Jeff McMahan's impressive recent defence of the embodied mind theory of personal identity in his highly acclaimed work The Ethics of Killing has undoubtedly reawakened belief that physical continuity is a necessary component of the relation that matters in our self-interested concern for the future. My aim in this paper is to resist this belief in a somewhat roundabout way. I want to address this belief in a somewhat roundabout way by revisiting a classic defence of the belief (...) that enormous changes in the contents of a person's psychology does not preclude justified fear of future pain. I have in mind Bernard Williams' The Self and the Future (1970) in which he argues, against the psychological view, that physical continuity is necessary for survival. I examine Williams' second thought experiment which ostensibly supports that intuition and afterwards defend two related claims. First, I argue that a close examination of the second thought experiment reveals that one's prior commitments to a particular criterion of personal identity can influence one's response to that thought experiment. Second, I argue that Williams' second thought experiment is set out in questionbegging terms. I do not claim, however, that the intuition under consideration lacks justification; I only claim that Williams' second thought experiment does not provide the needed support. (shrink)

Mathematical continuity, in the technical sense, is a precisely definable mathematical notion which refers to certain properties of numbers and number sequences. The continuity of the physical world, on the other hand, is rather different from mathematical continuity, since it is a directly experienced attribute of nature and does not require, for being understood, any mathematical theory of properties of numbers.

It is well known that the process of quantization—constructing a quantum theory out of a classical theory—is not in general a uniquely determined procedure. There are many inequivalent methods that lead to different choices for what to use as our quantum theory. In this paper, I show that by requiring a condition of continuity between classical and quantum physics, we constrain and inform the quantum theories that we end up with.

개인동일성은 우리가 사람으로서 시간을 가로질러 지속하는 조건에 관한 형이상학의 오랜 논제이다. 개인동일성에 대한 지속 조건들의 문제는 ‘시간이 지남에 따른 개인동일성 문제’, 혹은 ‘지속성 질문(the Persistence question)’이라 불린다. 지속성 질문에 답하기 위한 몇 가지 시도들이 있다. 개인동일성과 관련한 지속성 질문에 대한 가장 인기 있는 답변은 심리적 연속성 견해(psychological-continuity views)이다. 이 견해는 심리주의로 알려져 있다. 이 견해에 따르면 개인의 지속은 어떤 심리적 속성들로 구성된다. 또 다른 영향력 있는 답변은 동물적-신체적 견해(brute-physical views)이다. 인간 존재를 생물학적 유기체로 보고 동물적-신체적 조건들이 인간의 지속 (...) 조건이라고 보는 이러한 입장은 우리에게 ‘애니멀리즘(animalism)’으로 알려져 있다. 본 논문은 심리적 연속성과 연결성이 우리의 지속 조건이라고 보는 심리주의와 동물적-신체적 연속성을 지속의 우선순위에 두는 애니멀리즘 혹은 생체주의의 논증들의 핵심 쟁점들을 검토하고, ‘무-사실 논제’를 통해 사실 지속성의 조건에 문제가 되는 사실이 없음을 보일 것이다. (shrink)

There is general agreement in mathematics about what continuity is. In this paper we examine how well the mathematical definition lines up with common sense notions. We use a recent paper by Hud Hudson as a point of departure. Hudson argues that two objects moving continuously can coincide for all but the last moment of their histories and yet be separated in space at the end of this last moment. It turns out that Hudson’s construction does not deliver mathematically (...) continuous motion, but the natural question then is whether there is any merit in the alternative definition of continuity that he implicitly invokes. (shrink)

One of the most puzzling features of Leibniz’s deep metaphysics is the apparent contradiction between his claims that the law of continuity holds everywhere, so that in particular, change is continuous in every monad, and that “changes are not really continuous,” since successive states contradict one another. In this paper I try to show in what sense these claims can be understood as compatible. My analysis depends crucially on Leibniz’s idea that enduring states are “vague,” and abstract away from (...) further changes occurring within them at a higher resolution—consistently with his famous doctrine of "petites perceptions." As Leibniz explains further in a recently transcribed unpublished manuscript, these changes are dense within any actual duration, which is conceived as actually divided by them into states that are syncategorematically infinite in number and unassignably small. The correspondence between these unassignably small intervals between changes and the differentials of his calculus allows processes to be conceived as continuous, despite the discontinuity of the changes that occur in actuality. (shrink)

