subject matter includes the concepts of existence, thing, property, event; the distinctions between particulars and universals, individuals and classes; the nature of relations, change, causation; and the nature of mind, matter, space, and time.

Realism and anti-realism

• Naive realism. Why would I doubt the world I see is real?
• Skepticism
• Descartes’ demon
• Putnam Brain in a vat2
• The Matrix
• Bostrom - The Simulation Argument
• Am I a more advanced civilization’s tamagotchi?
• Distinguish Anti-realism from non-realism

The world extended in space and time is but our representation.3

Humeanism

• laws of nature
• Humean vs Non-humean :: regularity vs necessitarianism
• Donald Davidson
• David Lewis and Humean supervenience:

Humean supervenience is named in honor of the greater denier of necessary connections. It is the doctrine that all there is to the world is a vast mosaic of local matters of particular fact, just one little thing and then another.4

• Emphasize the naturalist revolution within Humean views.
• See the outline on Naturalism.

Scientific realism

Some attempts at definitions:

Science makes real progress in describing real features of the world.

To a very rough, first approximation, realism is the view that our best scientific theories correctly describe both observable and unobservable parts of the world.5

Scientific realism is a positive epistemic attitude towards the content of our best theories and models, recommending belief in both observable and unobservable aspects of the world described by the sciences.6

• Boyd
• Sellars
• Chakravartty
• Psillos

Challenges to Scientific Realism:

• Underdetermination; language dependence; Duhem-Quine thesis; the problem of translation
• Positivism; Instrumentalism; linguistic frameworks; verificationism
• Kuhn, Lakatos, Laudan, Feyerabend
• Scientific revolution; paradigm shift; pessimistic meta-induction
• Social constructivism
• Epistemological anarchism
• TODO: work through the challenges presented in these videos.
• And this, this, and this.

At first blush it seems to us that the theories last only a day and that ruins upon ruins accumulate. Today the theories are born, tomorrow they are the fashion, the day after tomorrow they are classic, the fourth day they are superannuated, and the fifth they are forgotten.7

TODO: find the page number for above Poincaré quote.

Our arguments have to be about the world we experience, not about a world made of paper.8

As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.9

There is a difference, however, between working crossword puzzles and the pursuit of higher mathematics. In the case of mathematics, you don’t triumph over the capricious machinations of another human being (the designer of the puzzle) but, rather, over the absolute fabric of logical relations. The body of knowledge you have developed has the enviable characteristic of being demonstrably and absolutely true, given the set of assumptions (axioms) underlying your contemplations, irrespective of the foibles of your own human limitations, indeed, irrespective of the existence of humanity itself. And, as an added bonus, if it should so happen that the set of axioms on which your intellectual fortress is built is somehow relevant to the physical world, then you can even walk away with a deeper understanding of your natural surroundings. The wonder of group theory is that its relevance to the disciplines of both mathematics and natural science far exceeds the self-contained boundaries within which it was first developed.10

Instrumentalism

Theoretical concepts may have use in predicting observations, but we have no ontological commitments to them.

• anti-realist
• Duhem
• Wikipedia: “Initially a novel perspective introduced by Pierre Duhem in 1906, instrumentalism is largely the prevailing theory that underpins the practice of physicists today.”11
• Later Wittgenstein in PI. See Postpositivism, below.

Positivism

Verification theory of meaning: All statements that can’t be empirically verified are meaningless.

• anti-realist
• Auguste Comte
• Wittgenstein
• Wittgenstein (1922). Tractatus Logico-Philosophicus.
• Ernst Mach
• The Vienna Circle
• Ayer, Carnap, Neurath, Wittgenstein, Frege, von Neuman, Hilbert
• Ayer (1952). Language, Truth, and Logic.
• Hans Reichenbach (1891-1953) and the Berlin Circle
• International Encyclopedia of Unified Science
• verificationism, nominalism, quietism
• Gödel
• Russell,
• The Logical Structure of the World12
• Scheinproblem = Pseudo-problem
• The Logical Syntax of Language13
• Carnap’s “ESO”14
• Carnap’s “Logical Foundations of Science”15
• LSL in a nutshell16

Positivism is a philosophy of science and epistemology that roughly defends a qualified empiricism, that the scientific method is the only route to knowledge, and that all statements that cannot be empirically verified are meaningless. Positivism is strongly eliminative about metaphysics and claims that many metaphysical questions and positions are not open or false, but meaningless because of their lack of attachment to empirically demonstrable things or effects.

