Scientific Change

Philosophers and scientists are social epistemic agents. As such, they ought to behave in accordance with epistemic norms governing the behavior of social epistemic agents.

Until the middle of the present century it was a commonly accepted opinion that theory change in science was the expression of cumulative progress consisting in the acquisition of new truths and the elimination of old errors. Logical empiricists developed this idea through a deductive model, saying that a theory T superseding a theory T must be able logically to explain whatever T explained and something more as well. Popper too shared this model, but stressed that T explains the old (...) known facts in its own new way. The further pursual of this line quickly led to the thesis of the non-comparability or incommensurability of theories: if T and T are different, then the very concepts which have the same denomination in both actually have different meanings; in such a way any sentence whatever has different meanings in T and in T and cannot serve to compare them. owing to this, the deductive model was abandoned as a tool for understanding theory change and scientific progress, and other models were proposed by people such as Lakatos, Kuhn, Feyerabend, Sneed and Stegmüller. The common feature of all these new positions may be seen in the claim that no possibility exists of interpreting theory change in terms of the cumulative acquisition of truth. It seems to us that the older and the newer positions are one-sided, and, in order to eliminate their respective shortcomings, we propose to interpret theory change in a new way.The starting point consists in recognizing that every scientific discipline singles out its specific domain of objects by selecting a few specific predicates for its discourse. Some of these predicates must be operational and they determine the objects of the theory concerned. In the case of a transition from T to T, we must consider whether or not the operational predicates remain unchanged, in the sense of being still related to the same operations. If they do not change in their relation to operations, then T and T are comparable. If the operational predicates are not all identical in T and T, the two theories show a rather high degree of incommensurability, and this happens because they do not refer to the same objects. Theory change means in this case change of objects. But now we can see that even incommensurability is compatible with progress conceived as the accumulation of truth. Indeed, T and T remain true about their respective objects, and the global amount of truth acquired is increased. (shrink)

In this article, I discuss Gadamer's hermeneutic account of understanding as an alternative to Kuhn's incommensurability thesis. After a brief account of Kuhn's aesthetic account and arguments against it, I argue that the linguistic account faces a paradox that results from Kuhn's objectivist account of understanding, and his lack of historical reflexivity. The statement 'Languages are incommensurable' is not a unique view of language, and is thus subject to contest by incommensurable readings. Resolving the paradox requires an account of incommensurability (...) that is self-referentially consistent, open-ended, and historically reflexive whereby we recognize that our very interest in incommensurability is historically conditioned. By meeting these conditions, Gadamer's account of historical understanding offers a middle ground between two extremes: on the one side is the claim that understanding involves becoming a native of an incommensurable language, and on the other side is the rejection of the prospect of understanding a contextually removed language altogether. Gadamer is discussed as a mediator between Kuhn's epistemic and historical projects, and thus paves the way for a new hermeneutics of science. The notions of traditional horizon, historically effected consciousness, the universality of interpretation, alienation, dialogical openness, and the fusion of horizons are also discussed. (shrink)

The aim of this paper is to analyse the differences between the notions of incommensurability and inconsistency. The concept of incommensurability taken into account is restricted to the one of non-trivial incommensurability, which, in turn, will be associated with local untranslatability. Logical, ontological, and epistemological differences between the two former notions will be depicted. It will be shown that incommensurability consists of a sort of non-contradictory opposition relation.

Several diagrams and tables from review articles during the Ox-Phos Controversy serve as an occasion to assess the nature of competition in models of theory choice in science. Many models follow "Super-Bowl" principles of polar, either-or, winner-take-all competition. A significant alternative highlighted by this episode, however, is the differentiation of domains. Incommensurability and the partial divergence of overlapping domains serve both as signals and context for shifting frameworks of competition. Appropriate strategies may thus help researchers diagnose the status of competition (...) and shape their research accordingly. (shrink)

Putnam originally developed his causal theory of meaning in order to support scientific realism and reject the notion of incommensurability. Later he gave up this position and adopted instead what he called ‘internal realism’, but apparently without changing his mind on topics related to his former philosophy of language. The question must arise whether internal realism, which actually is a species of antirealism, is compatible with the causal theory of meaning. In giving an answer I begin with an analysis of (...) the content and metaphysical background of scientific realism. I show that it presupposes metaphysical realism and that Putnam's philosophical conversion is due to his becoming aware of the latter's incoherence. After giving a brief sketch of internal realism I conclude by arguing that within this new theoretical framework the causal theory of meaning loses its force as a weapon against incommensurability. (shrink)