This book presents a detailed analysis of three ancient models of spatial magnitude, time, and local motion. The Aristotelian model is presented as an application of the ancient, geometrically orthodox conception of extension to the physical world. The other two models, which represent departures from mathematical orthodoxy, are a "quantum" model of spatial magnitude, and a Stoic model, according to which limit entities such as points, edges, and surfaces do not exist in (physical) reality. The book is unique (...) in its discussion of these ancient models within the context of later philosophical, scientific, and mathematical developments. (shrink)

Einstein Versus Bohr is unlike other books on science written by experts for non-experts, because it presents the history of science in terms of problems, conflicts, contradictions, and arguments. Science normally "keeps a tidy workshop." Professor Sachs breaks with convention by taking us into the theoretical workshop, giving us a problem-oriented account of modern physics, an account that concentrates on underlying concepts and debate. The book contains mathematical explanations, but it is so-designed that the whole argument can be followed with (...) the math omitted. Professor Sachs' story begins with classical and nineteenth century physics, describes the early discoveries in particle theory, and introduces the "old" quantum theory, which evolved into the quantum mechanics of the Copenhagen School. Such important ideas as the Einstein Photon Box experiment and the Einstein-Podolsky-Rosen Paradox, and Schrodinger's Cat Paradox are clearly expounded, followed by a completely fresh explanation of relativity in conceptual terms, showing how apparent paradoxes can be removed by Einstein's own interpretation, especially that of his later years. Professor Sachs gives a detailed comparison of the fundamentals of the quantum and relativity theories, suggesting how the contradictions might be resolved. In an epilogue, he makes suggestions, with reference to religious notions, Taoism, and Buber's theory of I-Thou, for generalizing Einstein's approach beyond physics. (shrink)

This paper addresses the doubts voiced by Wigner about the physical relevance of the concept of geometrical points by exploiting some facts known to all but honored by none: Almost all real numbers are transcendental; the explicit representation of any one will require an infinite amount of physical resources. An instrument devised to measure a continuous real variable will need a continuum of internal states to achieve perfect resolution. Consequently, a laboratory instrument for measuring a continuous variable in (...) a finite time can report only a finite number of values, each of which is constrained to be a rational number. It does not matter whether the variable is classical or quantum-mechanical. Now, in von Neumann’s measurement theory (von Neumann, Mathematical Foundations of Quantum Mechanics, Princeton University Press, Princeton, [1955]), an operator A with a continuous spectrum—which has no eigenvectors—cannot be measured, but it can be approximated by operators with discrete spectra which are measurable. The measurable approximant F(A) is not canonically determined; it has to be chosen by the experimentalist. It is argued that this operator can always be chosen in such a way that Sewell’s results (Sewell in Rep. Math. Phys. 56: 271, [2005]; Sewell, Lecture given at the J.T. Lewis Memorial Conference, Dublin, [2005]) on the measurement of a hermitian operator on a finite-dimensional vector space (described in Sect. 3.2) constitute an adequate resolution of the measurement problem in this theory. From this follows our major conclusion, which is that the notion of a geometrical point is as meaningful in nonrelativistic quantum mechanics as it is in classical physics. It is necessary to be sensitive to the fact that there is a gap between theoretical and experimental physics, which reveals itself tellingly as an error inherent in the measurement of a continuous variable. (shrink)

