From Helmholtz to Schlick: The evolution of the sign-theory of perception

Efforts to trace the influence of fin de siècle neo-Kantianism on early 20th Century philosophy of science have led scholars to recognize the powerful influence on Moritz Schlick of Hermann von Helmholtz, the doyen of 19th Century physics and a leader of the zur?ck zu Kant movement. But Michael Friedman thinks that Schlick misunderstood Helmholtz' signature philosophical doctrine, the sign-theory of perception. Indeed, Friedman has argued that Schlick transformed Helmholtz' Kantian view of spatial intuition into an empiricist version of the causal theory of perception. However, it will be argued that, despite the key role the sign-theory played in his epistemology, Schlick thought the Kantianism in Helmholtz' thought was deeply flawed, rendered obsolete by philosophical insights which emerged from recent scientific developments. So even though Schlick embraced the sign-theory, he rejected Helmholtz' ideas about spatial intuition. In fact, like his teacher, Max Planck, Schlick generalized the sign-theory into a form of structural realism. At the same time, Schlick borrowed the method of concept-formation developed by the formalist mathematicians, Moritz Pasch and David Hilbert, and combined it with the conventionalism of Henri Poincaré. Then, to link formally defined concepts with experience, Schlick's introduced his ‘method of coincidences’, similar to the ‘point-coincidences’ featured in Einstein's physics. The result was an original scientific philosophy, which owed much to contemporary scientific thinkers, but little to Kant or Kantianism.     

A place for pragmatism in the dynamics of reason?

In Dynamics of Reason Michael Friedman proposes a kind of synthesis between the neokantianism of Ernst Cassirer, the logical empiricism of Rudolf Carnap, and the historicism of Thomas Kuhn. Cassirer and Carnap are to take care of the Kantian legacy of modern philosophy of science, encapsulated in the concept of the relativized a priori and the globally rational or continuous evolution of scientific knowledge, while Kuhn’s role is to ensure that the historicist character of scientific knowledge is taken seriously. More precisely, Carnapian linguistic frameworks, guarantee that the evolution of science proceeds in a rational manner locally, while Cassirer’s concept of an internally defined conceptual convergence of empirical theories provides the means to maintain the global continuity of scientific reason. In this paper it is argued that Friedman’s Neokantian account of scientific reason based on the concept of the relativized a priori underestimates the pragmatic aspects of the dynamics of scientific reason. To overcome this shortcoming, I propose to reconsider C.I. Lewis’s account of a pragmatic priori, recently modernized and elaborated by Hasok Chang. This may be considered as a first step to a dynamics of an embodied reason, less theoretical and more concrete than Friedman’s Neokantian proposal.     

De-synthesizing the relative a priori

This paper considers the question whether the notion of the relative apriori, central to Michael Friedman’s transcendentalist programme for philosophy of science, is available also to philosophers who reject appeals to a synthetic a priori. After tracing the rediscovery of the relative a priori and delineating its potential, the question is considered whether Friedman’s arguments against Quinean naturalism and Carnap’s attenuated logicism tell against a conception of philosophy as scientific metatheory that combines logical and empirical inquiries. Finding an opening here it is argued that this conception can also help itself to the notion of a relative a priori which, it is agreed, is central to historically informed theorising about science.     

Measurement,coordination, and the relativized a priori

The problem of measurement is a central issue in the epistemology and methodology of the physical sciences. In recent literature on scientific representation, large emphasis has been put on the “constitutive role” played by measurement procedures as forms of representation. Despite its importance, this issue hardly finds any mention in writings on constitutive principles, viz. in Michael Friedman׳s account of relativized a priori principles. This issue, instead, was at the heart of Reichenbach׳s analysis of coordinating principles that has inspired Friedman׳s interpretation. This paper suggests that these procedures should have a part in an account of constitutive principles of science, and that they could be interpreted following the intuition originally present (but ultimately not fully developed) in Reichenbach׳s early work.     

Another parting of the ways: Intersubjectivity and the objectivity of science

Michael Friedman defines the scientific enterprise as an ongoing project with a dynamics of reason that persists through scientific revolutions: The coherence and continuity of science owes to a communicative rationality that is operative at all times. It assures us of our shared objective world by transforming subjective points of view into intersubjectively binding agreements. Though it takes a very broad approach epistemologically, this conception of science may yet be too narrow in respect to notions of objectivity. It excludes a prominent mode of knowledge production that might be called technoscientific. This exclusion becomes particularly evident in Friedman’s discussion of Heidegger as a critic of Cassirer and Carnap and as a critic of objectivity as “universal validity” of scientific propositions. If one tends to Heidegger’s own account of objectivity, one encounters a non-propositional notion of truth. Science is seen as a technology that brings forth phenomena and processes. Accordingly, even where modern physics appears to be concerned primarily with the formulation of theories and the testing of hypotheses, it uses mathematical and representational techniques to conceive and create the modern world. And more powerfully than intersubjective agreement, technologies assure us of the unity and objectivity of our simultaneously social as well as natural world. There may be good reasons to hold fast to the close affiliation of communicative rationality, science, and enlightenment. However, to the extent that it turns a blind eye to technoscientific knowledge production and the technological character of science, a philosophy of technoscience needs to develop an alternative perspective on questions of objectivity, explanation, inference, or validation.     