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One important problem concerning incommensurability is to explain how theories that are incommensurable can nevertheless compete. In this paper I shall briefly review Kuhn’s account of the difference between revolutionary and non-revolutionary conceptual developments. I shall argue that his taxonomic approach and the no-overlap principle it entails does not suffice to distinguish between revolutionary and non-revolutionary developments. I shall show that his approach builds mainly on analyses of feature correlations, and that it is necessary to include explanations of these feature (...) correlations as well. This puts emphasis on theories; an element which has played only a humble role in Kuhn’s work on scientific lexicons from the 1980s and early 1990s. I shall argue that on the basis of this extended account of conceptual structures, incommensurability can be understood as overlapping feature correlations that are covered by different explanations.RésuméUn problème important à propos de l’incommensurabilité est d’expliquer comment des théories qui sont incommensurables peuvent néanmoins entrer en compétition. Dans cet article, on examine brièvement le compte rendu kuhnien de la différence entre transitions conceptuelles révolutionnaires et non révolutionnaires. On argue que l’approche taxonomique kuhnienne et le principe de non-recouvrement qui le sous-tend ne suffisent pas à distinguer entre ces deux types de transition. On montre que cette approche s’appuie principalement sur des analyses de corrélations entre traits, alors qu’il est nécessaire de prendre de plus en considération les explications en vigueur de ces corrélations entre traits. Ceci met l’accent sur les théories, un élément qui n’a joué qu’un rôle modeste dans le travail que Kuhn a consacré aux lexiques scientifiques des années 1980 au début des années 1990. On argue que sur la base de ce compte rendu élargi des structures conceptuelles, l’incommensurabilité correspond à des corrélations qui d’un côté portent sur des traits présentant des recouvrements et de l’autre sont subsumées sous des explications différentes. (shrink)

Significant claims about science education form an integral part of Thomas Kuhn's philosophy. Since the late 1950s, when Kuhn started wrestling with the ideas of ‘normal research’ and ‘convergent thought’, the nature of science education has played an important role in his argument. Hence, the nature of science education is an essential aspect of the phase-model of scientific development developed in his famous The Structure of Scientific Revolutions, just as his later work on categories and conceptual structures takes its starting (...) point in the transmission rather than the creation of concepts and categories. (shrink)

Thomas Kuhn's Structure of Scientific Revolutions became the most widely read book about science in the twentieth century. His terms 'paradigm' and 'scientific revolution' entered everyday speech, but they remain controversial. In the second half of the twentieth century, the new field of cognitive science combined empirical psychology, computer science, and neuroscience. In this book, the theories of concepts developed by cognitive scientists are used to evaluate and extend Kuhn's most influential ideas. Based on case studies of the Copernican revolution, (...) the discovery of nuclear fission, and an elaboration of Kuhn's famous 'ducks and geese' example of concept learning, this volume, first published in 2006, offers accounts of the nature of normal and revolutionary science, the function of anomalies, and the nature of incommensurability. (shrink)

Drawing on the results of modem psychology and cognitive science we suggest that the traditional theory of concepts is no longer tenable, and that the alternative account proposed by Kuhn may now be seen to have independent empirical support quite apart from its success as part of an account of scientific change. We suggest that these mechanisms can also be understood as special cases of general cognitive structures revealed by cognitive science. Against this background, incommensurability is not an insurmountable obstacle (...) to accepting Kuhn's position, as many philosophers of science still believe. Rather it becomes a natural consequence of cognitive structures that appear in all human beings. (shrink)

Sarah Waller proposes that cognitive therapists and philosophical counselors ought to consider the feelings of the client of paramount importance in belief system change rather than the rationality of the belief system. I offer an alternative strategy of counseling that reinstates the place of rational belief revision while still respecting the importance of emotions. Waller claims that, because of the problem of under-determination, the counseling goal of rational belief revision can be trumped by the goal of improved client affect. I (...) suggest that, if we consider a different ontology for the domain of counseling - one whose objects are dialogues (the goal of counseling becomes greater information of dialogues), we can accommodate a place for emotions in rational belief revision. I then note some limitations of the new proposal and the possibility of incommensurability in the comparison of our different views. (shrink)