It is commonly thought that before the introduction of quantum mechanics, determinism was a straightforward consequence of the laws of mechanics. However, around the nineteenth century, many physicists, for various reasons, did not regard determinism as a provable feature of physics. This is not to say that physicists in this period were not committed to determinism; there were some physicists who argued for fundamental indeterminism, but most were committed to determinism in some sense. However, for them, determinism was often not (...) a provable feature of physical theory, but rather an a priori principle or a methodological presupposition. Determinism was strongly connected with principles of causality and continuity and the principle of sufficient reason; this thesis examines the relevance of these principles in the history of physics. Moreover, the history of determinism in this period shows that there were essential changes in the relation between mathematics and physics: whereas in the eighteenth century, there were metaphysical arguments which lent support to differential calculus, by the early twentieth century the development of rigorous foundations of differential calculus led to concerns about its applicability in physics. The thesis consists of six papers. In the first paper, "On the origins and foundations of Laplacian determinism", I argue that Laplace, who is usually pointed out as the first major proponent of scientific determinism, did not derive his statement of determinism directly from the laws of mechanics; rather, his determinism has a background in eighteenth century Leibnizian metaphysics, and is ultimately based on the law of continuity and the principle of sufficient reason. These principles also provided a basis for the idea that one can find laws of nature in the form of differential equations which uniquely determine natural processes. In "The Norton dome and the nineteenth century foundations of determinism", I argue that an example of indeterminism in classical physics which has attracted attention in philosophy of physics in recent years, namely the Norton come, was already discussed during the nineteenth century. However, the significance which this type of indeterminism had back then is very different from the significance which the Norton dome currently has in philosophy of physics. This is explained by the fact that determinism was conceived of in an essentially different way: in particular, the nineteenth century authors who wrote about this type of indeterminism regarded determinism as an a priori principle rather than as a property of the equations of physics. In "Vital instability: life and free will in physics and physiology, 1860-1880", I show how Maxwell, Cournot, Stewart and Boussinesq used the possibility of unstable or indeterministic mechanical systems to argue that the will or a vital principle can intervene in organic processes without violating the laws of physics, so that a strictly dualist account of life and the mind is possible. Moreover, I show that their ideas can be understood as a reaction to the law of conservation of energy and to the way it was used in physiology to exclude vital and mental causes. In "The nineteenth century conflict between mechanism and irreversibility", I show that in the late nineteenth century, there was a widespread conflict between the aim of reducing physical processes to mechanics and the recognition that certain processes are irreversible. Whereas the so-called reversibility objection is known as an objection that was made to the kinetic theory of gases, it in fact appeared in a wide range of arguments, and was susceptible to very different interpretations. It was only when the project of reducing all of physics to mechanics lost favor, in the late nineteenth century, that the reversibility objection came to be used as an argument against mechanism and against the kinetic theory of gases. In "Continuity in nature and in mathematics: Boltzmann and Poincaré", I show that the development of rigorous foundations of differential calculus in the nineteenth century led to concerns about its applicability in physics: through this development, differential calculus was made independent of empirical and intuitive notions of continuity and was instead based on mathematical continuity conditions, and for Boltzmann and Poincaré, the applicability of differential calculus in physics depended on whether these continuity conditions could be given a foundation in intuition or experience. In the final paper, "Determinism around 1900", I briefly discuss the implications of the developments described in the previous two papers for the history of determinism in physics, through a discussion of determinism in Mach, Poincaré and Boltzmann. I show that neither of them regards determinism as a property of the laws of mechanics; rather, for them, determinism is a precondition for science, which can be verified to the extent that science is successful. (shrink)

The concept of genidentity has been proposed as a way to better understand identity through time, especially in physics and biology. The genidentity view is utterly anti-substantialist in so far as it suggests that the identity of X through time does not presuppose whatsoever the existence of a permanent “core” or “substrate” of X. Yet applications of this concept to real science have been scarce and unsatisfying. In this paper, our aim is to show that a well-defined concept of functional (...) genidentity can be crucial to shed light on identity through time in classical physics and especially in biology. Finally, we show that understanding identity on the basis of continuity suggests a move towards an ontology of processes. (shrink)

A book on the notion of fundamental length, covering issues in the philosophy of math, metaphysics, and the history and the philosophy of modern physics, from classical electrodynamics to current theories of quantum gravity. Published (2014) in Cambridge University Press.

