Nagarjuna and Quantum physics. Eastern and Western Modes of Thought. Summary. The key terms. 1. Key term: ‘Emptiness’. The Indian philosopher Nagarjuna is known in the history of Buddhism mainly by his keyword ‘sunyata’. This word is translated into English by the word ‘emptiness’. The translation and the traditional interpretations create the impression that Nagarjuna declares the objects as empty or illusionary or not real or not existing. What is the assertion and concrete statement made by this interpretation? That nothing (...) can be found, that there is nothing, that nothing exists? Was Nagarjuna denying the external world? Did he wish to refute that which evidently is? Did he want to call into question the world in which we live? Did he wish to deny the presence of things that somehow arise? My first point is the refutation of this traditional translation and interpretation. 2. Key terms: ‘Dependence’ or ‘relational view’. My second point consists in a transcription of the keyword of ‘sunyata’ by the word ‘dependence’. This is something that Nagarjuna himself has done. Now Nagarjuna’s central view can be named ‘dependence of things’. Nagarjuna is not looking for a material or immaterial object which can be declared as a fundamental reality of this world. His fundamental reality is not an object. It is a relation between objects. This is a relational view of reality. Reality is without foundation. Or: Reality has the wide open space as foundation. 3. Key terms: ‘Arm in arm’. But Nagarjuna did not stop there. He was not content to repeat this discovery of relational reality. He went on one step further indicating that what is happening between two things. He gave indications to the space between two things. He realised that not the behaviour of bodies, but the behaviour of something between them may be essential for understanding the reality. This open space is not at all empty. It is full of energy. The open space is the middle between things. Things are going arm in arm. The middle might be considered as a force that bounds men to the world and it might be seen as well as a force of liberation. It might be seen as a bondage to the infinite space. 4. Key term: Philosophy. Nagarjuna, we are told, was a Buddhist philosopher. This statement is not wrong when we take the notion ‘philosophy’ in a deep sense as a love to wisdom, not as wisdom itself. Philosophy is a way to wisdom. Where this way has an end wisdom begins and philosophy is no more necessary. A.N. Whitehead gives philosophy the commission of descriptive generalisation. We do not need necessarily a philosophical building of universal dimensions. Some steps of descriptive generalisation might be enough in order to see and understand reality. There is another criterion of Nagarjuna’s philosophy. Not his keywords ‘sunyata’ and ‘pratityasamutpada’ but his 25 philosophical examples are the heart of his philosophy. His examples are images. They do not speak to rational and conceptual understanding. They speak to our eyes. Images, metaphors, allegories or symbolic examples have a freshness which rational ideas do not possess. Buddhist dharma and philosophy is a philosophy of allegories. This kind of philosophy is not completely new and unknown to European philosophy. Since Plato’s allegory of the cave it is already a little known. The German philosopher Hans Blumenberg has underlined the importance of metaphors in European philosophy. -/-. (shrink)

1.Summary The key terms. 1. Key term: ‘Sunyata’. Nagarjuna is known in the history of Buddhism mainly by his keyword ‘sunyata’. This word is translated into English by the word ‘emptiness’. The translation and the traditional interpretations create the impression that Nagarjuna declares the objects as empty or illusionary or not real or not existing. What is the assertion and concrete statement made by this interpretation? That nothing can be found, that there is nothing, that nothing exists? Was Nagarjuna denying (...) the external world? Did he wish to refute that which evidently is? Did he want to call into question the world in which we live? Did he wish to deny the presence of things that somehow arise? My first point is the refutation of this traditional translation and interpretation. 