Russell:

Modern analytical empiricism […] differs from that of Locke, Berkeley, and Hume by its incorporation of mathematics and its development of a powerful logical technique. It is thus able, in regard to certain problems, to achieve definite answers, which have the quality of science rather than of philosophy. It has the advantage, in comparison with the philosophies of the system-builders, of being able to tackle its problems one at a time, instead of having to invent at one stroke a block theory of the whole universe. Its methods, in this respect, resemble those of science.17

Logical positivism: a form of positivism, developed by members of the Vienna Circle, that considers that the only meaningful philosophical problems are those that can be solved by logical analysis.

Note any differences between:

• positivism - Comte, Mach
• logical positivism - Vienna Circle
• logical empiricism - Reichenbach’s preferred term18, Berlin Circle

This means that positivism is generally seen to imply anti-realist views of science and mathematics, preferring as Carnap says in Empiricism, Semantics, and Ontology:

Empiricists are in general rather suspicious with respect to any kind of abstract entities like properties, classes, relations, numbers, propositions, etc. They usually feel much more in sympathy with nominalists than with realists (in the medieval sense). As far as possible they try to avoid any reference to abstract entities and to restrict themselves to what is sometimes called a nominalistic language, i.e., one not containing such references.19

Positivists have instrumentalist (anti-realist) views about the models science produces, given that they are constructed from abstractions and involve the epistemological limitations of induction and theory change. As a qualified sort of empiricism that supports the primacy of the scientific method, positivism is sometimes equated with scientism (often derogatorily) if one takes it to claim that science is the only way to attain knowledge.

In a more general sense, positivism is aligned with naturalism, the meta-philosophy that roughly says that science should inform and bootstrap our philosophical claims. Naturalists, having a more broadly aligned and various support for science, may not have such exclusive views of epistemology or such eliminative views of metaphysics. Many naturalists are instead realists about science, math, and/or ethics, for example following a version of structural realism about the discoveries from science, capturing and constraining real structures in nature.

Postpositivism

A metatheoretical stance that critiques and amends positivism. While positivists believe that the researcher and the researched person are independent of each other, postpositivists accept that theories, background, knowledge and values of the researcher can influence what is observed. They believe that human knowledge is based not on unchallengeable, rock-solid foundations, but rather upon human conjectures.

• Karl Popper (1902-1994)
• falsifiability over verifiability
• a turn towards realism
• Popper alleged that instrumentalism reduces basic science to what is merely applied science.
• Willard Van Orman Quine (1908-2000)
• Quine’s “Two Dogmas”20
1. analytic-synthetic distinction
2. reductionism (verification theory of meaning)
• Duhem-Quine thesis
• inscrutability of reference
• Thomas Kuhn (1922-1996)

Instrumentalism can be formulated as the thesis that scientific theories—the theories of the so-called ‘pure’ sciences—are nothing but computational rules (or inference rules); of the same character, fundamentally, as the computation rules of the so-called ‘applied’ sciences. (One might even formulate it as the thesis that “pure” science is a misnomer, and that all science is ‘applied’.) Now my reply to instrumentalism consists in showing that there are profound differences between “pure” theories and technological computation rules, and that instrumentalism can give a perfect description of these rules but is quite unable to account for the difference between them and the theories.21

The “death” of positivism:

• anti-positivism, post-structuralism, postmodernism (continental)

Later Wittgenstein:

• Wittgenstein (2009). Philosophical Investigations.
• Ordinary language philosophy
• Instrumentalist and somewhat pragmatist
• An imprtant project is to understand the differences between early (TLP) and late (PI) Wittgenstein. It is quite the about-face.
• TLP: Language has a structure that can be mapped onto (meaning) the logical structure of the world
• PI: The meaning of a word is its use.

Wittgenstein in PI:

Philosophy is a battle against the bewitchment of our intelligence by means of our language.

Pragmatism

• anti-realist
• Charles Sanders Peirce (1839-1914)
• William James (1842-1910)
• John Dewey (1859-1952)
• later Wittgenstein
• Rorty and Putnam
• Quine
• Dennett
• Our confidence comes in continuous amounts. We might as well act as if a claim with a certain confidence is real, however, we really deny realism.
• Meaning is rooted in use.
• Uniquely American philosophical movement.

