This paper reconstructs the American reception of logical positivism in the early 1930s. I argue that Moritz Schlick (who had visiting positions at Stanford and Berkeley between 1929 and 1932) and Herbert Feigl (who visited Harvard in the 1930-31 academic year) played a crucial role in promoting the *Wissenschaftliche Weltauffassung*, years before members of the Vienna Circle, the Berlin Group, and the Lvov-Warsaw school would seek refuge in the United States. Building on archive material from the Wiener Kreis Archiv, the (...) Harvard University Archives, and the Herbert Feigl Papers, as well as a large number of publications in American philosophy journals from the early 1930s, I reconstruct the subtle transformation of the American philosophical landscape in the years immediately preceding the European exodus. I argue that (1) American philosophical discussions about meaning and significance and (2) internal dynamics in the Vienna Circle between 1929 and 1931 significantly impacted the way in which US philosophers came to perceive logical positivism. (shrink)

Discussions of the relation between pragmatism and logical empiricism tend to focus on the period when the logical empiricists found themselves in exile, mostly in the United States, and then attempt to gauge the actual extent of their convergence. My concern lies with the period before that and the question whether pragmatism had an earlier influence on the development of logical empiricism, especially on the thought of the former members of the “first” Vienna Circle. I argue for a substantially qualified (...) affirmative answer. (shrink)

Pierre Duhem's often unrecognized influence on twentieth-century philosophy of science is illustrated by an analysis of his significant if also largely unrecognized influence on Albert Einstein. Einstein's first acquaintance with Duhem's La Théorie physique, son objet et sa structure around 1909 is strongly suggested by his close personal and professional relationship with Duhem's German translator, Friedrich Adler. The central role of a Duhemian holistic, underdeterminationist variety of conventionalism in Einstein's thought is examined at length, with special emphasis on Einstein's deployment (...) of Duhemian arguments in his debates with neo-Kantian interpreters of relativity and in his critique of the empiricist doctrines of theory testing advanced by Schlick, Reichenbach, and Carnap. Most striking is Einstein's 1949 criticism of the verificationist conception of meaning from a holistic point of view, anticipating by two years the rather similar, but more famous criticism advanced independently by Quine in Two Dogmas of Empiricism. (shrink)

Discussions of the metaphysical status of spacetime assume that a spacetime theory offers a causal explanation of phenomena of relative motion, and that the fundamental philosophical question is whether the inference to that explanation is warranted. I argue that those assumptions are mistaken, because they ignore the essential character of spacetime theory as a kind of physical geometry. As such, a spacetime theory does notcausally explain phenomena of motion, but uses them to construct physicaldefinitions of basic geometrical structures by coordinating (...) them with dynamical laws. I suggest that this view of spacetime theories leads to a clearer view of the philosophical foundations of general relativity and its place in the historical evolution of spacetime theory. I also argue that this view provides a much clearer and more defensible account of what is entailed by realism concerning spacetime. (shrink)

We present a new metaphysical framework for physics that is conceptually clear, ontologically parsimonious, and empirically adequate. This framework relies on the notion of self-subsisting structure, that is, a set of fundamental physical elements whose individuation and behavior are described in purely relational terms, without any need for a background spacetime. Although the specification of the fundamental elements of the ontology depends on the particular physical domain considered---and is thus susceptible to scientific progress---, the empirically successful structural features of the (...) framework are preserved through theory change. The kinematics and dynamics of these self-subsisting structures are technically implemented using the theoretical framework of Pure Shape Dynamics, which provides a completely relational physical description of a system in terms of the intrinsic geometry of a suitably defined space called shape space. (shrink)

The `problem of time' is a cluster of interpretational and formal issues in the foundations of general relativity relating to both the representation of time in the classical canonical formalism, and to the quantization of the theory. The purpose of this short chapter is to provide an accessible introduction to the problem.

