Introduction: "Know yourself" -- The revelation of God's wisdom -- Credo ut intellegam -- Intellego ut credam -- The relationship between faith and reason -- The interventions of the Magisterium in philosophical matters -- The interaction between philosophy and theology -- Current requirements and tasks -- Conclusion.
: Although Dirac rarely participated in the interpretational debates over quantum theory, it is traditionally assumed that his views were aligned with Heisenberg and Bohr in the so-called Copenhagen-Göttingen camp. However, an unpublished—and apparently unknown—lecture of Dirac's reveals that this view is mistaken; in the famous debate between Einstein and Bohr, Dirac sided with Einstein. Surprisingly, Dirac believed that quantum mechanics was not complete, that the uncertainty principle would not survive in the future physics, and that (...) a deterministic description of the microworld would be recovered. In this paper I show how we can make sense of this unpublished lecture in the context of Dirac's broader philosophy of quantum mechanics, and how our present understanding of Dirac's philosophical views must be revised. (shrink)
This paper describes a long-standing, though little-known, debate between PaulDirac and Werner Heisenberg over the nature of scientific methodology, theory change, and intertheoretic relations. Following Heisenberg’s terminology, their disagreements can be summarized as a debate over whether the classical and quantum theories are “open” or “closed.” A close examination of this debate sheds new light on the philosophical views of two of the great founders of quantum theory.
Nous interprétons les vues philosophiques de Werner Heisenberg comme un pragmatisme et un réalisme non-métaphysique de type Wittgensteinien. La « théorie close » est une règle (concept) Wittgensteinienne. À la différence d’Alisa Bokulich qui donne raison à la position de PaulDirac sur la nature des relations entre les théories physiques différentes, nous favorisons plutôt celle de Heisenberg. Notre position interprétant Heisenberg va aussi à l’encontre de celle de Popper: le critère d’une théorie scientifique établie (close) est sa (...) non-falsifiabilité. -/- . (shrink)
Classical mechanics and quantum mechanics are two of the most successful scientific theories ever discovered, and yet how they can describe the same world is far from clear: one theory is deterministic, the other indeterministic; one theory describes a world in which chaos is pervasive, the other a world in which chaos is absent. Focusing on the exciting field of 'quantum chaos', this book reveals that there is a subtle and complex relation between classical and quantum mechanics. It challenges the (...) received view that classical and quantum mechanics are incommensurable, and revives another, largely forgotten tradition due to Niels Bohr and PaulDirac. By artfully weaving together considerations from the history of science, philosophy of science, and contemporary physics, this book offers a new way of thinking about intertheory relations and scientific explanation. It will be of particular interest to historians and philosophers of science, philosophically-inclined physicists, and interested non-specialists. (shrink)
Two hundred years ago, Friedrich Schleiermacher took critical issue with Immanuel Kant's intellectual notion of intuition as applied to human nature (Wellmon 2006). He found it necessary to modify—"hermeneutically," as he said—Kant's notion of anthropology by enabling it to include as human the new and strange human tribes Captain Cook found in the Pacific South Seas. A similar hermeneutic move is necessary if physics is to include the local contextual empirical syntheses of relativity and quantum physics. In this hermeneutical revision (...) the synthesis is formed around the notion of a Hilbert Vector Space as the universal grammar of physics, adding to it the dynamic of the Schrödinger equation, and representing empirical "observables" by projection operators that map the subspaces of definite measurable values. Among the set of observable projection operators, some pairs share the same subspace, commute with one another, and share a common laboratory setting. Other pairs do not share this property and are described as being mutually complementary. Complementary symmetries introduce into the discursive language of physics the commonsense notion of contextuality. The new synthesis, proposed by Eugene Wigner, John von Neumann, and (in his own way) PaulDirac, brought physics into the community of common language and established it as a work of general human achievement. 1. (shrink)
