It is often claimed that the Duhem problem shows that the notion of falsifiability is inapplicable to scientific theories. I explain why the claim is false.

Popper argued that a statistical falsification required a prior methodological decision to regard sufficiently improbable events as ruled out. That suggestion has generated a number of fruitful approaches, but also a number of apparent paradoxes and ultimately, no clear consensus. It is still commonly claimed that, since random samples are logically consistent with all the statistical hypotheses on the table, falsification simply does not apply in realistic statistical settings. We claim that the situation is considerably improved if we ask a (...) conceptually prior question: when should a statistical hypothesis be regarded as falsifiable. To that end we propose several different notions of statistical falsifiability and prove that, whichever definition we prefer, the same hypotheses turn out to be falsifiable. That shows that statistical falsifiability enjoys a kind of conceptual robustness. These notions of statistical falsifiability are arrived at by proposing statistical analogues to intuitive properties enjoyed by exemplary falsifiable hypotheses familiar from classical philosophy of science. That demonstrates that, to a large extent, this philosophical tradition was on the right conceptual track. Finally, we demonstrate that, under weak assumptions, the statistically falsifiable hypotheses correspond precisely to the closed sets in a standard topology on probability measures. That means that standard techniques from statistics and measure theory can be used to determine exactly which hypotheses are statistically falsifiable. In other words: the proposed notion of statistical falsifiability both answers to our conceptual demands and submits to standard mathematical techniques. (shrink)

In an article in a previous issue of this journal, I argue against the falsity criterion in the definition of delusion by presenting cases of delusions that are not false. I thank José Eduardo Porcher for his thought-provoking reply to my article. Although Porcher agrees that the falsity criterion is incorrect, he argues that my method of showing this is unsatisfactory on the grounds that it relies on a pre-defined conception of delusion.

Many philosophers have asserted that evolutionary theory is unfalsifiable. In this paper I refute these assertions by detailing some falsifiable predictions of the theory and the evidence used to test them. I then analyze both these predictions and evidence cited to support assertions of unfalsifiability in order to show both what type of predictions are possible and why it has been so difficult to spot them. The conclusion is that the apparent logical peculiarity of evolutionary theory is not a property (...) of evolutionary theory; it is a property of our human-sized perspective on evolutionary theory. (shrink)

First, a brief history is provided of Popper's views on the status of evolutionary biology as a science. The views of some prominent biologists are then canvassed on the matter of falsifiability and its relation to evolutionary biology. Following that, I argue that Popper's programme of falsifiability does indeed exclude evolutionary biology from within the circumference of genuine science, that Popper's programme is fundamentally incoherent, and that the correction of this incoherence results in a greatly expanded and much (...) more realistic concept of what is empirical, resulting in the inclusion of evolutionary biology. Finally, this expanded concept of empirical is applied to two particular problems in evolutionary biology — viz., the species problem and the debate over the theory of punctuated equilibria — and it is argued that both of them are still mainly metaphysical. (shrink)

Modern (theoretical) physics seems to be in deep crisis today as many of its core aspects are not empirically well-confirmed. Heated exchanges among physicists on the scientific status of physical theories with little or, at best, a tenuous connection to possible experimental tests is highly visible in the popular scientific literature. Some physicists (e.g., Carroll 2014, 2019; Ijjas et al., 2017) argue that science must discard empirical testability as one of its defining properties and the highly explanatory theories of present-day (...) physics should be exempted from experimental testing, while others (e.g., Ellis & Silk 2014) spot in these arguments (for softening the testability or falsifiability requirement for modern physics) a dangerous tendency to undermine science. The philosopher of science who naturally draws most attention in these current debates is Karl Popper (1902-1994). His views, however, are often misrepresented in these debates. The prime objective of this paper is to explain how a more enlightened perspective on the ongoing debates can be obtained by a careful scrutiny of the Popperian criterion of falsifiability. As a first step in achieving this objective we will analyze the two major (conceptual) failures on which the current controversies rest. Our next step will be examining the controversial string theory to see whether the criteria of falsifiability is a ‘blunt instrument’ for determining its scientific status. (shrink)

The falsifiability debate has developed largely in response to a challenge offered in the name of this principle by Antony Flew. His basic contention is that since the assertion of any state of affairs is logically equivalent to a denial of its negation, it must always be possible to designate an actual or possible state of affairs which would "count against" or falsify the original assertion. "And," he concludes, "if there is nothing which a putative assertion denies then there (...) is nothing which it asserts either: and so it is not really an assertion." Hence, if the theologian wishes to claim that a typical "theological utterance" such as our suggested paradigm, is a genuine assertion, he must be prepared to stipulate what conceivable occurrence would falsify it. (shrink)

This entry gives an account of falsifiability both as championed in particular by Karl Popper and also more generally and examines its wider implications for scientific methodology.