We propose a solution to the problem of time for systems with a single global Hamiltonian constraint. Our solution stems from the observation that, for these theories, conventional gauge theory methods fail to capture the full classical dynamics of the system and must therefore be deemed inappropriate. We propose a new strategy for consistently quantizing systems with a relational notion of time that does capture the full classical dynamics of the system and allows for evolution parametrized by an equitable internal (...) clock. This proposal contains the minimal temporal structure necessary to retain the ordering of events required to describe classical evolution. In the context of shape dynamics (an equivalent formulation of general relativity that is locally scale invariant and free of the local problem of time) our proposal can be shown to constitute a natural methodology for describing dynamical evolution in quantum gravity and to lead to a quantum theory analogous to the Dirac quantization of unimodular gravity. (shrink)

The theory of knowledge in early twentieth-century Anglo American philosophy was oriented toward phenomenally described cognition. There was a healthy respect for the mind-body problem, which meant that phenomena in both the mental and physical domains were taken seriously. Bertrand Russell's developing position on sense-data and momentary particulars drew upon, and ultimately became like, the neutral monism of Ernst Mach and William James. Due to a more recent behaviorist and physicalist inspired "fear of the mental", this development has been down-played (...) in historical work on early analytic philosophy. Such neglect assumes that the "linguistic turn" is a proper and permanent effect of twentieth-century philosophy, an assumption that distorts early analytic historiography, and begs a substantive philosophical question about thought and cognition. (shrink)

Symplectic reduction is a formal process through which degeneracy within the mathematical representations of physical systems displaying gauge symmetry can be controlled via the construction of a reduced phase space. Typically such reduced spaces provide us with a formalism for representing both instantaneous states and evolution uniquely and for this reason can be justifiably afforded the status of fun- damental dynamical arena - the otiose structure having been eliminated from the original phase space. Essential to the application of symplectic reduction (...) is the precept that the first class constraints are the relevant gauge generators. This prescription becomes highly problematic for reparameterization invariant theories within which the Hamiltonian itself is a constraint; not least because it would seem to render prima facie distinct stages of a history physically identical and observable functions changeless. Here we will consider this problem of time within non-relativistic me- chanical theory with a view to both more fully understanding the temporal struc- ture of these timeless theories and better appreciating the corresponding issues in relativistic mechanics. For the case of nonrelativistic reparameterization invariant theory application of symplectic reduction will be demonstrated to be both unnec- essary; since the degeneracy involved is benign; and inappropriate; since it leads to a trivial theory. With this anti-reductive position established we will then examine two rival methodologies for consistently representing change and observable func- tions within the original phase space before evaluating the relevant philosophical implications. We will conclude with a preview of the case against symplectic re- duction being applied to canonical general relativity. (shrink)

The conventional interpretation that Pierre Duhem condemned outright any type of thought experiment in Ernst Mach’s sense should be, at least in large part, rejected. Although Duhem placed particular emphasis on the perils of thought experiments that Mach had overlooked or at least underestimated, he retained the core idea of Mach’s theory, according to which thought experiments cannot break free from the ultimate authority of real-world experiments. This similarity between Duhem’s and Mach’s views about thought experiments is not the only (...) one. Just as there was in Duhem’s criticism of “expériences fictives” a tendency leading him to give voice to one of Mach’s basic empiricist claims, so also there was in Mach’s interpretation of thought experiments a tendency in the direction of Duhem’s conventionalism. If Mach’s and Duhem’s conceptions of thought experiments are compared, there results an importantly similar, although not identical, tension that should properly be taken into account in the more general comparison between Mach and Duhem. (shrink)

The present paper studies a specific way of addressing the question whether the laws involving the basic constituents of nature are statistical. While most German physicists, above all Planck, treated the issues of determinism and causality within a Kantian framework, the tradition which I call Vienna Indeterminism began from Mach’s reinterpretation of causality as functional dependence. This severed the bond between causality and realism because one could no longer avail oneself of a priori categories as a criterion for empirical reality. (...) Hence, an independent reality criterion had to be sought, a problem which all three physicists to be studied solved in different ways that were mainly conditioned by their different concepts of probability. In order to prevent a dissipation of intuited facts, Mach had to resort to a principle of unique determination as his reality criterion, especially when discussing the Principle of Least Action. Giving theories more independence, Boltzmann understood atomism as property reduction to precisely defined theoretical entities and their interactions. While this served as a relative reality criterion, he also advocated a constructivist one because atomism was already implied by our finitary reasoning power. Finally, Exner contemplated the idea that all apparently deterministic laws are only a macroscopic limit of an irreducible indeterminism, because by adopting the frequency interpretation, observable collectives could be considered as the real basic entities. (shrink)