The theoretical physicist PaulDirac rejected, explicitly on aesthetic grounds, a successful theory known as quantum electrodynamics (QED), which is the prototype for the family of theories known as quantum field theories (QFTs). Remarkably, the theoretical physicist Steven Weinberg, also largely on aesthetic grounds, supports QED and other QFTs. In order to evaluate these opposing aesthetic views a short introduction to the physical properties of QFTs is presented together with a detailed analysis of the aesthetic claims of (...) class='Hi'>Dirac and Weinberg. It turns out that Dirac rejected QED, without regard to its success, because this theory fails to yield to what he perceived as beautiful mathematics, whereas Weinberg's support of QFTs is founded primarily on the physical concepts of the theories. In particular, he relies on symmetries that are the basis for the construction of the extremely successful current fundamental theories of particles physics. This success was decisive in leading to Weinberg's conviction of the beauty of QFTs. As a result of the evaluation of these approaches, the factors causing scientists to perceive a theory as being a fundamentally beautiful theory are discussed in detail. (shrink)
Examples of uniformly moving charge distributions that possess conserved electromagnetic stress tensors are exhibited. These constitute stable systems with covariantly characterized electromagnetic mass. This note, on a topic to which PaulDirac made a significant contribution in 1938, is dedicated to him for his 80th birthday.
Stephen Edelston Toulmin, philosopher and historian of science, pioneer in the logical analysis of substantive argumentation, was educated in physics and philosophy at Cambridge, where he studied with PaulDirac, John Wisdom and Ludwig Wittgenstein. Cambridge, Issac Newton’s university, remained his philosophical home: he always was very critical of the way that philosophy was done at The Other Place, as Oxford is known there. The only philosopher whom he really revered there was John Austin – although it is (...) necessary hastily to add that he deeply respected Gilbert Ryle and Isaiah Berlin. Like the latter, he considered himself a “public intellectual”. As such he was delighted to be invited to become a contributor to Encounter and later, from the mid-1960s a regular contributor to The New York Review of Books. He was fascinated by Wittgenstein, attending as many of his classes as he could, but had no interest in becoming close to him. Both the idea of discipleship and Wittgenstein’s dominating personally were uncongenial to him. Like Wittgenstein and Berlin he was never at home among professional philosophers . On occasion his relationships with philosophers could be stormy indeed as was the case with Sir Karl Popper and Nelson Goodman. He prided himself on being an amateur and was only mildly disturbed when “experts” chided him as a bungler. His deepest belief was that professional philosophers do not determine what the real problems of philosophy are; rather those problems arise out of conundrums in human life. That meant for him engaging in intense dialogues, with physicists, psychologists, psychoanalysts, medical doctors, lawyers, musician artists and, of course, historians of science. (shrink)
Quantum electrodynamics is the theory of electrons and other elementary charged particles, interacting through the exchange of light quanta. Albert Einstein introduced the light quantum in 1905, but for about three decades physicists applied quantum ideas mainly in theories of the structure and behavior of matter, not to electromagnetic radiation itself, which was always treated semi-classically. This began to change after 1923 with the discovery of the Compton effect and its kinematic description by Arthur Compton and Peter Debye, based on (...) the light quantum. In this paper we review the study of high-energy radiation that led to Compton's discovery. We discuss the analysis of the intensity distribution of Compton-scattered radiation that together with the ''new'' quantum theory beginning in 1925, resulted in the development, especially by Pascual Jordan and PaulDirac, of a quantum theory of electromagnetic radiation in interaction with matter. (shrink)
For more than a century the notion of a pre-established harmony between the mathematical and physical sciences has played an important role not only in the rhetoric of mathematicians and theoretical physicists, but also as a doctrine guiding much of their research. Strongly mathematized branches of physics, such as the vortex theory of atoms popular in Victorian Britain, were not unknown in the nineteenth century, but it was only in the environment of fin-de-siècle Germany that the idea of a pre-established (...) harmony really took off and became part of the mathematicians’ ideology. Important historical figures were in this respect David Hilbert, Hermann Minkowski and, somewhat later, Albert Einstein. Roughly similar ideas can be found also among British theorists, among whom Arthur Eddington, Arthur Milne, and PaulDirac are singled out. Although largely limited to the period 1870–1940, the paper also considers Max Tegmark’s recent hypothesis of the universe being a one-to-one reflection of mathematical structures. (shrink)