Postmodernism

• anti-realist, relativism
• Incommensurability
• Conventionalism
• Postmodernism
• Jean-François Lyotard (1924-1998)
• Gilles Deleuze (1925-1995)
• Michel Foucault (1926-1984)
• Jacques Derrida (1930-2004)
• Social constructivism
• Thomas Kuhn (1922-1996)
• Imre Lakatos (1922-1974)
• Paul Feyerabend (1924-1994)
• Larry Laudan (b. 1941)
• Epistemological anarchism
• How French “intellectuals” ruined the West: postmodernism and its impact, explained
• Ryan: Resonating, going viral, does not indicate that it’s true or good for progress.
• Ryan: I’ve been wanting to write an essay in this vein for years, and this author is better equipped to explain postmodernism than I. This argument could still be further buttressed with a brief history of the Enlightenment carrying empiricism and liberalism. Today there are still empiricist / naturalist / structuralist / realist / pragmatist ways of viewing the world that reject relativism and recognize some objectivity in the truth of claims about the world, be them descriptive or normative. There are better more accurate ways of describing the world and what one should do than others.
• Ryan: It also irritates me that so many people are introduced to continental philosophy, including postmodernism, as if that’s the end of philosophy.
• Explaining Postmodernism In 2018 - Stephen Hicks

Constructive empiricism

Science aims to give us theories that are empirically adequate, but does not justify metaphysical claims about reality.

• anti-realist
• van Fraassen, Bueno
• van Fraassen’s “Arguments Concerning Scientific Realism”22
• Unlike positivism/instrumentalism, theories should be taken literally.
• Healey criticizes van Fraassen’s CE23

Structural realism

Science has identified real patterns, relationships, and structures (at least within a regime) in nature.

• realist
• early Wittgenstein: picture theory of language/meaning
• strucuturalism more generally and structural anthropology: Claude Lévi-Strauss
• Henri Poincaré
• John Worrall
• Ladyman, French, Psillos, Votsis, Devitt, Frigg
• Epistemic Structural Realism (ESR)
• Ontic Structural Realism (OSR)
• Every Thing Must Go24
• How science tracks truth25
• Everything you always wanted to know about structural realism but were afraid to ask26
• Scientific Metaphysics27
• contrast with Bueno’s structural empiricism

[W]hat is objective must be common to many minds and consequently transmissible from one to the other. … [P]ure quality … is intransmissible… . But it is not the same with relations… From this point of view, what is objective is … only pure relation.28

TODO: find the page number for above Poincaré quote. I found the above quotes in a talk by Arthur Fine: Structural Realism, Then & Now.

Feminist epistemology

• Situated knowers
• Feminist standpoint theory

Critical realism

Critical realists believe that there are unobservable events which cause the observable ones; as such, the social world can be understood only if people understand the structures that generate such unobservable events.

• realist
• Roy Wood Sellars, Wilfrid Sellars
• Freely emphasizes the political implications of scientific realism.
• The normative importance of climate science.

• Hasok Change

My thoughts

Here, I plan to summarize my thoughts after finishing the analysis of several sources below.

Ways to phrase the issue:

• Does your worldview have commitments to ontologies claimed to be part of reality?
• Is the goal of science to describe reality? Does science make any progress at that?

Misc.:

• Relation to naturalism and mathematical realism.
• We should remind ourselves that independent of our debate, the world is doing something in certain ways and not in others.

Questions:

• Is there a position that requires any element of a good scientific theory to be interpretable? What would that mean?
• Maybe scientism is really the same thing positivism re-branded; similarly, naturalism is empiricism re-branded.

My defense of realism

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Annotated bibliography

• TODO

• TODO

Moore, G.E. (1925). A Defense of Common Sense.

• “Here is one hand.”
• TODO

• TODO

Carnap, R. (1928). The Logical Structure of the World and Pseudoproblems in Philosophy.

• Der logische Aufbau der Welt
• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

Carnap, R. (1950). Empiricism, Semantics, and Ontology.

• Carnap (1950)

1. The problem of abstract entities

• Empiricists tend to prefer to restrict themselves to nominalistic language – without containing references to abstract entities.
• Formalists view mathematics as a mechanistic calculus without interpretation, but physics seems to lend its own interpretation.