During the second decade of the 20th century Hans Kleinpeter, an Austrian scholar devoted to the development of the modern science, published some brief papers on Nietzsche’s thought. Kleinpeter has been one of the main upholders of Mach’s epistemology and probably the first who connected his ideas with the philosophy of Nietzsche. In his book on Der Phänomenalismus (1913) he described a new world view that arose in the 19th century, a perspective that ‒ according to him ‒ completely contrasted (...) the mechanistic and metaphysical world view of the old school of scientific inquiry. The main outcome of the scientists whose name was related with this perspective (e.g. Clifford, Maxwell, Kirchoff and, obviously, Mach himself) has been the refusal of the absolute value of any “truth”. Kleinpeter’s statements on this topic are a good example of the rising of a Scientific Philosophy, whose development involved many scientists and thinkers that later set up the Verein Ernst Mach and the Wiener Kreis. On the other hand, his interest on Nietzsche is a relevant case of reception of the latter’s thought, that Kleinpeter puts into the context of the contemporary epistemology. In fact, he considers Nietzsche as one of the main upholders of the phenomenalistic world view, and states that he «took part at the same renewal of philosophical investigation that arose from the latest results of scientific inquiry» during the 19th century. A renewal whose main outcomes has been presented by John Stallo in his book on The Concepts and Theories of Modern Physics (1881), which Kleinpeter translated in German and published in 1901. According to Kleinpeter, in Nietzsche’s writings (mostly unpublished) one can find a theory of knowledge quite close to the one presented by both Mach and the new born Pragmatism, i.e. the complete refusal of an absolute truth and, therefore, the development of an antimetaphysical world view. In my paper I’ll discuss the main statements presented by Kleinpeter on this topic and show which of Nietzsche’s ideas has actually been in compliance with the main outcomes of late 19th century science. Thus, I’ll carry out a reconstruction of an unfamiliar side of the first period of reception of the philosophy of Nietzsche and its relevance to the development of a new (scientific) world view. (shrink)

This paper considers the charge that—contrary to the current widespread assumption accompanying the near-universal neglect of his work—Wilhelm Jerusalem (1854–1923) cannot count as one of the founders of the sociology of (scientific) knowledge. In order to elucidate the matter, Jerusalem’s “sociology of cognition” is here reconstructed in the context of his own work in psychology and philosophy as well as in the context of the work of some predecessors and contemporaries. It is argued that while it shows clear discontinuities with (...) the present-day understanding of the sociology of (scientific) knowledge, Jerusalem’s sociology of cognition was not only distinctive in its own day but also anticipated in nuce a much-discussed theme in current history of science. (shrink)

The late nineteenth- and early twentieth-century debate over ‘internal’ and ‘external’ relations is well explored, as far as its course in Britain is concerned. F. H. Bradley’s idealistic internalism, on the one hand, and Bertrand Russell’s realistic externalism, on the other, were at the center of this debate. Less well known, however, is that there was also a discussion about relations in the United States at the time. The central figures in this discussion were Edward Gleason Spaulding and John Dewey. (...) Like Russell, Spaulding advocated a realist-inspired externalism, while Dewey criticized this viewpoint from a pragmatist perspective. The aim of the present paper is to reconstruct the exchange between Spaulding and Dewey and to elaborate the specifics of this exchange. In doing so it will emerge, among other things, that, in contrast to Bradley’s idealist rejection of externalism, Dewey’s pragmatist attempt at a refutation was more in line with common sense and science and that Spaulding’s version of externalism differed markedly from Russell’s in its strong empirical orientation. Overall, an undeservedly forgotten chapter in the history of early twentieth-century American philosophy is revisited and reassessed. (shrink)

A new form of skepticism is described, which holds that objectivity and understanding are incompossible ideals of modern science. This is attributed to Weyl, hence its name: Weylean skepticism. Two general defeat strategies are then proposed, one of which is rejected.