The constitutive a priori and the distinction between mathematical and physical possibility

This paper is concerned with Friedman׳s recent revival of the notion of the relativized a priori. It is particularly concerned with addressing the question as to how Friedman׳s understanding of the constitutive function of the a priori has changed since his defence of the idea in his Dynamics of Reason. Friedman׳s understanding of the a priori remains influenced by Reichenbach׳s initial defence of the idea; I argue that this notion of the a priori does not naturally lend itself to describing the historical development of space-time physics. Friedman׳s analysis of the role of the rotating frame thought experiment in the development of general relativity – which he suggests made the mathematical possibility of four-dimensional space-time a genuine physical possibility – has a central role in his argument. I analyse this thought experiment and argue that it is better understood by following Cassirer and placing emphasis on regulative principles. Furthermore, I argue that Cassirer׳s Kantian framework enables us to capture Friedman׳s key insights into the nature of the constitutive a priori.     

Hans Reichenbach's and C.I. Lewis's Kantian philosophies of science

Recent work in the history of philosophy of science details the Kantianism of philosophers often thought opposed to one another, e.g., Hans Reichenbach, C.I. Lewis, Rudolf Carnap, and Thomas Kuhn. Historians of philosophy of science in the last two decades have been particularly interested in the Kantianism of Reichenbach, Carnap, and Kuhn, and more recently, of Lewis. While recent historical work focuses on recovering the threatened-to-be-forgotten Kantian themes of early twentieth-century philosophy of science, we should not elide the differences between the Kantian strands running throughout this work. In this paper, I disentangle a few of these strands in the work of Reichenbach and Lewis focusing especially on their theories of relativized, constitutive a priori principles in empirical knowledge. In particular, I highlight three related differences between Reichenbach and Lewis concerning their motivations in analyzing scientific knowledge and scientific practice, their differing conceptions of constitutivity, and their relativization of constitutive a priori principles. In light of these differences, I argue Lewis's Kantianism is more similar to Kuhn's Kantianism than Reichenbach's, and so might be of more contemporary relevance to social and practice-based approaches to the philosophy of science.     

Inventing paradigms,monopoly, methodology,and mythology at ‘Chicago’: Nutter,Stigler, and Milton Friedman

This paper aims to contribute to a better understanding of the formation of the so-called Chicago-school of economics; it does so by focusing on (i) previously unpublished correspondence between George Stigler and Thomas Kuhn as well as (ii) Warren Nutter’s The Extent of Enterprise Monopoly in the United States, 1899–1939. Nutter’s book started out as a (1949) doctoral dissertation at The University of Chicago, part of Aaron Director’s Free Market Study. Besides Director, O.H. Brownlee and Milton Friedman were closely involved with supervising it. It was published by The University of Chicago Press in 1951. The book was explicitly understood as belonging to the “Chicago School” (Dow & Abernathy, 1963). But by the time of Reder’s well known (1982) review paper Nutter does not figure at all. I argue that the Stigler-Kuhn correspondence helps us better understand why Nutter disappeared from sight. More important, by contrasting the work of Nutter with that of Harberger, the episode reveals how Milton Friedman’s methodological statements became the rhetoric for a paradigm that was committed to a very different approach than the one advocated by Nutter or Friedman.     

Between Cassirer and Kuhn. Some remarks on Friedman’s relativized a priori

This paper provides a critical evaluation of Friedman’s arguments in favour of a relativized a priori resting on Cassirer’s Neo-Kantianism, Reichenbach’s and Carnap’s constitutive a priori, and finally Kuhn’s account of scientific paradigms change. The main objection concerns Cassirer’s own view of dynamic and historical moveable a priori categories, which Friedman seems to underestimate and recasts in a merely regulative function. However, Cassirer conception of a “liberalized” a priori can shed new light on the process of scientific change and his transcendental method may be considered as a still stimulating alternative to Kuhn’s and post-Kuhnian relativism in the philosophy of science.     