One of the most focused research programs in the science-religion dialogue that has taken place up to the present is the series of volumes published jointly by the Vatican Observatory and the Center for Theology and the Natural Sciences. Originating with the encouragement of Pope John Paul II, this series has produced seven volumes focusing on how divine action can be understood in light of contemporary science. A retrospective volume published in 2008, Scientific Perspectives on Divine Action: Twenty Years of (...) Challenge and Progress, contains articles reviewing the series as a whole. In this article I analyze the series as a whole as well as some of the pivotal problems discussed throughout the series, such as the zero-sum game, scientific “traction,” falsifiability in theories of divine action, and locating special divine action in the physical world. (shrink)

Generic stereotypes are generically formulated generalizations that express a stereotype, like “Mexican immigrants are rapists” and “Muslims are terrorists.” Stereotypes like these are offensive and should not be asserted by anyone. Yet when someone does assert a sentence like this in a conversation, it is surprisingly difficult to successfully rebut it. The meaning of generic sentences is such that they can be true in several different ways. As a result, a speaker who is challenged after asserting a generic stereotype can (...) often simply dismiss the objection and maintain that the stereotype is true in a way that is compatible with the challenger’s objection. In this paper, a semantic theory for generics is presented that accounts for this type of defensive shifting in upholding generic stereotypes. This theory is then used to develop two strategies to object more efficiently. The first strategy is to immediately deny that either of the two possible ways in which a generic can be true obtains. The second strategy is to deny the satisfaction of an additional condition that is necessary for a generic sentence to be true. (shrink)

I highlight a category of experiment-what I am calling 'demonstrations'-that differs in justificatory mode and argumentative role from the more familiar 'crucial tests'. 'Tests' are constructed such that alternative results are equally and symmetrically informative; they help discriminate between alternative solutions within a problem-field, where questions are shared. 'Demonstrations' are notably asymmetrical (for example, "failures" are often not telling), yet they are effective, if not "crucial," in interparadigm dispute, to legitimate questions themselves. The Ox-Phos Controversy in bioenergetics serves as an (...) integral case study. (shrink)

« Si la connaissance se donne comme connaissance de la vérité, c’est qu’elle produit la vérité par le jeu d’une falsification première et toujours reconduite qui pose la distinction du vrai et du faux. » Leçons sur la volonté de savoir, Gallimard-Seuil, Paris, 2011 (1re éd. : 1971)."If knowledge is given as knowledge of the truth, it is because it produces the truth by the game of a first, primary falsification renewed again and again which raises the distinction of true (...) and false" [my translation]. Michel Foucault, Lessons on the will to know, Gallimard-Seuil, Paris, 2011 (1st ed.: 1971)I wonder how can Foucault, who refers to Nietzsche as source of inspiration, speak of falsification and deny at the same time objectivity of truth – besides the obvious pun. The challenge of Nietzsche is to contest the objectivity of truth as human desiderata, in such a context Foucault's notion of falsification (of what? falsification of an objective reality?) does either make no sense at all or encodes some other meaning beyond being false – a possible reading would be to take it that Foucault means "distortion", or better “will to deceive “.Perhaps, Foucault's observation amounts to the simple remark that some of the so-called scientific justifications of institutionalized qualifications and anathemas that have important political and socio-economic consequences such as those involving notions as health, disease, or gender do not have the scientific backing they are purported to have (now scientific backing, I guess, must be understood in a rather standard or naïve sense of distinguishing between sciences and pseudo-sciences). This might in some sense be a sensible reflection, and it must be conceded that Foucault had the merit of undertaking extensive and thorough examinations of archives, protocols and reports buried in institutions of various kinds which animated his legendary charming style of writing. Of course, this is quite far away from constituting a revolutionary assault on the notions of (scientific) truth, knowledge and meaning, but, one can say, I think, that his work motivated and still motivates some new approaches to the study of institutional archives. If the reading proposed in the preceding paragraph seems a too meagre result and we are prepared to read Foucault's remarks as involving more thorny epistemological matters, there are of course other ways to delve into them: On one hand I allow me to suggest studying the sceptics of the ancient Greek tradition, or the study of analogical dialectical reasoning within the Arabic Jurisprudence theories of the Middle-Ages (or more generally their theory of Argumentation that has been largely ignored also by the analytic approaches to Argumentation theory and Epistemic Logic), or if one dares to go so far the millenary Jain epistemological lessons on the Art of the Point of View provide plenty to learn from (this constitutes another gap in the recent studies on reasoning and knowledge). On the other one cannot escape the feeling that claims as those of Foucault, though they might be seen as involving interesting questions, many of them have been brought forward without awareness (or perhaps even because of lack of awareness) of the discussions that took place in depth and length in philosophy of logic and knowledge – moreover, as a quick look on nowadays publications bring to the fore, such kind of discussions are nowadays experiencing a creative impulse at a breath-taking pace (particularly so in the context of social sciences). True, analytic philosophers and some philosophers of logic stemming from analytic philosophy quite often ignore history of philosophy or even the history of the science they are purported to study, or more generally philosophical approaches foreign to their own framework – with the result that quite often they produced a rather superficial analysis of the links between knowledge and truth – however, this only points out, that it is time that we start learning each from the other Am I falsifying Foucault? Who knows …. (shrink)