In physics it is more difficult to shun the suspected entities because the language of physics serves for the communication of reports and predictions and hence cannot be taken as a mere calculus.

• A physicist may declare some parts of a theory as uninterpretable.
• Carnap says his purpose is to clarify that empiricists can accept a language referring to abstract entities without embracing platonic ontologies.

2. Linguistic frameworks

• Carnap defines linguistic frameworks, internal vs external questions (internal to the framework or about the metaphysical world), and the world of things.

To recognize something as a real thing or event means to succeed in incorporating it into the system of things at a particular space-time position so that it fits together with the other things as real, according to the rules of the framework.

• Carnap distinguishes that only the philosopher (not the man on the street nor the scientist) asks the external questions about reality outside the linguistic framework.
• Carnap goes on about what it means to accept the thing language. The system can be constructed by introducing new language expressions (as a sequence of typedefs, as he seems to mean).

My thoughts

• Sometimes I feel like Carnap repeats his theses though as if that helps support them. He says over and over that accepting a thing in a language is practical matter, not a theoretical/metaphysical one, which I agree with to a degree. But then that leaves us on the edge of a lot of semantic cliffs, saying “but what do our abstract entities mean?”, or rather, “what does their scientific success mean?”.
• In the end, my impression is that I’m still not satisfied with nominalism. I feel like the road to addressing Carnap, the issues he should have acknowledged, is that some of our abstract classes are super fucking natural. The success of some instances of our abstract internal languages should lead one, through the same methods of scientific inference that we do within the internal language, to do abduction to natural kinds in the external world. To deny the likely success of that abduction is to plead that there is a conspiracy.

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

• TODO

van Fraassen, B. (1980). The Scientific Image.

“Arguments Concerning Scientific Realism”

• TODO

• TODO

• TODO

Putnam, H. (1981). Reason, Truth, and History.

• Brain in a vat thought experiment.
• TODO

My thoughts

• TODO

• Putnam, H. (1982). Three Kinds of Scientific Realism.
• Fine, A. (1984). The Natural Ontological Attitude.
• Fine, A. (1984). And Not Anti-Realism Either.
• Musgrave, A. (1989). Noah’s Ark Fine for Realism.
• Worrall, J. (1989). Structural Realism: The Best of Both Worlds?
• Laudan, L. (1990). Demystifying Underdetermination.
• Dennett, D. (1991). Real Patterns.
• Ladyman, J. (1998). What is Structural Realism?
• Bueno, O. (1999). What is Structural Empiricism?
• Psillos, S. (1999). Scientific Realism: How Science Tracks Truth.
• Psillos, S. (2000). The Present State of the Scientific Realism Debate.
• Chang, H. (2001). Realism Beyond Footstamping.
• van Fraassen, B. (2001). Constructive Empiricism Now.
• Hacking, I. (2006). Natural Kinds.
• Chakravartty, A. (2007). A Metaphysics for Scientific Realism.
• Psillos, S. (2007). Choosing the Realist Framework.
• Bueno, O. (2008). Structural Realism, Scientific Change, and Partial Structures.
• Bain, J. (2009). Towards Structural Realism.
• Ladyman, J. & Ross, D. (2009). Every Thing Must Go: Metaphysics Naturalized.
• Psillos, S. (2009). On Reichenbach’s argument for scientific realism.
• Psillos, S. (2010). Scientific Realism: Between Platonism and Nominalism.
• Frigg, R. & Votsis, I. (2011). Everything You Always Wanted to Know About Structural Realism But Were Afraid to Ask.
• French, S. & Ladyman, J. (2011). In Defense of Ontic Structural Realism.
• Mizrahi, M. (2012). Pessimistic Induction: A Bad Argument Gone Too Far.
• Psillos, S. (2012). One Cannot Be a Little Bit Realist: Putnam and van Fraassen.
• Landry, E. & Rickles, D. (2012). Structural Realism.
• Ross, D., Ladyman, J., & Kincaid, H. (2013). Scientific Metaphysics.
• French, S. (2014). The Structure of the World: Metaphysics and Representation.
• Tegmark, M. (2014). Our Mathematical Universe: My Quest for the Ultimate Nature of Reality.