Helmholtz's Kant revisited (Once more). The all-pervasive nature of Helmholtz's struggle with Kant's Anschauung

In this analysis, the classical problem of Hermann von Helmholtz's (1821–1894) Kantianism is explored from a particular vantage point, that to my knowledge, has not received the attention it deserves notwithstanding its possible key role in disentangling Helmholtz's relation to Kant's critical project. More particularly, we will focus on Helmholtz's critical engagement with Kant's concept of intuition [Anschauung] and (the related issue of) his dissatisfaction with Kant's doctrinal dualism. In doing so, it soon becomes clear that both (i) crucially mediated Helmholtz's idiosyncratic appropriation and criticism of (certain aspects of) Kant's critical project, and (ii) can be considered as a common denominator in a variety of issues that are usually addressed separately under the general header of (the problem of) Helmholtz's Kantianism. The perspective offered in this analysis can not only shed interesting new light on some interpretive issues that have become commonplace in discussions on Helmholtz's Kantianism, but also offers a particular way of connecting seemingly unrelated dimensions of Helmholtz's engagement with Kant's critical project (e.g. Helmholtz's views on causality and space). Furthermore, it amounts to the rather surprising conclusion that Helmholtz's most drastic revision of Kant's project pertains to his assumption of free will as a formal condition of experience and knowledge.     

Friedman׳s thesis

This essay examines Friedman׳s recent approach to the analysis of physical theories. Friedman argues against Quine that the identification of certain principles as ‘constitutive’ is essential to a satisfactory methodological analysis of physics. I explicate Friedman׳s characterization of a constitutive principle, and I evaluate his account of the constitutive principles that Newtonian and Einsteinian gravitation presuppose for their formulation. I argue that something close to Friedman׳s thesis is defensible.     

La FAM fatale: USP9X in development and disease

Deubiquitylating enzymes (DUBs), act downstream of ubiquitylation. As such, these post-post-translational modifiers function as the final arbitrators of a protein substrate’s ubiquitylation status, thus regulating its fate. In most instances, DUBs moderate the absolute level of a substrate, its locality or activity, rather than being an “all-or-none” phenomenon. Yet, disruption of this quantitative regulation can produce dramatic qualitative differences. The ubiquitin-specific protease 9X (USP9X/FAM) is a substrate-specific DUB, which displays an extraordinarily high level of sequence conservation from Drosophila to mammals. It is primarily the recent revelations of USP9X’s pivotal role in human cancers, both as oncogene or tumour suppressor, in developmental disorders including intellectual disability, epilepsy, autism and developmental delay that has led to a subsequent re-examination of its molecular and cellular functions. Results from experimental animal models have implicated USP9X in neurodegeneration, including Parkinson’s and Alzheimer’s disease, as well as autoimmune diseases. In this review, we describe the current and accumulated knowledge on the molecular, cellular and developmental aspects of USP9X function within the context of the biological consequences during normal development and disease.     

Maxwell’s contrived analogy: An early version of the methodology of modeling

The term “analogy” stands for a variety of methodological practices all related in one way or another to the idea of proportionality. We claim that in his first substantial contribution to electromagnetism James Clerk Maxwell developed a methodology of analogy which was completely new at the time or, to borrow John North’s expression, Maxwell’s methodology was a “newly contrived analogue”. In his initial response to Michael Faraday’s experimental researches in electromagnetism, Maxwell did not seek an analogy with some physical system in a domain different from electromagnetism as advocated by William Thomson; rather, he constructed an entirely artificial one to suit his needs. Following North, we claim that the modification which Maxwell introduced to the methodology of analogy has not been properly appreciated. In view of our examination of the evidence, we argue that Maxwell gave a new meaning to analogy; in fact, it comes close to modeling in current usage.     

Sorting nexin 3 mutation impairs development and neuronal function in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis>

The sorting nexins family of proteins (SNXs) plays pleiotropic functions in protein trafficking and intracellular signaling and has been associated with several disorders, namely Alzheimer’s disease and Down’s syndrome. Despite the growing association of SNXs with neurodegeneration, not much is known about their function in the nervous system. The aim of this work was to use the nematode Caenorhabditis elegans that encodes in its genome eight SNXs orthologs, to dissect the role of distinct SNXs, particularly in the nervous system. By screening the C. elegans SNXs deletion mutants for morphological, developmental and behavioral alterations, we show here that snx-3 gene mutation leads to an array of developmental defects, such as delayed hatching, decreased brood size and life span and reduced body length. Additionally, ?snx-3 worms present increased susceptibility to osmotic, thermo and oxidative stress and distinct behavioral deficits, namely, a chemotaxis defect which is independent of the described snx-3 role in Wnt secretion. ?snx-3 animals also display abnormal GABAergic neuronal architecture and wiring and altered AIY interneuron structure. Pan-neuronal expression of C. elegans snx-3 cDNA in the ?snx-3 mutant is able to rescue its locomotion defects, as well as its chemotaxis toward isoamyl alcohol. Altogether, the present work provides the first in vivo evidence of the SNX-3 role in the nervous system.     