Why did nineteenth‐century German historians and physicists habitually warn against vices that they believed philosophers in particular embodied: speculation, absence of common sense, and excessive systematizing? Drawing on a rich array of sources, this article interprets this vice‐charging as a rhetorical practice aimed at delineating empirical research from Naturphilosophie and Geschichtsphilosophie as practiced in the heyday of German Idealism. The strawman of “the philosopher” as invoked by historians and physicists served as a negative model for strongly empiricist scholars committed to (...) virtues like precision, thoroughness, and conscientiousness. In their historical narratives, historians and physicists consistently depicted philosophy either as a relic from the past or as a phase that they had virtuously left behind. This boundary work was central to the self‐positioning of both history and physics, which makes clear that the persona of the philosopher mattered not only to philosophers but also to scholars in adjacent disciplines. (shrink)

This paper responds to the generous comments by Alexander Klein and Cheryl Misak on my “American Pragmatism and the Vienna Circle: The Early Years”. First, besides offering some clarification of my original thesis, I argue that Jerusalem was not liable to the anti-Spencerian criticisms by James that Klein adduces in the course of defending James against the charge of psychologism. Then I investigate the impact of Wittgenstein’s Ramsey-derived pragmatism, importantly foregrounded by Misak, on the Vienna Circle and argue that it (...) was mainly limited to Schlick but not recognized as pragmatist, also leaving unaffected the impact of James’s pragmatism on Frank, Hahn and Neurath specified in my original paper. That said, Klein’s and Misak’s comments add significantly to our understanding of long-neglected transatlantic philosophical connections in the early twentieth century. (shrink)

In this contribution, I comment on Raffaella Campaner’s defense of explanatory pluralism in psychiatry (in this volume). In her paper, Campaner focuses primarily on explanatory pluralism in contrast to explanatory reductionism. Furthermore, she distinguishes between pluralists who consider pluralism to be a temporary state on the one hand and pluralists who consider it to be a persisting state on the other hand. I suggest that it would be helpful to distinguish more than those two versions of pluralism – different understandings (...) of explanatory pluralism both within philosophy of science and psychiatry – namely moderate/temporary pluralism, anything goes pluralism, isolationist pluralism, integrative pluralism and interactive pluralism. Next, I discuss the pros and cons of these different understandings of explanatory pluralism. Finally, I raise the question of how to implement or operationalize explanatory pluralism in scientific practice; how to structure the “genuine dialogue” or shape “the pluralistic attitude” Campaner is referring to. As tentative answers, I explore a question-based framework for explanatory pluralism as well as social-epistemological procedures for interaction among competing approaches and explanations. (shrink)

This paper aims at understanding the concept of convention in mechanics as a notion transferred from the field of jurisprudence. This enables us to clarify it as a new epistemic category having a pertinent role in the transformation of mechanics in the nineteenth century. Such understanding permits a separation from linguistic and arbitrary conventions, thus highlighting its epistemic features and not transforming fundamental principles into mere arbitrary agreements. After addressing the main references in the literature discussing the role of convention (...) in mechanics, we analyze its classical use as a concept originating from law. Then we explain its use by Carl G. Jacobi, Ferdinand F. Reech, and J. Henri Poincaré. Here we also show how their uses conform to the features analyzed regarding conventions in jurisprudence. Finally, we try to explain how the use of this concept, among other factors, contributed to the transformation of mechanics. (shrink)

Astroparticle physics is a recent sub-discipline of physics that emerged from early cosmic ray studies, astrophysics, and particle physics. Its theoretical foundations range from quantum field theory to general relativity, but the underlying “standard models” of cosmology and particle physics are far from being unified. The paper explores the pragmatic strategies employed in astroparticle physics in order to unify a disunified research field, the concept of observation involved in these strategies, and their relations to scientific realism.