References

Ayer, A. J. (1952). Language, truth and logic (2nd ed.). Dover Publications. (Originally published in 1946).

Carnap, R. (1937). Logical Syntax of Language. Kegan Paul, Trench, Trubner & Co.

———. (1950). Empiricism, semantics, and ontology. Revue Internationale de Philosophie, 4, 20–40.

———. (1955). The logical foundations of the unity of science. In International Encyclopedia of Unified Science: Volume I. University of Chicago Press, 42–62.

———. (2003). The Logical Structure of the World. (R. George, Trans.). Chicago: Open Court. (Originally published in 1928 as Der logische Aufbau der Welt).

Chakravartty, A. (2007). A Metaphysics for Scientific Realism. Cambridge University Press.

———. (2011). Scientific realism. Stanford Encyclopedia of Philosophy. http://plato.stanford.edu/entries/scientific-realism/

Einstein, A. (1922). Geometry and Experience. London: Methuen & Co. Address given to the Prussian Academy of Sciences on January 27, 1921. http://www-history.mcs.st-andrews.ac.uk/Extras/Einstein_geometry.html

Fowler, S. (2010). LSL in a nutshell. https://philarchive.org/archive/FOWLIA

Frigg, R. & Votsis, I. (2011). Everything you always wanted to know about structural realism but were afraid to ask. European Journal for Philosophy of Science, 1, 227–276.

Healey, R. (2007). Gauging What’s Real. Oxford University Press.

Ladyman, J., Ross, D., Spurrett, D., & Collier, J. (2007). Every Thing Must Go: Metaphysics Naturalised. Oxford University Press.

Lewis, D. (1986). Philosophical Papers II. Oxford University Press.

Poincaré, H. (2014). The Foundations of Science: Science and hypothesis, the value of science, science and method. (G. Halstead, Trans.). Cambridge: Cambridge University Press. (Originally published in 1905).

Popper, K. (1963). Conjectures and Refutations: The Growth of Scientific Knowledge. Routledge.

Psillos, S. (1999). Scientific Realism: How Science Tracks Truth. London, New York: Routledge.

Putnam, H. (1981). Reason, Truth, and History. Cambridge University Press.

Quine, W. V. O. (1951). Two Dogmas of Empiricism. The Philosophical Review, 60, 20–43.

Ross, D., Ladyman, J., & Kincaid, H. (2013). Scientific Metaphysics. Oxford University Press.

Rovelli, C. (2003). A dialog on quantum gravity. https://arxiv.org/abs/hep-th/0310077

Russell, B. (1945). A History of Western Philosophy. Simon & Schuster.

Schumm, B. A. (2004). Deep Down Things. Johns Hopkins University Press.

Torretti, R. (1999). The Philosophy of Physics. Cambridge University Press.

van Fraassen, B. (1980). The Scientific Image. Oxford University Press.

van Inwagen, P. (2014). Metaphysics. Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/metaphysics/

Wittgenstein, L. (1922). Tractatus Logico-Philosophicus. (C. K. Ogden, Trans.). London: Kegan Paul, Trench, Trubner & Co.

———. (2009). Philosophical Investigations. (E. Anscombe & P. Hacker, Trans., P. Hacker & J. Schulte, Eds.) (4th ed.). Wiley-Blackwell. (Originally published in 1953).

1. van Inwagen (2014).

2. Putnam (1981).

3. Schrödinger quoting Schopenhauer in “Mind and Matter”.

4. Lewis (1986), p. ix.

5. Chakravartty (2007).

6. Chakravartty (2011).

7. Poincaré (2014).

8. Rovelli (2003), p. 5.

9. Einstein (1922).

10. Schumm (2004), p. 144.

11. Torretti (1999)’, p. 242–243.

12. Carnap (2003).

13. Carnap (1937).

14. Carnap (1950).

15. Carnap (1955).

16. Fowler (2010).

17. Russell (1945), p. 834.

18. Carnap (1950), p. 1.

19. Quine (1951).

20. Popper (1963), p. XXX.

21. van Fraassen (1980).

22. Healey (2007), p. 114–116.

23. Ladyman, Ross, Spurrett, & Collier (2007).

24. Psillos (1999).

25. Frigg & Votsis (2011).

26. Ross, Ladyman, & Kincaid (2013).

27. Poincaré (2014).