Everything around us is made of 'stuff', from planets, to books, to our own bodies. Whatever it is, we call it matter or material substance. It is solid; it has mass. But what is matter, exactly? We are taught in school that matter is not continuous, but discrete. As a few of the philosophers of ancient Greece once speculated, nearly two and a half thousand years ago, matter comes in 'lumps', and science has relentlessly peeled away successive layers of matter (...) to reveal its ultimate constituents.Surely, we can't keep doing this indefinitely. We imagine that we should eventually run up against some kind of ultimately fundamental, indivisible type of stuff, the building blocks from which everything in the Universe is made. The English physicist PaulDirac called this 'the dream of philosophers'. But science has discovered that the foundations of our Universe are not as solid or as certain and dependable as we might have once imagined. They are instead built from ghosts and phantoms, of a peculiar quantum kind. And, at some point on this exciting journey of scientific discovery, we lost our grip on the reassuringly familiar concept of mass.How did this happen? How did the answers to our questions become so complicated and so difficult to comprehend? In Mass Jim Baggott explains how we come to find ourselves here, confronted by a very different understanding of the nature of matter, the origin of mass, and its implications for our understanding of the material world. Ranging from the Greek philosophers Leucippus and Democritus, and their theories of atoms and void, to the development of quantum field theory and the discovery of a Higgs boson-like particle, he explores our changing understanding of the nature of matter, and the fundamental related concept of mass. (shrink)
What was René Girard’s attitude towards philosophy? What philosophers influenced him? What stance did he take in the philosophical debates of his time? What are the philosophical questions raised by René Girard’s anthropology? In this interview, Paul Dumouchel sheds light on these issues.
This major volume assembles leading scholars to address and explain the significance of Paul Ricoeur's extraordinary body of work. Ricoeur's work is of seminal importance to the development of hermeneutics, phenomenology, and ideology critique in the human sciences. Opening with three key essays from Ricoeur himself--on Europe, fragility and responsibility, and love and justice--this fascinating volume offers a tour of his work ranging across topics such as the hermeneutics of action, narrative force, and the other and deconstruction, while discussing (...) his work in the context of such contemporary thinkers as Heidegger, Levinas, Arendt, and Gadamer. Offering a very useful overview of Paul Ricoeur's enormous contribution to modern thought, Paul Ricoeur will be invaluable for students and academics across the social and human sciences and philosophy. (shrink)
Dirac’s relativistic theory of electron generally results in two possible solutions, one with positive energy and other with negative energy. Although positive energy solutions accurately represented particles such as electrons, interpretation of negative energy solution became very much controversial in the last century. By assuming the vacuum to be completely filled with a sea of negative energy electrons, Dirac tried to avoid natural transition of electron from positive to negative energy state using Pauli’s exclusion principle. However, many scientists (...) like Bohr objected to the idea of sea of electrons as it indicates infinite density of charge and electric field and consequently infinite energy. In addition, till date, there is no experimental evidence of a particle whose total energy (kinetic plus rest) is negative. In an alternative approach, Feynman, in quantum field theory, proposed that particles with negative energy are actually positive energy particles running backwards in time. This was mathematically consistent since quantum mechanical energy operator contains time in denominator and the negative sign of energy can be absorbed in it. However, concept of negative time is logically inconsistent since in this case, effect happens before the cause. To avoid above contradictions, in this paper, we try to reformulate the Dirac’s theory of electron so that neither energy needs to be negative nor the time is required to be negative. Still, in this new formulation, two different possible solutions exist for particles and antiparticles (electrons and positrons). (shrink)
In this chapter I discuss Charles Taylor's and Paul Ricoeur's theories of narrative identity and narratives as a central form of self-interpretation. Both Taylor and Ricoeur think that self-identity is a matter of culturally and socially mediated self-definitions, which are practically relevant for one's orientation in life. First, I will go through various characterisations that Ricoeur gives of his theory, and try to show to what extent they also apply to Taylor's theory. Then, I will analyse more closely Charles (...) Taylor's, and in section three, Paul Ricoeur's views on narrative identity. (shrink)
This is a short introduction to a book symposium on Paul Gowder's recent book, _The Rule of Law in thee Real World_ (Cambridge University Press, 2016). The book symposium will appear in the St. Luis University Law Journal, 62 St. Louis U. L.J., -- (2018), with commentaries on Gowder's book by colleen Murphy, Robin West, Chad Flanders, and Matthew Lister, along with replies by Paul Gowder.