In its 2018 global study on occupational fraud, the Association of Certified Fraud Examiners found asset misappropriation the most common category of fraud with expense reimbursement schemes the most frequent and costly form of misappropriation. In this case, Cassandra, a valued junior attorney on track to become a partner at her law firm, is strongly encouraged by a supportive senior attorney to join him in ordering an after-hours meal in clear violation of the firm's meal expensing policy. While Cassandra recognizes (...) that taking such action would be wrong, she is unclear what to do next. Sometimes the desire to do the right thing is fraught with complexities about the right thing to do. The purpose of the case is for students to examine the competing interests Cassandra faces in relation to the responsibilities she owes to her employer, colleagues, clients, profession, and herself. (shrink)

This is a response to a claim by Sven Ove Hansson to the effect that Poppers dictum that falsification lies at the heart of all pursuit of science has once and for all been falsified by his study of articles published in Nature during the year 2000. We claim that this is based on a misunderstanding of Poppers philosophy of science interpreting it too literally, and that alternative readings of those papers are fully compliant with falsification. We scrutinize Hansson’s arguments (...) as well as giving an overview of Poppers falsification theory. (shrink)

Cosmological models that invoke a multiverse - a collection of unobservable regions of space where conditions are very different from the region around us - are controversial, on the grounds that unobservable phenomena shouldn't play a crucial role in legitimate scientific theories. I argue that the way we evaluate multiverse models is precisely the same as the way we evaluate any other models, on the basis of abduction, Bayesian inference, and empirical success. There is no scientifically respectable way to do (...) cosmology without taking into account different possibilities for what the universe might be like outside our horizon. Multiverse theories are utterly conventionally scientific, even if evaluating them can be difficult in practice. (shrink)

:We propose to strengthen Popper’s notion of falsifiability by adding the requirement that when an observation is inconsistent with a theory, there must be a ‘short proof’ of this inconsistency. We model the concept of a short proof using tools from computational complexity, and provide some examples of economic theories that are falsifiable in the usual sense but not with this additional requirement. We consider several variants of the definition of ‘short proof’ and several assumptions about the difficulty of (...) computation, and study their different implications on the falsifiability of theories. (shrink)

A conceptual analysis of falsificationism is performed, in which the central falsificationist thesis is divided into several components. Furthermore, an empirical study of falsification in science is reported, based on the 70 scientific contributions that were published as articles in Nature in 2000. Only one of these articles conformed to the falsificationist recipe for successful science, namely the falsification of a hypothesis that is more accessible to falsification than to verification. It is argued that falsificationism relies on an incorrect view (...) of the nature of scientific inquiry and that it is, therefore, not a tenable research methodology. (shrink)