Galileo’s quanti: understanding infinitesimal magnitudes

In On Local Motion in the Two New Sciences, Galileo distinguishes between ‘time’ and ‘quanto time’ to justify why a variation in speed has the same properties as an interval of time. In this essay, I trace the occurrences of the word quanto to define its role and specific meaning. The analysis shows that quanto is essential to Galileo’s mathematical study of infinitesimal quantities and that it is technically defined. In the light of this interpretation of the word quanto, Evangelista Torricelli’s theory of indivisibles can be regarded as a natural development of Galileo’s insights about infinitesimal magnitudes, transformed into a geometrical method for calculating the area of unlimited plane figures.     

Structures and strategies in ancient Greek and Roman technical writing: An Introduction

Most of our knowledge of Greek and Roman scientific practice and its place in ancient culture is derived from our study of ancient texts. In the last few decades, this written evidence—ancient technical or specialist literature—has begun to be studied using tools of literary analysis to help answer questions about, for instance, how these works were composed, their authors’ intentions and the expectations of their readers.This introduction to Structures and strategies in ancient Greek and Roman technical writing provides an overview of recent scholarship in the area, and the difficulty in pinning down what ‘technical/specialist literature’ might mean in an ancient context, since Greek and Roman authors communicated scientific knowledge using a wide variety of styles and forms of text (e.g. poetry, dialogues, letters).An outline of the three sections is provided: Form as a mirror of method, in which Sabine Föllinger and Alexander Mueller explore ways in which the structures of texts by Aristotle and Plutarch may reflect methodological concerns; Authors and their implied readers, with contributions by Oliver Stoll, David Creese, Boris Dunsch and Paula Olmos, which examines what ancient texts can tell us about the place of technical knowledge in antiquity; Science and the uses of poetry, with articles by Jochen Althoff, Michael Coxhead and Laurence Totelin, and a new English translation of the Aetna poem by Harry Hine, which explores the (to us) unexpected roles of poetry in ancient scientific culture.     

Knowing what would happen: The epistemic strategies in Galileo's thought experiments

While philosophers have subjected Galileo's classic thought experiments to critical analysis, they have tended to largely ignored the historical and intellectual context in which they were deployed, and the specific role they played in Galileo's overall vision of science. In this paper I investigate Galileo's use of thought experiments, by focusing on the epistemic and rhetorical strategies that he employed in attempting to answer the question of how one can know what would happen in an imaginary scenario. Here I argue we can find three different answers to this question in Galileo later dialogues, which reflect the changing meanings of ‘experience’ and ‘knowledge’ (scientia) in the early modern period. Once we recognise that Galileo's thought experiments sometimes drew on the power of memory and the explicit appeal to ‘common experience’, while at other times, they took the form of demonstrative arguments intended to have the status of necessary truths; and on still other occasions, they were extrapolations, or probable guesses, drawn from a carefully planned series of controlled experiments, it becomes evident that no single account of the epistemological relationship between thought experiment, experience and experiment can adequately capture the epistemic variety we find Galileo's use of imaginary scenarios. To this extent, we cannot neatly classify Galileo's use of thought experiments as either ‘medieval’ or ‘early modern’, but we should see them as indicative of the complex epistemological transformations of the early seventeenth century.     

No actual measurement … was required: Maxwell and Cavendish's null method for the inverse square law of electrostatics

In 1877 James Clerk Maxwell and his student Donald MacAlister refined Henry Cavendish's 1773 null experiment demonstrating the absence of electricity inside a charged conductor. This null result was a mathematical prediction of the inverse square law of electrostatics, and both Cavendish and Maxwell took the experiment as verifying the law. However, Maxwell had already expressed absolute conviction in the law, based on results of Michael Faraday's. So, what was the value to him of repeating Cavendish's experiment? After assessing whether the law was as secure as he claimed, this paper explores its central importance to the electrical programme that Maxwell was pursuing. It traces the historical and conceptual re-orderings through which Maxwell established the law by constructing a tradition of null tests and asserting the superior accuracy of the method. Maxwell drew on his developing ‘doctrine of method’ to identify Cavendish's experiment as a member of a wider class of null methods. By doing so, he appealed to the null practices of telegraph engineers, diverted attention from the flawed logic of the method, and sought to localise issues around the mapping of numbers onto instrumental indications, on the grounds that ‘no actual measurement … was required’.