The contribution focuses on philosophical issues of justice of positive law in the light of the social teaching of John Paul II. The analyses start with consideration of anthropological foundations of justice as virtue, develop with the reflexion upon justice of actions realizing justice and finally arrive at examination of the criteria of justice of law. -/- It is argued that relations between a human being and goods (ends of actions) form ontological basis of natural law and justice of (...) actions – orders and prohibitions are secondary in respect to these relations. An aim of just law (and natural law) is not preservation or restoration of abstractly understood moral order based on norms – orders and prohibitions) but integral development (good) of a person – a being possessing dignity. John Paul’s II philosophy of law takes advantage primarily of Thomas Aquinas’ approach to law and combines it with constructions which are typical for modern human rights protection. John Paul’s II conception of natural law is anthropocentric and bases on subjective rights thinking. Human dignity and human rights which derive from it provide basic criteria for the justice of law. Human rights as subjective rights disclose natural law which is understood as a set of goods for a human person. These goods are ends of actions and as such they determine actions and their forms. This point of view is compatible with Aquinas’ definition: “law is nothing but a rational plan of operation, and … the rational plan of any kind of work is derived from the end” (Summa contra gentiles, lib. 3, cap. 114, n. 5). -/- Positive (human) law which is not just has no normative power in this sense that it does not in itself provide reasons for concrete actions of a concrete actor. Sometimes there are moral reasons for following unjust law, however if its norm prescribes actions which are wrong in themselves (internally wrong) there is moral obligation to act contrary to such a legal norm. -/- Zasadniczym przedmiotem opracowania jest filozoficzna refleksja Jana Pawła II nad sprawiedliwością prawa stanowionego. Analizy przebiegają od zagadnienia antropologicznych podstaw sprawiedliwości poprzez problematykę działań realizujących sprawiedliwość do zagadnienia sprawiedliwości prawa stanowionego. Opracowanie zamykają uwagi wskazujące na kontekst teologiczny istotny dla problematyki sprawiedliwości, którego analiza wykracza jednak poza podjęte zamierzenie koncentrujące się na problematyce filozoficznoprawnej. Argumentuje się, że u podstaw tej refleksji leży namysł nad relacją człowieka do dobra, która stanowi ontologiczną podstawę prawa naturalnego i sprawiedliwości – nakazy i zakazy są wtórne wobec tej relacji. Celem prawa i sprawiedliwości jest dobro konkretnego, obdarzonego godnością człowieka, a nie np. przywracanie abstrakcyjnie pojętego porządku moralnego. Od strony konstrukcji teoretycznej, filozofia prawa Jana Pawła II jest osadzona przede wszystkim na koncepcji Tomasza z Akwinu łączonej z konstrukcjami typowymi dla współczesnej ochrony praw człowieka. To w godności i wynikających z niej prawach człowieka poszukiwać trzeba zasadniczych treściowych kryteriów sprawiedliwości prawa. Prawa człowieka jako prawa podmiotowe są podstawowym wyrazem prawa naturalnego, stanowiącego ontyczną podstawę sprawiedliwości i które pojmowane jest jako zespół dóbr dla osoby, zatem i celów kształtujących działanie. Perspektywa pojmowania prawa naturalnego jest antropocentryczna. Prawo stanowione, które nie jest sprawiedliwe, nie ma „mocy prawa”, przede wszystkim w takim sensie, że nie stanowi samo w sobie racji działania. Niekiedy, ze względów moralnych, niesprawiedliwe prawo wymaga posłuszeństwa. Jeśli jednak prawo stanowione daje uprawnienia do czynów wewnętrznie złych i nakazuje takie czyny, to nie tylko nie obowiązuje w sumieniu i nie jest racją działania, ale obowiązkiem jest postępowanie wbrew takiemu prawu. (shrink)