Coming from a mathematical background, I was always puzzled by Popper’s view, according to which, after the falsification of a scientific theory its degree of corroboration becomes zero. Most of the scientific theories taught in the physics departments have already been falsified, and what is the point of teaching theories, whose degree of corroboration is zero? The first important observation to make is that not all cases of falsification are the same. In some cases, as for instance in the case (...) of the theory of phlogiston, the falsification happened in agreement with the Popperian picture. Scientists discarded the falsified theory and opted for its alternative. Therefore, nowadays nobody tries to make a scientific contribution to the theory of phlogiston. Nevertheless, there are cases, and Newtonian mechanics is surely the most important among them, when the behaviour of the scientists after the falsification of the theory is from the Popperian point of view incomprehensible. Many scientists were not ready to discard the falsified theory, and not for irrational reasons. Some of the deepest discoveries in Newtonian mechanics as for instance the famous Kolmogorov, Arnold, Moser theorem were made many years after this theory was falsified. I think that Andrej Kolmogorov, Vladimir Arnold or Jürgen Moser cannot be compared to an Aristotelian philosopher, who adheres to his pet theory after its falsification. What these three mathematicians did was a fundamental contribution to modern science. (shrink)

Popper Proposed the criterion of falsifiability as a solution to the problem of demarcation i.e. of distinguishing science from pseudo-science and not, as many of his contemporaries in the Vienna Circle mistook it to be, a solution to the quite different problem with which they themselves were preoccupied, viz. of providing a criterion of meaning to distinguish the meaningful from the meaningless. While the positivists were concerned to damn metaphysics and exalt science, by identifying the empirically verifiable with the (...) meaningful, Popper was concerned to separate science from scientism, to damn astrology and to extol astronomy. In other words his preoccupation belongs not to the philosophy of language but to the philosophy of science. (shrink)

I identify a class of arguments against multiple realization (MR): BookofSand arguments. The arguments are in their general form successful under reasonably uncontroversial assumptions, but this, on the other hand, turns the table on identity theory: If arguments from MR can always be refuted by BookofSand arguments, is identity theory falsifiable? In the absence of operational demarcation criteria, it is not. I suggest a parameterized formal demarcation principle for brain state/process types and show how it can be used to identify (...) previously unconsidered contenders for evidence for MR, e.g., binary classification, division, and sorting. For these to be actual instances of MR, the corresponding psychological kinds must be verifiably, relevantly similar. I also briefly discuss possible linguistic, behavioral, and experimental demarcation criteria for psychological kinds. (shrink)

In this paper, we take a fresh look at three Popperian concepts: riskiness, falsifiability, and truthlikeness of scientific hypotheses or theories. First, we make explicit the dimensions that underlie the notion of riskiness. Secondly, we examine if and how degrees of falsifiability can be defined, and how they are related to various dimensions of the concept of riskiness as well as the experimental context. Thirdly, we consider the relation of riskiness to truthlikeness. Throughout, we pay special attention to (...) probabilistic theories and we offer a tentative, quantitative account of verisimilitude for probabilistic theories. (shrink)

The recent publication of The Logic of Scientific Discovery makes available for the first time an English translation of Popper’s Logik der Forschung. Numerous footnotes and 155 pages of new appendices have been added to the original text. However, the original text itself has been left unchanged. For an elaboration of many of the points sketched in the new material the author refers to a forthcoming sequel to this volume, Postscript: After Twenty Years.