Within the traditional Hilbert space formalism of quantum mechanics, it is not possible to describe a particle as possessing, simultaneously, a sharp position value and a sharp momentum value. Is it possible, though, to describe a particle as possessing just a sharp position value (or just a sharp momentum value)? Some, such as Teller, have thought that the answer to this question is No - that the status of individual continuous quantities is very different in quantum mechanics than in classical (...) mechanics. On the contrary, I shall show that the same subtle issues arise with respect to continuous quantities in classical and quantum mechanics; and that it is, after all, possible to describe a particle as possessing a sharp position value without altering the standard formalism of quantum mechanics. (shrink)

Dans l'horizon de l’étude de la philosophie naturelle d'Averroès, le nouveau travail de Ruth Glasner intituléAverroes’ Physics: a Turning Point in Medieval Natural Philosophyoccupera assurément une place de premier plan. Dans cet ouvrage, RG propose une étude analytique des trois commentaires d'Averroès à laPhysiqued'Aristote – l’Abrégé, leCommentaire Moyenet leGrand Commentaire. La force incontestable de son travail réside tout d'abord dans son approche double du texte d'Averroès, à la fois philologique et théorique. Tout au long de son analyse, ces deux aspects (...) restent intimement liés et la mobilisation des instruments philologiques n'est jamais une fin en soi. Cette analyse a en effet pour but ultime de reconstruire le système du monde tel qu'Averroès le concevait. L'enjeu fondamental de cette étude est alors de supplanter la vision d'un Averroès interprète servile de la physique aristotélicienne et de présenter sa conception de la nature comme un système cohérent, organique et original. (shrink)

This thesis looks at explanation in the natural sciences, the social sciences, and in religious reflection. Although these fields differ radically in the objects studied and the methods employed, they do evidence certain formal commonalities when one inquires into the nature of the explanatory endeavor as it is manifested in each. By exploring the links between explanations and the various contexts or disciplines in which they occur, I attempt to provide a general framework for speaking of rational explanations in these (...) diverse areas. ;In an opening chapter I consider several alternatives regarding the epistemic status of religious explanations, focusing finally on the model of "intersubjective explanation." Contemporary defenses of intersubjective religious explanation are placed within the context of the broader faith/reason debate, and a quick survey is made of recent advocates of this position. I then turn to the methodology dispute in the philosophy of the natural sciences . My aim is to mediate between purely formal analyses of explanatory structure and the more recent emphasis on contextual and pragmatic factors. ;In the social sciences, many have argued, explanation is subordinate to intuitive understanding. After tracing the explanation versus understanding debate from Dilthey to the present, I present the recent work of Jurgen Habermas as a case study in the problems of social scientific rationality. Explanations in the social sciences are rational reconstructions of human meaning contexts, and "Verstehen" is required as a precondition for material adequacy. Such explanations are linked to the individual or communal effort to "make sense" of, or bring coherence into, subjective and intersubjective "worlds." ;After an excursus on philosophical explanations and the problem of philosophical rationality, I attempt a brief phenomenology of religious beliefs as explanations. As in the social sphere, religious explanations represent the believer's attempt to "make sense" of her experience in light of a given religious tradition. Although the comprehensive nature of religious explanations makes comparisons difficult--in the limit case they verge on ineffability--the concepts of meaning and coherence allow us to speak of the rationality of religious belief without total equivocation. ;The final chapter turns to the study and evaluation of religious explanations as they occur in the discipline of theology. Under the rubric "theology as a science," I defend theology's dual status as an academic discipline and as believing reflection in the service of the religious community. Through vitally concerned with the truth of its assertions, theology also shares the goals of coherence and intersubjective criticizability with its scientific counterparts. (shrink)