In this paper I address some of the problems that the historical development of science poses for a realist and discuss whether a realist construal of scientific activity is conducive to historiographical practice. First, I discuss, by means of historical examples, Ian Hacking's defense of entity realism. Second, I try to show, drawing on Kuhn's recent work on incommensurability, that the realism problem is relevant to historiography and that a realist position entails a particular historiographical strategy, which faces problems. Finally, (...) I suggest that for historiographical purposes an agnostic attitude with respect to scientific theories and unobservable entities is the most appropriate. (shrink)

Thirty years after its publication, Thomas Kuhn's The Structure of Scientific Revolutions is still the source of much discussion in economics. Its rel-ativistic tone has often been used to fuel the claims of dissident traditions against the prevailing orthodoxy, or at least to plead the case for intellectual pluralism. Through his arguments regarding the incommensurability of different theoretical approaches to a particular subject, Kuhn's work has allowed many to argue that dissident traditions are just as legitimate as orthodoxy for analyzing (...) a subject, since there is no objective or independent means of arbitrating between them. This has caused an opposing response by those more supportive of the prevailing theoretical approach to economics. The latter have tried to find a defense to relativist challenges in more “rational” philosophies of science, such as that of Lakatos. (shrink)

Central to Kuhn's notion of incommensurability are the ideas of meaning variance and lexicon, and the impossibility of translation of terms across different theories. Such a notion of incommensurability is based on a particular understanding of what a scientific language is. In this paper we first attempt to understand this notion of scientific language in the context of incommensurability. We consider the consequences of the essential multisemiotic character of scientific theories and show how this leads to even a single theory (...) being potentially 'internally incommensurable'. We then discuss Kuhn's lexicon-based approach to incommensurability and the problems associated with it. Finally we argue that this approach by Kuhn has interesting overlaps with the problem of meaning associated with multisemiosis, particularly the challenge of understanding the process of symbolization in scientific theories. (shrink)

The thesis concerns the claim that competing scientific theories are, in important cases, "incommensurable". It has been argued that since theoretical terms derive their meaning from the theory in which they occur, the transition from one theory to another involves significant changes in the meanings of terms. The absence of common meanings has been taken to preclude the possibility of logical and evidential comparisons between competing theories. Furthermore, since such theories are not then alternative accounts of the same domain, standard (...) treatments of intertheoretical debates are seen as hopelessly misguided. The thesis examines these claims in particular and the impact of the theory of reference on the incommensurability argument generally. ;In Chapter I the incommensurabilist argument is considered in detail along with recent criticisms that it involves a confusion of meaning and reference and that its conclusions can be avoided by admitting meaning-variance and relying on referential stability. These responses are found to be inadequate and the argument is shown to be supported by traditional description theory. ;Putnam and others have claimed that the incommensurabilist argument can be blocked by discrediting the theory of meaning on which it is based. Arguments against the description theory are reviewed in the second chapter, and these polemics are shown to be not as effective as thought. ;Chapter III is an examination of the theory of direct reference, which is found to fail to provide a workable treatment of theoretical terms. Furthermore, Putnam's "Twin-Earth" example is shown to beg important questions with respect to the incommensurabilist argument. ;In the fourth chapter it is argued that prospects for logical comparison are not lost when existential commitments change. A preliminary proposal is made which recognizes the "theory-ladenness" of scientific terms, yet permits logical assessment of theory change as well as the preservation of ontological commitments. The model proposed allows that certain key terms in actually competing alternative theories are "co-referential". ;Having recognized that neither theory comparison nor the preservation of existential commitments are precluded by semantic considerations, the incommensurabilist position is seen to present an unfounded and distorted view of theory change. (shrink)

This article argues that the limited influence of Ludwik Fleck's ideas on philosophy of science is due not only to their indirect dissemination by way of Thomas Kuhn, but also to an incommensurability between the standard conceptual framework of history and philosophy of science and Fleck's own more integratedly historico-social and praxis-oriented approach to understanding the evolution of scientific discovery. What Kuhn named "paradigm" offers a periphrastic rendering or oblique translation of Fleck's Denkstil/Denkkollektiv , a derivation that may also account (...) for the lability of the term "paradigm". This was due not to Kuhn's unwillingness to credit Fleck but rather to the cold war political circumstances surrounding the writing of The Structure of Scientific Revolutions . Following a discussion of Fleck's anatomical allusions, I include a brief discussion of Aristotle (on menstruation and darkened mirrors) and conclude with a reference to the productivity of error in Mach and Nietzsche. (shrink)