The paper investigates the kind of dependence relation that best portrays Machian frame-dragging in general relativity. The question is tricky because frame-dragging relates local inertial frames to distant distributions of matter in a time-independent way, thus establishing some sort of non-local link between the two. For this reason, a plain causal interpretation of frame-dragging faces huge challenges. The paper will shed light on the issue by using a generalized structural equation model analysis in terms of manipulationist counterfactuals recently applied in (...) the context of metaphysical enquiry by Schaffer (2016) and Wilson (2017). The verdict of the analysis will be that frame-dragging is best understood in terms of a novel type of dependence relation that is half-way between causation and grounding. (shrink)

ArgumentEinstein's initial fame came in late 1919 with a dramatic breakthrough in his general theory of relativity. Through a remarkable confluence of events and circumstances, the mass media soon projected an image of the photogenic physicist as a bold new revolutionary thinker. With his theory of relativity Einstein had overthrown outworn ideas about space and time dating back to Newton's day, no small feat. While downplaying his reputation as a revolutionary, Einstein proved he was well cast for the role of (...) mild-mannered scientific genius. Yet fame demanded its price. Surrounded by social and economic unrest in Berlin, he was caught between two worlds, one struggling to be born, another refusing to die. Far from withdrawing, he threw himself into the political fray to become a symbol for international reconciliation during the early Weimar Republic. A decade later, his public image acquired another layer when he re-emerged as a Stoic sage and selfless humanitarian, a quasi-religious figure who saw himself as a modern-day Spinoza. Focusing on events of this period and the role of the German media in portraying them, this essay highlights the scientific and political undercurrents that drew Einstein into the public eye at a critical juncture in European history. Its broader aim is to show the import of these themes within the context of the vast literature on Einstein as well as the larger historiography of science. (shrink)

This paper is an attempt to clarify why Ludwig Boltzmann from about 1895 to 1905 seemed to adopt a series of extreme epistemological positions, ranging from phenomenalism to pragmatism, while emphatically rejecting what he called ‘metaphysics’ (by which he meant all traditional philosophy). He concluded that all philosophical differences were merely linguistic and most were ultimately meaningless. But at about the time that young Ludwig Wittgenstein began absorbing these desperate ideas (1905), Boltzmann himself under the influence of Franz Brentano seemed (...) to assume a type of representationalism about the external physical world, while in his own mind adopting it for pragmatic reasons. Why? Because “it worked”. He seems to have defended his non-representationalist Bildtheorie on similar grounds, but his suicide followed shortly (1906). (shrink)

Die Korrespondenz der beiden Physiker und Wissenschaftshistoriker Ernst Mach und Pierre Duhem ist weitgehend, vielleicht mit Ausnahme nur eines Briefes, erhalten. Neben der Dokumentation dieser historischen Zeugnisse setzt sich der Autor in diesem Aufsatz zum Ziel, die jeweiligen Motive, die Mach resp. Duhem zur Beschäftigung mit Wissenschaftsgeschichte führten und die damit verbundenen Modelle der Wissenschaftsgeschichtsentwicklung beider gegeneinander abzugrenzen. Dazu wurden insb. die in der bisher vorliegenden Sekundärliteratur zu Mach und Duhem überhaupt nicht berücksichtigte Buchbesprechung der Machschen Mechanik durch Duhem sowie (...) die ergänzenden Bemerkungen zu Duhem in späteren Auflagen der Werke und in der Korrespondenz Machs herangezogen, die eine recht detaillierte wechselseitige Kritik ihrer Methodik beinhalten. Den Abschluß meiner Betrachtungen bildet der Versuch einer Sondierung dessen, was in Duhems resp. Machs historischen Betrachtungsweisen über die nicht in Frage stehende Bedeutung als Meilensteine der Wissenschaftsgeschichtsschreibung hinaus noch heute von Relevanz ist.The preserved part of the hitherto unpublished Duhem-Mach correspondence, kept in the Archives de l'Académie des Sciences, Paris, and in the Ernst Mach Institut of the Fraunhofer Society, Freiburg im Breisgau, is documented and commented upon. Biographical, methodological, and philosophical analogies and differences between the points of view of Pierre Duhem and Ernst Mach are discussed, and a critical evaluation is given of their impact as historians of science. (shrink)

In this paper a unified theory of models and thought experiments is proposed by considering them as fictions, la Vaihinger. In order to reach this aim, the Hertzian and Botzmannian interpretation of theories as Bilder is reconsidered.