The development of the notion of continuous physical quantity is traced from Aristotle to Aquinas to Suarez. It is concluded that Aristotle’s divisibility definition fails to excavate the ontological core of material quantification. Although the basic germ of the solution to the problem is discovered in Aquinas, it is Suarez who fully articulates the essence of continuous physical quantity with his explicit concept of aptitudinal extension — which has crucial theological implications. Résumé Nous considérons ici le développement de (...) la notion de quantité physique continue, d’Aristote à Thomas d’Aquin à Suarez. Nous concluons que la définition d’Aristote en termes de divisibilité ne parvient pas à dégager le noyau ontologique de la quantification matérielle. Encore que le germe fondamental de la solution au problème soit découvert par Thomas d’Aquin, c’est Suarez qui articule pleinement l’essence de la quantité physique continue, grâce à son concept explicite d’extension « aptitudinale » — dont les implications théologiques sont cruciales. (shrink)

Despite several scholars referring to the relationships between the philosophy of Boltzmann and Wittgenstein, this topic is still to be explored. The aim of this paper is to analyse the similarities between their views on mathematical continuum and on the meaning of physical theories and phenomenological states of affairs. In several arguments, they both aim to achieve a similar task: by clarifying the meaning of theories in their concrete use, both authors persuade the reader to abandon an apparently intuitive (...) way of thinking in order to overcome theoretical problems by dissolving them. (shrink)

Since his Metaphysische Anfangsgründe der Naturwissenschaft was first published in 1786, controversy has surrounded Immanuel Kant’s conception of matter. In particular, the justification for both his dynamical theory of matter and the related dismissal of mechanical philosophy are obscure. In this paper, I address these longstanding issues and establish that Kant’s dynamism rests upon Leibnizian, metaphysical commitments held by Kant from his early pre-Critical texts on natural philosophy to his major critical works. I demonstrate that, throughout his corpus and inspired (...) by Leibniz, Kant endorses the a priori law of continuity of alteration as a truth of metaphysics, according to which all alterations in experience must occur gradually through all intervening degrees. The principle thus legislates against mechanical philosophy’s absolutely impenetrable atoms, as they would would involve instantaneous changes of velocity in impact. This reveals the metaphysical incoherencies in mechanical philosophy and leaves Kant’s own dynamical theory of matter, grounded on material forces, as the only viable approach to physical explanation. Subsequently, I demonstrate that Kant nevertheless made conceptual space in his system for the theoretical consideration of mechanical explanations, which makes manifest one of the positive roles that the faculty of reason can play with respect to natural science. (shrink)

Aristotle argues that time depends on soul to count it, but adds that motion, which makes time what it is, may be independent of soul. The claim that time depends on soul or mind implies that there is at least one measurable property of natural beings that exists because of the mind’s activity. This paper argues that for Aristotle time depends partly on soul, but more importantly on motion, which defines a continuum. This argument offers a robust metaphysics of time. (...) In contrast to modern philosophy of physics, for Aristotle the continuum of motion is prior in being to time, while time is a hybrid of the real continuum of motion and the activity of mind. (shrink)

