Thomas Mormann

We examine some of Connes’ criticisms of Robinson’s infinitesimals starting in 1995. Connes sought to exploit the Solovay model S as ammunition against non-standard analysis, but the model tends to boomerang, undercutting Connes’ own earlier work in functional analysis. Connes described the hyperreals as both a “virtual theory” and a “chimera”, yet acknowledged that his argument relies on the transfer principle. We analyze Connes’ “dart-throwing” thought experiment, but reach an opposite conclusion. In S , all definable sets of reals are Lebesgue measurable, suggesting that Connes views a theory as being “virtual” if it is not definable in a suitable model of ZFC. If so, Connes’ claim that a theory of the hyperreals is “virtual” is refuted by the existence of a definable model of the hyperreal field due to Kanovei and Shelah. Free ultrafilters aren’t definable, yet Connes exploited such ultrafilters both in his own earlier work on the classification of factors in the 1970s and 80s, and in Noncommutative Geometry, raising the question whether the latter may not be vulnerable to Connes’ criticism of virtuality. We analyze the philosophical underpinnings of Connes’ argument based on Gödel’s incompleteness theorem, and detect an apparent circularity in Connes’ logic. We document the reliance on non-constructive foundational material, and specifically on the Dixmier trace −∫ (featured on the front cover of Connes’ magnum opus) and the Hahn–Banach theorem, in Connes’ own framework. We also note an inaccuracy in Machover’s critique of infinitesimal-based pedagogy.

A possible world is a junky world if and only if each thing in it is a proper part. The possibility of junky worlds contradicts the principle of general fusion. Bohn (2009) argues for the possibility of junky worlds, Watson (2010) suggests that Bohn‘s arguments are flawed. This paper shows that the arguments of both authors leave much to be desired. First, relying on the classical results of Cantor, Zermelo, Fraenkel, and von Neumann, this paper proves the possibility of junky worlds for certain weak set theories. Second, the paradox of Burali-Forti shows that according to the Zermelo-Fraenkel set theory ZF, junky worlds are possible. Finally, it is shown that set theories are not the only sources for designing plausible models of junky worlds: Topology (and possibly other "algebraic" mathematical theories) may be used to construct models of junky worlds. In sum, junkyness is a relatively widespread feature among possible worlds.

These days, a number of philosophers of science indulge in lamenting about a crisis of their discipline. They complain about its loss of relevance, and bemoan the mar gi na lization of their dis cipline in the philosophical community and in the wider academia , Hardcastle and Richardson ). The Munich take on the philosophy of science does not succumb to this temptation. According to it, philosophy of science is well and alive. In Carlos Ulises Moulines’s Die Entwicklung der modernen Wissen schaftstheorie Eine historische Einführung the word “crisis” is used only in reference to the 1940s when clas sical logical positivism encountered some dif fi culties in dealing with problems concerning veri fi cation, the ana ly tic/synthetic distinction, and similar conundrums. For Moulines, “crisis” is not a word that applies to contemporary philosophy of science

In the philosophy of the analytical tradition, set theory and formal logic are familiar formal tools. I think there is no deep reason why the philosopher’s tool kit should be restricted to just these theories. It might well be the case—to generalize a dictum of Suppes concerning philosophy of science—that the appropriate formal device for doing philosophy is mathematics in general; it may be set theory, algebra, topology, or any other realm of mathematics. In this paper I want to employ elementary topological considerations to shed new light on the intricate problem of the relation of qualities and similarity. Thereby I want to make plausible the general thesis that topology might be a useful device for matters epistemological.

En la estructura de una teoría se han distinguido tradicionalmente dos niveles conceptual y metodológicamente distintos: el nivel empirico y el teórico. Sostenemos que este enfoque de! doble nivel es incompleto y que conduce además a distorsiones, tanto en la comprensión filosofíca de las teorías como en la de su uso en la praxis científica. En este artículo se diseña un nuevo enfoque, segun el cual las teorías se conciben como estructuras representacionales tripartitas, que comprenden tres niveles conceptual y metodológicamente distintos: el nivel de los datos, el de los fenómenos y el de los constructos teóricos. Se exploran las relaciones estructurales básicas entre los tres niveles y se muestran algunas aplicaciones relativas a los problemas de la idealización.Traditionally two different conceptual and methodological levels are distinguished within a theory: the empirical and the theoretical level. We argue that this two-level account is incomplete, leading to distortions of the philosophical understanding of theories and their usage in scientific praxis. We sketch a new account according to which theories are conceptualizad as three-tiered representational structures comprising three conceptually and methodologically different levels, to wit, the levels of data, phenomena and the level of theoretical constructs. Basic structural relations between these differentlevels are studied, some applications concerning problems of idealization are given

Abstract: One of the institutional highlights of the encounter between Austrian “wissen¬schaftliche Philosophie” and French “philosophie scientifique” in the first half of the 20th century was the “First International Congress for Unity of Science” that took place 1935 in Paris. In my contribution I deal with an episode of the philosophical mega-event whose protagonist was the American philosopher and semiotician Charles William Morris. At the Paris congress he presented his programme of a comprehensive, practice-oriented scientific philosophy and, in a more elaborated version he published it two years later in Logical Positivism, Pragmatism and Scientific Empiricism (Morris 1937). Morris aimed at a synthesis of formalism, pragmatism, and traditional empiricism that combined the virtues of these accounts while avoided their shortocmings. The core of approach was a comprehensive theory of the concept of meaning. Through an analysis of the concept of meaning he sought to sort out the existing differences and the options for a possible future rapprochment between logical empiricism and pragmatism. Against the overly narrow logical empiricist understanding of philosophy as the syntax of the language of science Morris argued for a “scientific pragmatism” that comprised four levels: (1) Philosophy as Logic of Science, (2) Philosophy as Clarification of Meaning (Peirce), (3) Philosophy as Empirical Axiology (Dewey), and (4) Philosophy as Empirical Cosmology (Whitehead).

