Abstract
According to Karl Popper, science cannot verify its theories empirically, but it can falsify them, and that suffices to account for scientific progress. For Popper, a law or theory remains a pure conjecture, probability equal to zero, however massively corroborated empirically it may be. But it does just seem to be the case that science does verify empirically laws and theories. We trust our lives to such verifications when we fly in aeroplanes, cross bridges and take modern medicines. We can do some justice to this apparent capacity of science to verify if we make a number of improvements to Popper’s philosophy of science. The key step is to recognize that physics, in accepting unified theories only, thereby makes a big metaphysical assumption about the nature of the universe. The outcome is a conception of scientific method which facilitates the criticism and improvement of metaphysical assumptions of physics. This view provides, not verification, but a perfect simulacrum of verification indistinguishable from the real thing.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
What do I mean by “verification”? I mean this: A theory verified by evidence is one sufficiently well supported by evidence to justify confidence that its standard empirical predictions, to standard degrees of accuracy, are true, this confidence being such that we are prepared to entrust our life to the correctness of these predictions (“p” is true iff p.) This way of construing “empirical verification” allows us to speak of verifying a physical theory even though we acknowledge that almost all precise physical theories are false. However, even in terms of this somewhat modest notion of verification, in the essay I argue that there is no such thing as the verification of theory by evidence. There is, at most, a simulacrum of verification of theory by evidence, not verification by evidence as such. If we were justified in holding that the metaphysical thesis of physicalism is true, then there would, on occasions, in appropriate circumstances, be authentic verification of a theory—one that is sufficiently empirically successful, and sufficiently in accord with physicalism. I shall argue that we have valid grounds for accepting physicalism as a part of scientific knowledge, but that does not extend to being justified in holding that physicalism is true. Physicalism is to be understood, here, as the thesis that the universe is such that all phenomena occur in accordance with a unified pattern of physical law. (What “unified” means in this context will be clarified as we proceed.)
See, however, Maxwell (2017a, especially ch. 9).
What follows is a much improved formulation of Hume’s problem of induction. I have formulated it in somewhat similar ways elsewhere: see Maxwell (2017a, 24–29; 2017b, 74–83). I repeat the argument here because (a) it is required for the argument of this paper, (b) it is of fundamental importance to the philosophy of science, and (c) it seems that it is not widely understood and appreciated by philosophers of science.
These considerations concerning empirically successful ad hoc theories may seem reminiscent of Goodman’s considerations concerning grue and bleen: see Goodman (1954). Actually, there is a substantial difference. For a critical discussion of Goodman, see Maxwell (1984, 2nd ed., 385–386; 1998, 155–157; 2004, 171–172; 2017a, 47–48; or 2017c, 137–138).
Discovering how to justify the rejection of these infinitely many empirically more successful ad hoc rival theories to any accepted physical theory is of course Hume’s problem of induction. The problem, as formulated here, is an intensification of Hume’s version of the problem. Hume considered the possibility that the laws of nature might abruptly change, but he did not consider the infinitely many different ad hoc theories that postulate such a change. He did not consider changes in the laws of nature that arise in connection with the variation of variables other than time—such as space, mass, temperature, and so on. And he did not consider the infinitely many ad hoc theories that are even more empirically successful than the physical theory that we accept.
Whenever philosophers discuss the thesis of uniformity, they tend to mean uniformity of the laws of nature with respect to time, or time and space. Uniformity with respect to other variables, such as mass, charge or temperature, tend to be ignored. Uniformity with respect to time and space is, however, insufficient; we require uniformity with respect to other variables as well, if we are to do justice to what goes in in practice in physics.
It may not be entirely clear as to what it is that this thesis of uniformity asserts, in the main because it may not be clear what it means to say of a theory that it is “ad hoc”. This issue will be clarified below.
Inductivists and confirmationists will object that any ad hoc theory that postulates an abrupt change in the laws of nature, however well it may fit available data, is to be rejected, not because it clashes with the uniformity thesis, but because it is inherently less verifiable than its non-ad hoc rival. This objection is rebutted below.
Popper held on to his principle of demarcation, and stressed its significance, throughout his career: see for example Popper (1983, 159–174).
LScD specifies another conception of simplicity, based on what Popper calls the “dimension” of a theory: given two theories, T1 and T2, if the number of basic statements required to refute T1 is greater than the number required to refute T2, then T2 is simpler than T1. Popper is emphatic, however, that if these two requirements of simplicity clash, the one that holds that the theory with the greater empirical content is the simpler is to be preferred (Popper 1959, chs. vi-vii). This accords with the basic theme of LScD: everything stems from falsifiability. We can, then, ignore Popper’s notion of simplicity based on the idea of “dimension”, and concentrate on the notion indicated in the text, based on the notion of the degree of falsifiability of a theory, or its empirical content.