I examine the reasons Aristotle presents in Physics VIII 8 for denying a crucial assumption of Zeno’s dichotomy paradox: that every motion is composed of sub-motions. Aristotle claims that a unified motion is divisible into motions only in potentiality (δυνάμει). If it were actually divided at some point, the mobile would need to have arrived at and then have departed from this point, and that would require some interval of rest. Commentators have generally found Aristotle’s reasoning unconvincing. Against David Bostock (...) and Richard Sorabji, inter alia, I argue that Aristotle offers a plausible and internally consistent response to Zeno. I defend Aristotle’s reasoning by using his discussion of what to say about the mobile at boundary instants, transitions between change and rest. There Aristotle articulates what I call the Changes are Open, Rests are Closed Rule: what is true of something at a boundary instant is what is true of it over the time of its rest. By contrast, predications true of something over its period of change are not true of the thing at either of the boundary instants of that change. I argue that this rule issues from Aristotle’s general understanding of change, as laid out in Phys. III. It also fits well with Phys. VI, where Aristotle maintains that there is a first boundary instant included in the time of rest, but not a “first in which the mobile began to change.” I then show how this rule underlies Aristotle’s argument that a continuous motion cannot be composed of actual sub-motions. Aristotle distinguishes potential middles, points passed through en route to a terminus, from actual middles. The Changes are Open, Rests are Closed Rule only applies to actual middles, because only they are boundaries of change that the mobile must arrive at and then depart from. On my reading, Aristotle argues that the instant of arrival, the first instant at which the mobile has come to be at the actual middle, cannot belong to the time of the subsequent motion. If it did, the mobile would already be moving towards the next terminus and thus, per Phys. VI 6, would have already left. But it cannot have moved away from the midpoint at the very same moment it has arrived there. This means that the instant of arrival must be separated from the time of departure by an interval of rest. I show how Aristotle’s reasoning applies generally to rule out any continuous reflexive motion or continuous complex rectilinear motion. On my interpretation, however, the argument does not apply to every change of direction. When, as in the case of projectile motion, multiple movers and their relative powers explain why the mobile changes directions, distinct sub-motions are not involved. Aristotle holds that such motions cannot be continuous, not because they involve intervals of rest, but because they involve multiple causes of motion. My interpretation of the Changes are Open, Rests are Closed Rule allows us to make better sense of Aristotle’s argument than any previous interpretation. (shrink)

The recent proposition to eliminate eponyms from physical publications is discussed. The role of eponyms in research and education is analyzed. We show that eponyms constitute an integral part of physical texts and ensure the continuity of scientific research. Their proposed elimination is dangerous for science and the entire human culture and must be rejected.

Christopher Caudwell’s The Crisis in Physics is a stylish and readable analysis of the lines of connection between scientific theories and economic realities. Caudwell provides a trenchant critique of mechanism and positivism. In the words of J.B.S. Haldane, The Crisis in Physics offers a “quarry of ideas” for future philosophers: a wealth of insights and arguments that demands continuing critical reflection.

Here, I lay the foundations of a high-level ontology of particulars whose structuring principles differ radically from the 'continuant' vs. 'occurrent' distinction traditionally adopted in applied ontology. These principles are derived from a new analysis of the ontology of “occurring” or “happening” entities. Firstly, my analysis integrates recent work on the ontology of processes, which brings them closer to objects in their mode of existence and persistence by assimilating them to continuant particulars. Secondly, my analysis distinguishes clearly between processes and (...) events, in order to make the latter abstract objects of thought (alongside propositions). Lastly, I open my ontological inventory to properties and facts, the existence of which is commonly admitted. By giving specific roles to these primitives, the framework allows one to account for static and dynamic aspects of the physical world and for the way that subjects conceive its history: facts account for the life of substances (physical objects and processes), whereas events enable cognitive subjects to account for the life story of substances. (shrink)

Introduction: The law of causality and its methodology -- Recent causal realism in quantum physics -- The law of causality : Hume, Quine and quantum physics -- Ontological and probabilistic causalisms -- Laplacean causalism in quantum physics -- Ontological commitment in quantum physics -- Causality in some quantum experiments -- Interpretations of important results in quantum physics -- Causality in the EPR paradox: Part 1. The physics -- Causality in the EPR paradox: Part 2. The physical ontology -- Causality (...) in a new double slit experiment and in EPR -- Causality in the special theory of relativity -- Micro-physical and cosmic causal continuity -- Conclusion: Causal ubiquity in the micro-world. (shrink)

The development of rigorous foundations of differential calculus in the course of the nineteenth century led to concerns among physicists about its applicability in physics. Through this development, differential calculus was made independent of empirical and intuitive notions of continuity, and based instead on strictly mathematical conditions of continuity. However, for Boltzmann and Poincaré, the applicability of mathematics in physics depended on whether there is a basis in physics, intuition or experience for the fundamental axioms of mathematics—and this (...) meant that to determine the status of differential equations in physics, they had to consider whether there was a justification for these mathematical continuity conditions in physics. For this reason, their ideas about continuity and discreteness in nature were entangled with epistemology and philosophy of mathematics. They reached opposite conclusions: Poincaré argued that physicists must work with a continuous representation of nature, and thus with differential equations, while Boltzmann argued that physicists must ultimately take nature to be discrete. (shrink)