There have recently appeared claims that the influence Heinrich Hertz exerted over Wittgenstein's later work was far more abiding than previously recognised. I critically evaluate such claims by Gordon Baker and Allan Janik. I first show that Hertz was indeed concerned with the same feature, clarity, which often exercised Wittgenstein. But I then argue that Wittgenstein should not be seen as having adopted the conception of philosophical method, which Hertz deployed in The Principles of Mechanics. I show that Hertz ‘clarifies’ (...) the concept of force only in the sense that he alters that concept, and that he is not using the sort of ‘contrastive’ methods characteristic of Wittgenstein's later works. (shrink)

This paper is about the reception of Ernst Mach by Brentano and his students in Austria. I shall outline the main elements of this reception, starting with Brentano’s evaluation, in his lectures on positivism, of Mach’s theory of sensations. Secondly, I shall comment the early reception of Mach by Brentano’s pupils in Prague. The third part bears on the close relationship that Husserl established between his phenomenology and Mach’s descriptivism. I will then briefly examine Mach’s contribution to the controversy on (...) gestalt qualities. The fifth part bears on Stumpf’s debate with Mach on psychophysical relations and I shall conclude on Husserl’s criticism of Mach’s alleged logical psychologism. (shrink)

The paper presents a detailed interpretation of Edgar Wind’s Experiment and Metaphysics, a unique work on the philosophy of physics which broke with the Neo-Kantian tradition under the influence of American pragmatism. Taking up Cassirer’s interpretation of physics, Wind develops a holistic theory of the experiment and a constructivist account of empirical facts. Based on the concept of embodiment which plays a key role in Wind’s later writings on art history, he argues, however, that the outcomes of measurements are contingent. (...) He then proposes an anti-Kantian conception of a metaphysics of nature. For him, nature is an unknown totality which manifests itself in discrepancies between theories and experiment, and hence the theory formation of physics can increasingly approximate the structure of nature. It is shown that this view is ambiguous between a transcendental, metaphysical realism in Kant’s sense and an internal realism in Putnam’s sense. Wind’s central claim is that twentieth century physics offers new options for resolving Kant’s cosmological antinomies. In particular, he connected quantum indeterminism with the possibility of human freedom, a connection that Cassirer sharply opposed. (shrink)

This essay examines the provenance of a single, curious term that William James often used in connection with his own pragmatism. The term is Denkmittel, an uncommon German contraction of Denk and Mittel. James’s Central European sources for this now forgotten bit of philosophical jargon provide a small illustration of a bigger historical point that too often gets obscured. Pragmatism—James’s pragmatism, at least—was both allied with and inspired by a broader sweep of scientific instrumentalism that was already flourishing in fin (...) de siècle European philosophy. (shrink)

79. This study of the interaction between mechanics and differential geometry does not pretend to be exhaustive. In particular, there is probably more to be said about the mathematical side of the history from Darboux to Ricci and Levi Civita and beyond. Statistical mechanics may also be of interest and there is definitely more to be said about Hertz (I plan to continue in this direction) and about Poincaré's geometric and topological reasonings for example about the three body problem [Poincaré (...) 1890] (cf. also [Poincaré 1993], [Andersson 1994] and [Barrow-Green 1994]). Moreover, it would be interesting to find out how the 19th century ideas discussed here influenced the developments in the 20th century. Einstein himself is a hotly debated case. Yet, despite these shortcommings, I hope that this paper has shown that the interactions between mechanics and differential geometry is not a 20th century invention. Klein's view (see my Introduction) that Riemannian geometry grew out of mechanics, more specifically the principle of least action, cannot be maintained. On the other hand, when Riemannian geometry became known around 1870 it was immediately used in mechanics by Lipschitz. He began a continued tradition in this field, which had several elements in common with the new view of mechanics conceived by the physicists and explicitly carried out by Hertz. Before 1870 we found only scattered interactions between differential geometry and mechanics and only direct ones for systems of two or three degrees of freedom. For more degrees of freedom the geometrical ideas were in some interesting cases taken over by analogy, but these analogies did not lead to formal introduction of geometries of more than three dimensions. (shrink)