Popper might declare that his methodology cannot be refuted because it is about what scientists ought to do, not what they in fact do: he almost says this in Horgan (2018). But that ignores that here we have a case where we would all agree, Popper included, that scientists very definitely ought not to do what falsificationism says they ought to do. Falsificationism is refuted by what scientists in fact do, and what everyone would agree they ought to do.
In any one domain, we retain that part of T required to predict the evolution of phenomena in that domain, and we discard any content of T that is not required. Any domain must include a range of phenomena, however small, to avoid the possibility that T acquires an especially simple form for an especially symmetric physical system.
For further developments of this account of theory unity, including an account of the role that symmetry principles play in it, see Maxwell (2017a, ch. 5 and appendix 1).
For references to rival proposals, and criticism of them, see note 14.
I have tried, again and again, to break down the dogmatic view that science does not make any metaphysical assumption about the nature of the universe: see Maxwell (1974; 1993; 1998; 2004; 2011; 2017a-c; 2019). So far, I have failed to make a dent in this dogmatic conviction. It might be thought, perhaps, that Kuhn (1962) and Lakatos (1970) both reject the dogmatic doctrine. Not so; both hold that “paradigms” or “hard cores” are accepted and rejected, ultimately, on empirical grounds: see Maxwell (1998, 40).
It might be interpreted, at one extreme of precision and content, to assert: the universe is such that any physical theory which shows any sign whatsoever of being slightly ad hoc, is false. In other words, it might be interpreted to assert: the universe is such that only a physical “theory of everything” that is perfectly unified is true. At the other extreme of imprecision and lack of content, it might be interpreted to assert: the universe is such that a physical theory that is ad hoc in space or time is false—but theories that are ad hoc in less extreme ways may well be true.
It is a platitude that this goes on at the experimental level. New knowledge leads to the development of new methods—new instruments, for example, such as the telescope or particle collider—which in turn lead to new knowledge. Because of the pernicious influence of standard empiricism, it is less widely appreciated that it goes on at the theoretical level as well (just as AOE says it should). A classic case in point is the way Einstein’s special theory of relativity becomes a methodological principle (an acceptable theory must be Lorentz’ invariant) which in turn contributes to the discovery and acceptance of major new physical theories, such as quantum electrodynamics and quantum chromodynamics.
For much more detailed expositions of, and arguments for, AOE, that have been progressively improved over the years, see works referred to in notes 25 and 27.
See Maxwell (1993, 275–305) for an account of Einstein’s exploitation of AOE in discovering special and general relativity. See Maxwell (2017b, ch. 5) for an account of how physics would have met with even greater success if it had implemented AOE explicitly over the centuries, undistracted by standard empiricism.
For a discussion of this issue see especially Maxwell (2017b, especially chs. 1, 2, and 5).
See Maxwell (2017a, ch. 9) for a more detailed exposition of this point.
A physical “theory of everything” is a fundamental physical theory that applies to all possible physical phenomena, and in principle—not, of course, in practice—predicts how phenomena evolve in time.
A false theory may, of course, make true approximate predictions. Thus Kepler’s laws make false precise predictions about planetary motions, but true approximate predictions.
See Maxwell (2017a, ch. 8 and appendix 2) for a more detailed exposition of this solution to the problem of verisimilitude. For a discussion of attempts to solve the problem of verisimilitude that do not employ the notions of “true theory of everything” and “approximate derivation” see Zwart and Franssen (2007).
These are somewhat idealized requirements for a theory to be accepted. In practice, the community of physicists may accept a new theory long before (1) has been established, on the basis of the conjecture that further scientific research will establish (1).
See Maxwell (2017a, ch. 5 and appendix 1).
References
Bartelborth, T. (2002). Explanatory unification. Synthese, 130, 91–107.
Einstein, A. (1982). Autobiographical notes. In P. A. Schilpp (Ed.), Albert Einstein: Philosopher-scientist. La Salle: Open Court.
Friedman, M. (1974). Explanation and scientific understanding. Journal of Philosophy, 71, 5–19.
Goodman, N. (1954). Fact, fiction and forecast. London: Athlone Press.
Harman, G. (1965). The inference to the best explanation. The Philosophical Review, 74, 88–95.
Horgan, J., 2018, The Paradox of Karl Popper, Scientific American, 22 August, 2018: https://blogs.scientificamerican.com/cross-check/the-paradox-of-karl-popper/.