The existing literature on the development of recombinant DNA technology and genetic engineering tends to focus on Stanley Cohen and Herbert Boyer's recombinant DNA cloning technology and its commercialization starting in the mid-1970s. Historians of science, however, have pointedly noted that experimental procedures for making recombinant DNA molecules were initially developed by Stanford biochemist Paul Berg and his colleagues, Peter Lobban and A. Dale Kaiser in the early 1970s. This paper, recognizing the uneasy disjuncture between scientific authorship and legal (...) invention in the history of recombinant DNA technology, investigates the development of recombinant DNA technology in its full scientific context. I do so by focusing on Stanford biochemist Berg's research on the genetic regulation of higher organisms. As I hope to demonstrate, Berg's new venture reflected a mass migration of biomedical researchers as they shifted from studying prokaryotic organisms like bacteria to studying eukaryotic organisms like mammalian and human cells. It was out of this boundary crossing from prokaryotic to eukaryotic systems through virus model systems that recombinant DNA technology and other significant new research techniques and agendas emerged. Indeed, in their attempt to reconstitute 'life' as a research technology, Stanford biochemists' recombinant DNA research recast genes as a sequence that could be rewritten thorough biochemical operations. The last part of this paper shifts focus from recombinant DNA technology's academic origins to its transformation into a genetic engineering technology by examining the wide range of experimental hybridizations which occurred as techniques and knowledge circulated between Stanford biochemists and the Bay Area's experimentalists. Situating their interchange in a dense research network based at Stanford's biochemistry department, this paper helps to revise the canonized history of genetic engineering's origins that emerged during the patenting of Cohen-Boyer's recombinant DNA cloning procedures. (shrink)
Paul Boyer shared a Nobel Prize in 1997 for his work on the mechanism of ATP synthase. His earlier work, though (which contributed indirectly to his triumph), included major errors, both experimental and theoretical. Two benchmark cases offer insight into how scientists err and how they deal with error. Boyer's work also parallels and illustrates the emergence of bioenergetics in the second half of the twentieth century, rivaling achievements in evolution and molecular biology.
The Dirac δ function has solid roots in nineteenth century work in Fourier analysis and singular integrals by Cauchy and others, anticipating Dirac’s discovery by over a century, and illuminating the nature of Cauchy’s infinitesimals and his infinitesimal definition of δ.
The self-portrait of an intellectual reveals his childhood in Vienna, wounds at the Russian front in the German army, encounters with the famous, innumerable love affairs, four marriages, and refusal to accept a "petrified and tyrannical ...
Dirac’s treatment of his well known Delta function was apparently inconsistent. We show how to reconstruct his reasoning using the inconsistency-tolerant technique of Chunk and Permeate. In passing we take note of limitations and developments of that technique.