The thesis of the incommensurability of competing scientific theories, as it has been formulated and defended by Thomas Kuhn and Paul Feyerabend, implies the following: there will be competing scientific theories between which there will exist no neutral perspective from which to evaluate the merits of those theories with regards to truth. If this thesis were true, it would threaten what I take to be basic epistemic values, the values of seeking truth and avoiding error. To pass from one theory (...) to another incommensurable with it, one must pass to a theory which, from one's original perspective, appears absurd, trivially false, or even meaningless. Doing so obviously flouts error avoidance. ;Unlike many who have opposed incommensurability, I argue that the incommensurabilist's semantic vision of alternative and widely divergent conceptual schemes is a coherent and plausible one, but I also contend that such a vision cannot possibly characterize rival scientific theories. This last fact removes the threat to epistemology since semantic incommensurability will only arise in situations in which comparison between theories with respect to truth is not at issue. My arguments for these claims are based on a positive account of scientific theories and their interpretation which makes clear how we can discover conceptual overlaps and ultimately find a neutral point of view from which non-question-begging adjudication between rival theories can take place. ;Turning from the general, philosophical arguments which I present in support of my thesis, I examine particular epsiodes from the history of science to illustrate how the view I defend captures the actual evolution of scientific theories. Drawing upon disputes which were central to the Copernican Revolution as well as a more contemporary debate between particular interpretations of Quantum Mechanics, I demonstrate that, although these cases may have required scientists to specify types of disagreements that they were not accustomed to specifying, the rival theories in these instances are nonetheless not incommensurable in the epistemologically threatening way described above. (shrink)

In its first part, this paper shows why a recently made attempt to reduce the special theory of relativity to Newtonian kinematics is bound to fail. In the second part, we propose a differentiated notion of incommensurability which enables us to amend the contention that the special theory of relatively and Newtonian kinematics are “incommensurable”.

Radical scientific discovery and the associated radical “paradigm change” are treated here as following from the disclosure of what I call background ‘assumptions’. These are taken as more or less equivalent to the “hinge propositions” that Wittgenstein discusses in his On Certainty. On this basis, various issues connected to meaning variance, theory change, incommensurability and so forth, are discussed. It is shown that Kuhn’s overall account need not, with qualifications, imply either idealism or relativism while rationality and scientific progress can (...) be saved in a way that may be acceptable by practising scientists.RésuméLa découverte scientifique radicale, et le changement radical de paradigme associé, sont traités ici comme découlant de la mise à jour de ce qu’on appelle des ‘assomptions’ d’arrière-plan. Celles-ci sont considérées comme plus ou moins équivalentes aux ‘propositions charnières’ discutées par Wittgenstein dans De la certitude. Sur cette base, diverses questions liées aux changements de signification, au changement théorique, à l’incommensurabilité, etc., sont discutées. On montre que la conception d’ensemble de Kuhn, une fois précisée, n’implique ni l’idéalisme ni le relativisme, et que la rationalité et le progrès scientifique peuvent être sauvés d’une manière acceptable par les scientifiques praticiens. (shrink)

: This paper continues my application of theories of concepts developed in cognitive psychology to clarify issues in Kuhn's mature account of scientific change. I argue that incommensurability is typically neither global nor total, and that the corresponding form of scientific change occurs incrementally. Incommensurability can now be seen as a local phenomenon restricted to particular points in a conceptual framework represented by a set of nodes. The unaffected parts in the framework constitute the basis for continued communication between the (...) communities supporting alternative structures. The importance of a node is a measure of the severity of incommensurability introduced by replacing it. Such replacements occur incrementally so that changes like that from the conceptual structure of Aristotelian celestial physics to the conceptual structure of Newtonian celestial physics occur in small stages over time, and for each change it is in principle possible to identify the arguments and evidence that led historical actors to make the revisions. Thus the process of scientific change is a rational one, even when its beginning and end points are incommensurable conceptual structures. It is also apparent, from a detailed examination of the conceptual structure of astronomy at the time of Copernicus, thatthe kind of conceptual difficulty identified as incommensurability may occur within a single scientific tradition as well as between two rival traditions. (shrink)