Prompted by the "Panel Discussion of Grünbaum's Philosophy of Science" (Philosophy of Science 36, December, 1969) and other recent literature, this essay ranges over major issues in the philosophy of space, time and space-time as well as over problems in the logic of ascertaining the falsity of a scientific hypothesis. The author's philosophy of geometry has recently been challenged along three main distinct lines as follows: (i) The Panel article by G. J. Massey calls for a more precise and more (...) coherent account of the Riemannian conception of an intrinsic as opposed to an extrinsic metric, which the author has invoked as his basis for the distinction between non-conventional and convention-laden ascriptions of metrical equality and inequality; (ii) the latter distinction has been claimed to suffer from the liabilities of the so-called "standard conception" of scientific theories [36]; and (iii) pursuant to H. Putnam's "An Examination of Grünbaum's Philosophy of Geometry" [56], J. Earman [16, 17] and R. Swinburne [65] have contended that the difference between intrinsic and extrinsic metrics is scientifically unilluminating, and that the associated distinction between non-conventional and convention-laden metrical comparisons does not have the kind of relevance to extant scientific theories that the author has claimed for it. The essay consists of two installments. The present installment, comprising the Introduction and Part A, is devoted to the clarification, correction and further development of the author's prior writings on the philosophy of geometry. Its main objective is constructive elaboration rather than offering polemics. But rebuttals to Earman, [16, 17], Swinburne [65] and Demopoulos [13] are included, because their inclusion conduced to clarity in giving the new exposition. Part B is to appear in a subsequent issue and will be devoted to replies to critiques contained in the Panel Discussion and in other recent literature. It will range over issues in the philosophy of geometry and in the logic of ascertaining the falsity of a scientific hypothesis. By way of merely elliptical anticipation of much more precise statements given in Part A, section 3(ii), the Introduction dissociates the notion of convention-ladenness developed in Part A from the quite different notion integral to the so-called "standard conception" of scientific theories. Thereby, the Introduction prepares the ground for seeing, as a corollary to Part A, section 3(ii), that the notion advocated in the present essay has nothing to fear from the following fact, noted by C. G. Hempel ([36]; cf. also his 1970 Carus Lectures): "even though a sentence may originally be introduced as true by stipulation, it soon joins the club of all other member-statements of the theory and becomes subject to revision in response to further empirical findings and theoretical developments." Part A, which begins with a fairly detailed table of contents, endeavors to meet the aforementioned three-fold challenge to the author's philosophy of geometry. Massey's call for the provision of clear and detailed characterizations of intrinsic and extrinsic metrics is answered with the invaluable aid rendered personally by Massey himself. These characterizations are shown to permit a precise explication of the portions of Riemann's Inaugural Dissertation relevant to (1) Riemann's brilliant anticipation of Einstein's dynamical conception of physical geometry, and (2) the author's philosophical characterization of the metrics and geometries of space, time, and space-time {section 2(c)}. A byproduct of the analysis is to raise two major philosophical doubts concerning Clifford's sketch of a so-called "space-theory of matter" as elaborated in J. A. Wheeler's relativistic geometrodynamics. That theory's vision of understanding matter as a manifestation of empty curved space is questioned in regard to (1) the existence of an intra-geometrodynamic basis for individuating the metrically homogeneous world points of its space-time manifold {section 1(a)}, and (2) the compatibility of the theory with the Riemannian metrical philosophy apparently espoused by its proponents {section 2(c)(i)}. (shrink)

Thomas Kuhn has argued that scientists never reject a paradigm without simultaneously accepting a new paradigm. Coupled with Kuhn's claim that it is paradigms as a whole, and not individual theories, that are accepted or rejected, this thesis is seen as one of Kuhn's main challenges to the rationality of science. I argue that Kuhn is mistaken in this claim; at least in some instances, science rejects a paradigm despite the absence of a successor. In particular, such a description best (...) fits Kuhn's most discussed example, the Copernican Revolution. By differentiating scientific discoveries into three types, spontaneous, implicit, and directed, we see that Kuhn's thesis holds for spontaneous and implicit discoveries, but not directed discoveries. Directed discoveries must be understood by an alternative account of falsifiability, based on argument by reductio ad absurdum rather than argument by modus tollens as traditional accounts of falsifiability would have it. (shrink)