Kalam cosmological arguments have recently been the subject of criticisms, at least inter alia, by physicists---Paul Davies, Stephen Hawking---and philosophers of science---Adolf Grunbaum. In a series of recent articles, William Craig has attempted to show that these criticisms are “superficial, iII-conceived, and based on misunderstanding.” I argue that, while some of the discussion of Davies and Hawking is not philosophically sophisticated, the points raised by Davies, Hawking and Grunbaum do suffice to undermine the dialectical efficacy of kalam cosmological arguments.
The paper discusses voice as a medium of human communication through the indirect approach of listening. After designating the multifaceted nature of the voice, the author dedicates attention to Bernhard Waldenfels’ theory of the voice as developed on the basis of the phenomenology of the alien. According to Waldenfels, the polyphony of the vocal, in which the own and the alien re-sound in mutual permeation, calls for the possibility of responsive listening. In the concluding portion of the article, the author (...) takes into consideration one of the poems from the cycle “Stimmen” that Paul Celan published in the collection Sprachgitter. With regard also to Celan’s auto-poetological writings, the ensuing interpretation attempts to briefly sketch the contours of the anti-politics of voice. (shrink)
In his recently published Where the Conflict Really Lies: Science, Religion, & Naturalism 2011 Alvin Plantinga criticises Paul Draper’s evolutionary argument against theism as part of a larger project to show that evolution poses no threat to Christian belief. Plantinga focuses upon Draper’s probabilistic claim that the facts of evolution are much more probable on naturalism than on theism, and with regard to that claim makes two specific points. First, Draper’s probabilistic claim contradicts theism’s necessary falsehood; unless Draper wishes (...) to acknowledge that theism is necessarily true, his claim commits him to theism’s contingency and so sets him at odds with a mainstream that sees God’s existence as decidedly noncontingent. Second, Plantinga argues that Draper’s probabilistic claim is, even if true, overwhelmed by counterclaims about facts that are more likely on theism than naturalism. I argue this critique of Draper depends upon a serious error, and that Plantinga overlooks the full implications of his own presuppositions. Correcting these shortcomings shows that Plantinga’s own probabilistic-apologetics (e.g., the ‘Evolutionary Argument Against Naturalism’) requires theism’s contingency no less than does Draper’s atheology. (shrink)
This volume is devoted to a reappraisal of the philosophy of Paul Feyerabend. It has four aims. The first is to reassess his already well-known work from the 1960s and 1970s in light of contemporary developments in the history and philosophy of science. The second is to explore themes in his neglected later work, including recently published and previously unavailable writings. The third is to assess the contributions that Feyerabend can make to contemporary debate, on topics such as perspectivism, (...) realism, and political philosophy of science. The fourth and final aim is to reconsider Feyerabend's place within the history of philosophy of science in the light of new scholarship. (shrink)
To some, a misguided Lamarckian and a fraud, to others a martyr in the fight against Darwinism, the Viennese zoologist Paul Kammerer (1880-1926) remains one of the most controversial scientists of the early 20th century. Here his work is reconsidered in light of turn-of-the-century problems in evolutionary theory and experimental methodology, as seen from Kammerer's perspective in Vienna. Kammerer emerges not as an opponent of Darwinism, but as one would-be modernizer of the 19th-century theory, which had included a role (...) for the inheritance of acquired characteristics. Kammerer attempted a synthesis of Darwinism with genetics and the chromosome theory, while retaining the modifying effects of the environment as the main source of favorable variation, and he developed his program of experimentation to support it. Kammerer never had a regular university position, but worked at a private experimental laboratory, with sidelines as a teacher and a popular writer and lecturer. On the lecture circuit he held forth on the significance of his science for understanding and furthering cultural evolution and he satisfied his passion for the arts and performance. In his dual career as researcher and popularizer, he did not always follow academic convention. In the contentious and rapidly changing fields of heredity and evolution, some of his stances and practices, as well as his outsider status and part-Jewish background, aroused suspicion and set the stage for the scandal that ended his career and prompted his suicide. (shrink)