The physicist's conception of space-time underwent two major upheavals thanks to the general theory of relativity and quantum mechanics. Both theories play a fundamental role in describing the same natural world, although at different scales. However, the inconsistency between them emerged clearly as the limitation of twentieth-century physics, so a more complete description of nature must encompass general relativity and quantum mechanics as well. The problem is a theorists' problem par excellence. Experiment provide little guide, and the inconsistency mentioned above (...) is an important problem which clearly illustrates the intermingling of philosophical, mathematical, and physical thought. In fact, in order to unify general relativity with quantum field theory, it seems necessary to invent a new mathematical framework which will generalise Riemannian geometry and therefore our present conception of space and space-time. Contemporary developments in theoretical physics suggest that another revolution may be in progress, through which a new kind of geometry may enter physics, and space-time itself can be reinterpreted as an approximate, derived concept. The main purpose of this article is to show the great significance of space-time geometry in predetermining the laws which are supposed to govern the behaviour of matter, and further to support the thesis that matter itself can be built from geometry, in the sense that particles of matter as well as the other forces of nature emerges in the same way that gravity emerges from geometry. Scientific research is not a process of steady accumulation of absolute truths, which has culminated in present theories, but rather a much more dynamic kind of process in which there are no final theoretical concepts valid in unlimited domains. (David Bohm). (shrink)

Abstract Einstein intended the general theory of relativity to be a generalization of the relativity of motion and, therefore, a radical departure from previous spacetime theories. It has since become clear, however, that this intention was not fulfilled. I try to explain Einstein's misunderstanding on this point as a misunderstanding of the role that spacetime plays in physics. According to Einstein, earlier spacetime theories introduced spacetime as the unobservable cause of observable relative motions and, in particular, as the cause of (...) inertial effects of ?absolute? motion. I use a comparative analysis of Einstein and Newton to show that spacetime is not introduced as an explanation of observable effects, but rather is defined through those effects in arguments like Newton's ?water bucket? argument and Einstein's argument for special relativity. I then argue that to claim that a spacetime theory is true, or to claim that a spacetime structure is ?real?, is not to claim that a theoretical object explains the observable. Rather, it is to claim that the fundamental definitions that link spacetime structure to physical phenomena are empirically sound, i.e. that they can be successfully applied empirically. This leads to a new and clearer view of the empirical content of spacetime theories and of the meaning of ?realism? about spacetime. (shrink)

In the early eighties, philosophers of science came to the conviction that discovery and creativity form an integral part of scientific rationality. Ever since, the?positivists? have been criticised for their neglect of these topics. It is the aim of this paper to show that the positivists' approach to scientific discovery is not only much richer than is commonly recognized, but that they even defended an important thesis which some of the `friends of discovery' seem to have forgotten. Contrary to what (...) is generally accepted, I shall also show that there is no reason at all why the positivists should have ignored discovery. (shrink)

The determination of inertia by matter is looked at in general relativity, where inertia can be represented by affine or projective structure. The matter tensor T seems to underdetermine affine structure by ten degrees of freedom, eight of which can be eliminated by gauge choices, leaving two. Their physical meaning---which is bound up with that of gravitational waves and the pseudotensor t, and with the conservation of energy-momentum---is considered, along with the dependence of reality on invariance and of causal explanation (...) on conservation. (shrink)

A number of philosophers have argued that causation is not an objective feature of the microphysical world but rather is a perspectival phenomenon that holds only between “coarse-grained” entities such as those that figure in the special sciences. This view seems to pose a problem for arguments for physicalism that rely on the alleged causal completeness of physics. In this paper, I address this problem by arguing that the completeness of physics has two components, only one of which is causal. (...) These two components of completeness can be used in an argument for physicalism that is supported by strong inductive evidence even in the absence of microphysical causation. (shrink)