Howson, C., & Urbach, P. (1993). Scientific reasoning: The bayesian approach. La Salle: Open Court.
Jeffreys H., & Wrinch, D. (1921). On certain fundamental principles of scientific enquiry. Philosophical Magazine, 42, 269–298.
Kitcher, P. (1981). Explanatory unification. Philosophy of Science, 48, 507–531.
Kitcher, P. (1989). Explanatory unification and causal structure. In P. Kitcher & W. Salmon (Eds.), Scientific explanation Minnesota Studies in the Philosophy of Science. Minneapolis: University of Minnesota Press.
Kuhn, T. S. (1962). The structure of scientific revolutions. Chicago: Chicago University Press.
Lakatos, I. (1970). Falsification and the methodology of scientific research programmes. In I. Lakatos & A. Musgrave (Eds.), Criticism and the growth of knowledge. Cambridge: Cambridge University Press.
Maxwell, N. (1972). A Critique of Popper’s views on scientific method. Philosophy of Science, 39, 131–152.
Maxwell, N. (1974). The rationality of scientific discovery. Philosophy of Science, 41, 123–153.
Maxwell, N. (1984). From knowledge to wisdom: A revolution in the aims and methods of science (2nd ed.). Oxford: Blackwell.
Maxwell, N. (1993). Induction and scientific realism: Einstein versus van Fraassen. British Journal for the Philosophy of Science, 44, 61–79.
Maxwell, N. (1998). The comprehensibility of the universe: A new conception of science. Oxford: Clarendon Press.
Maxwell, N. (2004). Is science neurotic? London: World Scientific.
Maxwell, N. (2011). A priori conjectures in physics. In M. Shaffer & M. Veber (Eds.), What place for the a priori? La Salle: Open Court.
Maxwell, N. (2014). How universities can help create a wiser world: The urgent need for an academic revolution. Exeter: Imprint Academic.
Maxwell, N. (2017a). Understanding scientific progress. St. Paul: Paragon House.
Maxwell, N. (2017b). In praise of natural philosophy: A revolution for thought and life. Montreal: McGill-Queen’s University Press.
Maxwell, N. (2017c). Karl Popper, science and enlightenment. London: UCL Press.
Maxwell, N. (2019). The metaphysics of science and aim-oriented empiricism. Cham: Springer.
Maxwell, N. (2020). Our fundamental problem: A revolutionary approach to philosophy. Montreal: McGill-Queen’s University Press.
Maxwell, N. (2021a). How Universities Have Betrayed Reason and Humanity—And What's to Be Done About It. 12 April, 2021. https://doi.org/10.3389/frsus.2021.631631.
Maxwell, N. (2021b). The world crisis – and what to do about Ii: A revolution for thought and action. London: World Scientific.
McAllister, J. (1996). Beauty and revolution in science. Ithaca: Cornell University Press.
Miller, D. (1974). Popper’s qualitative theory of verisimilitude. British Journal for the Philosophy of Science, 25, 166–177.
Newton-Smith, W. H. (1981). The rationality of science. London: Routledge and Kegan Paul.
Popper, K. (1959). The logic of scientific discovery. London: Hutchinson.
Popper, K. (1963). Conjectures and refutations. London: Routledge and Kegan Paul.
Popper, K. (1983). Realism and the aim of science. London: Hutchinson.
Reichenbach, H. (1961). Experience and prediction. Chicago: University of Chicago Press.
Schurz, G. (1999). Explanation as unification. Synthese, 120, 95–114.
Stove, D. (1982). Popper and after: Four modern irrationalists. Oxford: Pergamon Press.
Tichý, P. (1974). On Popper’s definition of verisimilitude. British Journal for the Philosophy of Science, 25, 155–160.
Watkins, J. (1984). Science and scepticism. Princeton: Princeton University Press.
Weber, E. (1999). Unification. Synthese, 118, 479–499.
Worrall, J. (1989). Why both Popper and Watkins fail to solve the problem of induction. In F. Dagostino, I. C. Jarvie, & J. Watkins (Eds.), Freedom and rationality. Dordrecht: Kluwer.
Zwart, D. S., & Franssen, M. (2007). An impossibility theorem for verisimilitude. Synthese, 158, 75–92.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Maxwell, N. Improve Popper and Procure a Perfect Simulacrum of Verification Indistinguishable from the Real Thing. J Gen Philos Sci 53, 163–185 (2022). https://doi.org/10.1007/s10838-021-09570-6
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10838-021-09570-6