ENGLISH ABSTRACT: Basic statements play a central role in Popper's "The Logic of Scientific Discovery", since they permit a distinction between empirical and non-empirical theories. A theory is empirical iff it consists of falsifiable statements, and statements (of any kind) are falsifiable iff they are inconsistent with at least one basic statement. Popper obviously presupposes that basic statements are themselves empirical and hence falsifiable; at any rate, he claims several times that they are falsifiable. In this paper we prove that (...) no basic statement is falsifiable, if the term 'basic statement' is to be understood according to Popper's definitions of that term. More precisely, we prove not only that no Popperian basic statement in the narrow sense of the word is falsifiable, but also that no Popperian basic statement in the broader sense, and even in the broadest possible sense, is falsifiable. This leads to the paradoxical result that, according to Popper's definitions of 'basic statement', the basis of the empirical sciences is not itself empirical. Furthermore, we point out a similar paradox as regards Popper's falsifiability scheme for theories. We close with a look at possibilities for overcoming these paradoxes. DEUTSCHE ZUSAMMENFASSUNG: Basissätze spielen eine zentrale Rolle in Poppers Logik der Forschung, denn sie erlauben die Unterscheidung zwischen empirischen und nichtempirischen Theorien: Eine Theorie ist empirisch genau dann, wenn sie aus falsifizierbaren Aussagesätzen besteht, und Aussagesätze (beliebiger Art) sind falsifizierbar genau dann, wenn sie mindestens einem Basissatz widersprechen. Popper setzt offensichtlich voraus, dassŸ die Basissätze selbst empirisch und somit falsifizierbar sind. Jedenfalls behauptet er mehrmals ihre Falsifizierbarkeit. Wir beweisen in unserem Aufsatz, dassŸ die Basissätze nicht falsifizierbar sind, und wir beweisen dies nicht nur für Poppersche Basissätze im engeren Sinn, sondern auch für Poppersche Basissätze im weiteren Sinn und schlieߟlich für Poppersche Basissätze im weitesten, mit den Vorstellungen Poppers gerade noch verträglichen Sinn. Dies führt zu dem paradoxen Ergebnis, dass nach Poppers eigenen methodologischen Postulaten die Basis der empirischen Wissenschaften nicht selbst empirisch ist. Darüber hinaus entwickeln wir ein ähnliches Paradoxon bezüglich Poppers Falsifizierbarkeitsschema für Theorien. Zum AbschlussŸ unseres Aufsatzes betrachten wir einige Möglichkeiten, die von uns entdeckten Paradoxa zu überwinden. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumFalsifiability, Causality, and the Importance of AdvocacyArjun Byju, MD (bio) and Phoebe Friesen, PhD (bio)We want to begin by thanking both Kathryn Petrozzo and Paul B. Lieberman for taking the time to read and respond to our article, “Making Up Monsters, Redirecting Blame: An Examination of Excited Delirium,” so thoughtfully. They each offered us an opportunity to consider dimensions of excited delirium that we had not encountered as (...) of yet and encouraged us to think more carefully about them. In our response, we consider each of their commentaries in turn, given that, as a philosopher and a psychiatrist, they each speak to different aspects of our argument.First, we turn to Kathryn Petrozzo’s commentary “Excited Delirium: The Self-Fulfilling Prophecy of Police Brutality.” We are grateful for her generous comments and careful engagement with our arguments. While much of the commentary is supportive of our piece, Petrozzo makes three critical and insightful points that we hope to respond to here.The first point Petrozzo makes is that our assertion that excited delirium is non-falsifiable is not supported. She suggests that those “seeking to exonerate the police/first responders responsible for these deaths, are not accepting this evidence leading them to reject the excited delirium diagnosis, but rather, are crafting an incorrect causal narrative. This is deeply problematic, but it does not necessarily render excited delirium as nonfalsifiable.”Although we are intrigued by this challenge, we would like to hear more about what it would look like to falsify the phenomenon of excited delirium. The way that the causal theories related to it are structured are such that if one causal factor is not present (e.g., drug use), then another causal factor can be located (e.g., mental health), and if that is not found, another may be simply made up (e.g., genetic predisposition), making excited delirium multiply realizable in a seemingly endless fashion. This is precisely what took place in the case of Anthany Dawson, who was initially said to have been experiencing a mental health crisis, but was later said to have died from excited delirium related to a genetic condition never identified before (Hon, 2004; Razack, 2015). [End Page 361]In practice, confirmations of excited delirium are found on the basis of various unrelated factors, such that after a death involving police force, there is almost always the option to reach for excited delirium as an explanation/exoneration. According to proponents, there is no factor that could be present that could rule out the diagnosis of excited delirium as it is currently constructed. Indeed, even in the presence of video evidence showing police officers choking an individual until they stop breathing, these deaths are still attributed to excited delirium. This seems like a clear instance of non-falsifiability.Although Petrozzo might maintain that this is simply “an incorrect causal narrative,” it is a causal narrative that aligns with the current theoretical scaffolding surrounding excited delirium.The second point Petrozzo makes is regarding widespread criticisms of Popper’s demarcation criterion of falsifiability. Indeed, this criterion has been called too inclusive, in that any empirical claim can be called falsifiable in principle—even if it refers to a future apocalypse or a UFO landing. It has also been criticized for being too exclusive, in that it ignores the “remarkable tenacity of scientific theories,” as Lakatos puts it (2009, p. 516). In practice, scientists do not merely abandon a theory if it is not supported by facts; they tend to find other explanations (e.g., the measurement was faulty) rather than accept an instance of falsification.Despite this, we believe it is still worth discussing falsifiability in the context of excited delirium for two reasons. First, while falsifiability may not be successful as a criterion that draws a line between science and pseudoscience, in this case, we argue, it still works well as a signifier of pseudoscience. Recently, many interested in the demarcation question have turned towards pluralism as a way to identify pseudoscientific practices (Pigliucci & Boudry, 2013). And excited delirium offers an excellent example of a phenomenon that bumps up against many of the features that might indicate a pseudoscientific practice... (shrink)