In this paper I argue that physics is, always was, and probably always will be voiceless with respect to tense and passage, and that, therefore, if, as I believe, tense and passage are the essence of time, physics’ contribution to our understanding of time can only be limited. The argument, in a nutshell, is that if "physics has no possibility of expression for the Now", to quote Einstein, then it cannot add anything to the study of tense and passage, and (...) specifically, cannot add anything to the debate between deniers and affirmers of the existence or reality of tense and passage. Since relativity theory did not equip physics with a new language with which to speak of tense and passage, I draw the further conclusion that relativity theory has not generated the revolution to our conception of time that is attributed to it. In the last section I discuss the motivations behind the continued but misguided attempts to integrate tense into a relativistic setting, and assess the manners in which relativity theory has nevertheless enhanced, albeit indirectly, our understanding of tense and passage. (shrink)

I defend a causal reductionist account of the nature of rates of change like velocity and acceleration. This account identifies velocity with the past derivative of position and acceleration with the future derivative of velocity. Unlike most reductionist accounts, it can preserve the role of velocity as a cause of future positions and acceleration as the effect of current forces. I show that this is possible only if all the fundamental laws are expressed by differential equations of the same order. (...) Consideration of the continuity of time explains why the differential equations are all second order. This explanation is not available on non-causal or non-reductionist accounts of rates of change. Finally, I argue that alleged counterexamples to the reductionist account involving physically impossible worlds are irrelevant to an analysis of the properties that play a causal role in the actual world. 1 Background2 Grounding3 Causation4 The Proposal5 Why No Third Derivatives?6 Why Any Derivatives?7 Counterexamples? (shrink)

Physical reality is all the reality we have, and so physical theory in the standard sense is all the ontology we need. This, at least, was an assumption taken almost universally for granted by the advocates of exact philosophy for much of the present century. Every event, it was held, is a physical event, and all structure in reality is physical structure. The grip of this assumption has perhaps been gradually weakened in recent years as far (...) as the sciences of mind are concerned. When it comes to the sciences of external reality, however, it continues to hold sway, so that contemporary philosophers B even while devoting vast amounts of attention to the language we use in describing the world of everyday experience B still refuse to see this world as being itself a proper object of theoretical concern. Here, however, we shall argue that the usual conception of physical reality as constituting a unique bedrock of objectivity reflects a rather archaic view as to the nature of physics itself and is in fact incompatible with the development of the discipline since Newton. More specifically, we shall seek to show that the world of qualitative structures, for example of colour and sound, or the commonsense world of coloured and sounding things, can be treated scientifically (ontologically) on its own terms, and that such a treatment can help us better to understand the structures both of physical reality and of cognition. (shrink)

Cet ouvrage offre aux lecteurs une série de monographies consacrées presque toutes à diverses questions de Physique quantique et de Mécanique ondulatoire. Cet ensemble d'essais étudie l'aspect vraiment nouveau que prennent dans la Physique de l'époque le traditionnel dilemme « continu ou discontinu », la classique opposition de l'élément simple et indivisible avec le continu étendu et divisible. Ces réflexions, révolutionnaires à l'époque, restent aujourd'hui encore d'une étonnante modernité. Dans la science moderne, l'élément simple et indivisible, c'est le grain, grain (...) de matière ou grain de lumière, neutron, électron ou photon. Par contre, dans les théories nouvelles comme dans les anciennes, l'étendue continue et divisible, c'est essentiellement le champ, c'est-à-dire l'ensemble des propriétés physiques qui caractérisent à chaque instant les divers points de l'espace et qui s'expriment par des fonctions généralement continues des coordonnées d'espace et de temps. Mais les conceptions antinomiques de grain et de champ doivent nécessairement en fin de compte venir à la rencontre l'une de l'autre puisqu'elles doivent trouver leur place côte à côte dans le cadre de la Physique totale. Comment les concilier? (shrink)