The paper analyses the development of some themes in the contemporary philosophy of science in Italy. Section 1 reviews the dabate on the legacy of neopositivism. The spread of the philosophy of Popper is outlined in Section 2, with particular regard to the problem of the vindication of induction. Section 3 deals with the debate on the incommensurability thesis, while Section 4 examines its consequences on the possible relationships between historical and epistemological studies of science. The last section is devoted (...) to one of the most recent trends in the Italian philosophy of science: the resumption of Aristotelian dialectics. (shrink)

The rationality of scientific concept formation in theory transitions, challenged by the thesis of semantic incommensurability, can be restored by theChains of Meaning approach to concept formation. According to this approach, concepts of different, succeeding theories may be identified with respect to referential meaning, in spite of grave diversity of the mathematical structures characterizing them in their respective theories. The criterion of referential identity for concepts is that they meet a relation ofsemantic embedding, i.e. that the embedding concept can be (...) substituted by the embedded one in classical limit situations. Three case studies from contemporary physics theories will be used to show that the Chains of Meaning approach not only yields meaning comparisons for already established concepts (as for Newtonian and Schwarzschild mass) but is also well suited to characterize actual scientific strategies of concept formation in yet open cases such as black hole entropy or relativistic thermodynamics. (shrink)

In focusing their view on Kuhn, Robert Veatch and William Stempsey ignore alternative sources of insight from other voices that could help move us beyond incommensurability. Richard Rorty and Helen Longino, for example, offer another view of science and objectivity with constructive insight for the practice of science and medicine. Keywords: positivism, relativism, scientific knowledge, incommensurability, Kuhn, Rorty, Longino CiteULike Connotea Del.icio.us What's this?

Attempting to compare scientific theories requires a philosophical model of meaning. Yet different scientific theories have at times—particularly in early chemistry—pre-supposed disparate theories of meaning. When two theories of meaning are incommensurable, we must say that the scientific theories that rely upon them are meta-incommensurable. Meta- incommensurability is a more profound sceptical threat to science since, unlike first-order incommensurability, it implies complete incomparability.

Carrier’s paper is mainly a defence of incommensurability as “a sensible notion”, on the basis of the context theory of meaning. I shall here discuss his semantic reconstruction of the notion. His argument consists in exhibiting cases where incommensurability is instantiated thanks to a symmetrical proof of untranslatability, based on a distinction between two determinants of the meaning of a concept. I shall mainly show that a logical asymmetry in the distinction hinders the argument from achieving its goal. I shall (...) then defend that a notion that plays a secondary role in Carrier’s argument, i.e. “the set of situation to which a concept is properly applied”, should be placed at centre stage for the determination of the meaning of a concept and thence for the appraisal of the notion of incommensurability. I shall finally sketch an alternative reconstruction of the notion of incommensurability, based on the semantic view of science instead of the semantic theory of meaning.RésuméL’article de Carrier a pour but principal de reconstruire la notion d’incommensurabilité sur la base de la théorie contextuelle de la signification. C’est cette reconstruction dite sémantique que je discuterai ici. La stratégie de Carrier consiste à exhiber deux cas d’incommensurabilité sur la base d’une preuve symétrique d’intraductibilité, elle-même fondée sur la distinction entre deux éléments déterminant la signification d’un concept. Je montrerai principalement que la symétrie de l’argument est fautive et que la distinction sur laquelle il est fondée ne tient pas. J’argumenterai ensuite en faveur de la revalorisation d’une notion qui joue un rôle secondaire dans l’argument de Carrier, savoir « l’ensemble des situations dans lesquelles le concept est correctement appliqué », tant pour la détermination de la signification d’un concept que pour l’évaluation de la notion d’incommensurabilité. Je tenterai d’ouvrir enfin une autre voie pour la reconstruction de l’incommensurabilité, fondée, non pas sur la théorie sémantique de la signification, mais sur la théorie sémantique des sciences. (shrink)

Kuhn’s Structure of Scientific Revolutions is one of the most cited books of the twentieth century. Its iconic and controversial nature has obscured its message. What did Kuhn really intend with Structure and what is its real significance? -/- 1 Introduction -/- 2 The Central Ideas of Structure -/- 3 The Philosophical Targets of Structure -/- 4 Interpreting and Misinterpreting Structure -/- 4.1 Naturalism -/- 4.2 World-change -/- 4.3 Incommensurability -/- 4.4 Progress and the nature of revolutionary change -/- 4.5 (...) Relativism, rationality, and realism -/- 4.6 History and sociology of science -/- 4.7 Wittgenstein -/- 5 After Structure. (shrink)