The aim of this paper is make a contribution to the ongoing search for an adequate concept of the a priori element in scientific knowledge. The point of departure is C.I. Lewis’s account of a pragmatic a priori put forward in his "Mind and the World Order" (1929). Recently, Hasok Chang in "Contingent Transcendental Arguments for Metaphysical Principles" (2008) reconsidered Lewis’s pragmatic a priori and proposed to conceive it as the basic ingredient of the dynamics of an embodied scientific reason. The present paper intends to further elaborate Chang’s account by relating it with some conceptual tools from cognitive semantics and certain ideas that first emerged in the context of the category-theoretical foundations of mathematics.

A basic thesis of Neokantian epistemology and philosophy of science contends that the knowing subject and the object to be known are only abstractions. What really exists, is the relation between both. For the elucidation of this “knowledge relation ("Erkenntnisrelation") the Neokantians of the Marburg school used a variety of mathematical metaphors. In this con-tribution I reconsider some of these metaphors proposed by Paul Natorp, who was one of the leading members of the Marburg school. It is shown that Natorp's metaphors are not unrelated to those used in some currents of contemporary epistemology and philosophy of science.

In this paper we discuss three examples of the appropriation of Kuhn’s ideas in philosophy of science. First we deal with classical logical empiricism. Perhaps somewhat surprisingly, the arch-logical empiricist Carnap considered Kuhn’s socio-historical account as a useful complementation, and not as a threat of the philosophy of science of logical empiricism. As a second example we consider the attempt of the so-called struc- turalist philosophy of science to provide a “rational reconstruction” of Kuhn’s approach. Finally, we will deal with Friedman’s proposal to apply Kuhn’s ideas to the formulation of a modernized, historically enlightened Kantian approach that is based on the concept of a non-apodictic constitutive and historically moving a priori.

In this paper we argue for the thesis that theories are to be considered as representations. The term "representation" is used in a sense inspired by its mathematical meaning. Our main thesis asserts that theories of empirical theories can be conceived as geometrical representations. This idea may be traced back to Galileo. The geometric format of empirical theories should not be simply considered as a clever device for displaying a theory. Rather, the geometrical character deeply influences the theory s ontology. We argue that it would be desastrous for philosophy if it followed Rorty s "neo-pragmatic" proposal to discard the concept of representation from philosophical discourse.

The aim of this paper is to show that topology has a bearing on<br><br>combinatorial theories of possibility. The approach developed in this article is “mapping account” considering combinatorial worlds as mappings from individuals to properties. Topological structures are used to define constraints on the mappings thereby characterizing the “really possible” combinations. The mapping approach avoids the well-known incompatibility problems. Moreover, it is compatible with atomistic as well as with non-atomistic ontologies.It helps to elucidate the positions of logical atomism and monism with theaid of topological separation axioms.

The general aim of this paper is to introduce some ideas of the theory of infinite topological games into the philosophical debate on supertasks. First, we discuss the elementary aspects of some infinite topological games, among them the Banach-Mazur game.Then it is shown that the Banach-Mazur game may be conceived as a Newtonian supertask.In section 4 we propose to conceive physical experiments as infinite games. This leads to the distinction between determined and undetermined experiments and the problem of how it is related to that between determinism and indeter-minism. Finally the role of the Axiom of Choice as a source of indetermi-nacy of supertasks is discussed.

Der Antirepräsentationalismus behauptet, es sei an der Zeit, das auf dem Begriff der Repräsentation basierende Paradigma der Philosophie zu verabschieden. Die von Rorty und anderen propagierte Unterscheidung von Repräsentationalismus und Antirepräsentationalismus beruht jedoch auf einem verkürzten Repräsentationsbegriff als Spiegelung. Der Begriff der Repräsentation, so wie er in der Philosophie und Wissenschaft gebraucht wird, hat nur wenig mit Spiegelung zu tun. Statt den Begriff der Repräsentation mit Hilfe der Spiegelungsmetapher zu explizieren, sollte man Repräsentation als strukturerhaltende Abbildung konzipieren. Dadurch lassen sich die für den Repräsentationsbegriff wesentlichen pragmatischen Aspekte der Reduktion und Induktion von Komplexität explizieren. Der Zusammenhang der gegenläufigen Aspekte Reduktion und Induktion wird an Beispielen aus der Konstitution extensiver Größen sowie an Cassirers Theorie der Konstitution von Erkenntnis und Wirklichkeit erörtert. Man sollte daher den Begriff der Repräsentation nicht aus dem philosophischen Diskurs eliminieren, sondern versuchen, die Ansätze einer allgemeinen pragmatischen Repräsentationstheorie auszubauen

David Lewis famously argued against structural universals since they allegedly required what he called a composition “sui generis” that differed from standard mereological com¬position. In this paper it is shown that, although traditional Boolean mereology does not describe parthood and composition in its full generality, a better and more comprehensive theory is provided by the foundational theory of categories. In this category-theoretical framework a theory of structural universals can be formulated that overcomes the conceptual difficulties that Lewis and his followers regarded as unsurmountable. As a concrete example of structural universals groups are considered in some detail.