Thomas Kuhn was undoubtedly the strongest influence on the philosophy of science in the last third of the twentieth century. Yet today, at the beginning of the twenty-first century it is unclear what his legacy really is. In the philosophy of science there is no characteristically Kuhnian school. This could be because we are all Kuhnians now. But it might also be because Kuhn’s thought, although revolutionary in its time, has since been superseded. In a sense both may be true. (...) We are all Copernicans—yet almost everything Copernicus believed we now disbelieve. In this paper I shall examine the development of Kuhn’s thought in connection with changes in the philosophy of science during the second half of the twentieth century. Now that philosophy in general, philosophy of science in particular, is in a post-positivist era, we all share Kuhn’s rejection of positivism. But we do not, for the most part, share Kuhn’s belief in incommensurability, or his scepticism about truth and objective knowledge. Just as in Copernicus’ case, Kuhn initiated a revolution that went far beyond what he himself envisaged or even properly understood. (shrink)

Kuhn’s Structure of Scientific Revolutions is notable for the readiness with which it drew on the results of cognitive psychology. These naturalistic elements were not well received and Kuhn did not subsequently develop them in his published work. Nonetheless, in a philosophical climate more receptive to naturalism, we are able to give a more positive evaluation of Kuhn’s proposals. Recently, philosophers such as Nersessian, Nickles, Andersen, Barker, and Chen have used the results of work on case-based reasoning, analogical thinking, dynamic (...) frames, and the like to illuminate and develop various aspects of Kuhn’s thought in Structure. In particular this work aims to give depth to the Kuhnian concepts of a paradigm and incommensurability. I review this work and identify two broad strands of research. One emphasizes work on concepts; the other focusses on cognitive habits. Contrasting these, I argue that the conceptual strand fails to be a complete account of scientific revolutions. We need a broad approach that draws on a variety of resources in psychology and cognitive science.La estructura de las revoluciones científicas de Kuhn es destacable por la facilidad con que aprovecha los resultados de la psicología cognitiva. Estos elementos naturalistas no tuvieron una buena acogida y Kuhn no los desarrolló posteriormente en su trabajo publicado. No obstante, desde un ambiente filosófico más receptivo hacia el naturalismo podemos ofrecer una evaluación más positiva de las propuestas de Kuhn. Recientemente, algunos filósofos como Nersessian, Nickles, Andersen, Barker y Chen han utilizado los resultados del trabajo sobre el razonamiento basado en casos, el pensamiento analógico, los marcos dinámicos, etc., para iluminar y desarrollar varios aspectos del pensamiento de Kuhn en La estructura. En particular, este trabajo intenta dar profundidad a los conceptos kuhnianos de paradigma e inconmensurabilidad. En este artículo examino dicho trabajo e identifico dos principales corrientes de investigación. Una de ellas subraya el trabajo sobre conceptos y la otra se centra en los hábitos cognitivos. Después de contrastar ambas, sostengo que la corriente conceptual no logra ser una explicación completa de las revoluciones científicas. Necesitamos una perspectiva amplia que aproveche una variedad de recursos de la psicología y la ciencia cognitiva. (shrink)

The Structure of Scientific Revolutions is one of the most cited academic books of all time. His contribution to the philosophy science marked not only a break with several key positivist doctrines but also inaugurated a new style of philosophy of science that brought it much closer to the history of science. His account of the development of science held that science enjoys periods of stable growth punctuated by revisionary revolutions, to which he added the controversial ‘incommensurability thesis’, that theories (...) from differing periods suffer from certain deep kinds of failure of comparability. (shrink)

In this paper I argue that we can understand incommensurability in a naturalistic, psychological manner. Cognitive habits can be acquired and so differ between individuals. Drawing on psychological work concerning analogical thinking and thinking with schemata, I argue that incommensurability arises between individuals with different cognitive habits and between groups with different shared cognitive habits.

I argue that the naturalism of Thomas Kuhn's "The Structure of Scientific Revolutions," which he himself later ignored, is worthy of rehabilitation. A naturalistic conception of paradigms is ripe for development with the tools of cognitive science. As a consequence a naturalistic understanding of world-change and incommensurability is also viable.