2. Key terms: ‘Dependence’ or ‘relational view’. My second point consists in a transcription of the keyword of ‘sunyata’ by the word ‘dependence’. This is something that Nagarjuna himself has done. Now Nagarjuna’s central view can be named ‘dependence of things’. Nagarjuna is not looking for a material or immaterial object which can be declared as a fundamental reality of this world. His fundamental reality is not an object. It is a relation between objects. This is a relational view of reality. This is the heart of Nagarjuna’s ideas. In the 19th century a more or less unknown Italian philosopher, Vincenzo Goberti, spoke about relations as the mean and as bonds between things. Later, in quantum physics and in the philosophy of Alfred North Whitehead we are talking about interactions and entanglements. These ideas of relatedness or connections or entanglements in Eastern and Western modes of thought are the main idea of this essay. Not all entanglements are known. Just two examples: the nature of quantum entanglements is not known. Quantum entanglements should be faster than light. That's why Albert Einstein had some doubts. A second example: the completely unknown connections between the mind and the brain. Other examples are mysterious like the connections between birds in a flock. Some are a little known like gravitational forces. 3. Key terms: ‘Arm in arm’. But Nagarjuna did not stop there. He was not content to repeat this discovery of relational reality. He went on one step further indicating that what is happening between two things. He gave indications to the space between two things. He realized that not the behaviour of bodies, but the behaviour of something between them may be essential for understanding the reality. This open space is not at all empty. It is full of energy. The open space is the middle between things. Things are going arm in arm. The middle might be considered as a force that bounds men to the world and it might be seen as well as a force of liberation. It might be seen as a bondage to the infinite space. 4. Key term: Philosophy. Nagarjuna, we are told, was a Buddhist philosopher. This statement is not wrong when we take the notion ‘philosophy’ in a deep sense as a love to wisdom, not as wisdom itself. Philosophy is a way to wisdom. Where this way has an end wisdom begins and philosophy is no more necessary. A.N. Whitehead gives philosophy the commission of descriptive generalization. We do not need necessarily a philosophical building of universal dimensions. Some steps of descriptive generalization might be enough in order to see and understand reality. There is another criterion of Nagarjuna’s philosophy. Not his keywords ‘sunyata’ and ‘pratityasamutpada’ but his 25 philosophical examples are the heart of his philosophy. His examples are images. They do not speak to rational and conceptual understanding. They speak to our eyes. Images, metaphors, allegories or symbolic examples have a freshness which rational ideas do not possess. Buddhist dharma and philosophy is a philosophy of allegories. This kind of philosophy is not completely new and unknown to European philosophy. Since Plato’s allegory of the cave it is already a little known. (Plato 424 – 348 Befor Current Era) The German philosopher Hans Blumenberg has underlined the importance of metaphors in European philosophy. 5. Key terms: Quantum Physics. Why quantum physics? European modes of thought had no idea of the space between two this. They were bound to the ideas of substance or subject, two main metaphysical traditions of European philosophical history, two main principles. These substances and these subjects are two immaterial bodies which were considered by traditional European metaphysics as lying, as a sort of core, inside the objects or underlying the empirical reality of our world. The first European scientist who saw with his inner eye the forces between two things had been Michael Faraday (1791-1867). Faraday was an English scientist who contributed to the fields of electromagnetism. Later physicists like Albert Einstein, Niels Bohr, Erwin Schrödinger, Werner Heisenberg and others followed his view in modern physics. This is a fifth point of my work. I compare Nagarjuna with European scientific modes of thought for a better understanding of Asia. I do not compare Nagarjuna with European philosophers like Hegel, Heidegger, Wittgenstein. The principles and metaphysical foundations of physical sciences are more representative for European modes of thought than the ideas of Hegel, Heidegger and Wittgenstein and they are more precise. And slowly we are beginning to understand these principles. Let me take as an example the interpretation of quantum entanglement by the British mathematician Roger Penrose. Penrose discusses in the year of 2000 the experiences of quantum entanglement where light is separated over a distance of 100 kilometers and still remains connected in an unknown way. These are well known experiments in the last 30 years. Very strange for European modes of thought. The light should be either separated or connected. That is the expectation most European modes of thought tell us. Aristotle had been the first. Aristotle (384 - 322 Before Current Era) was a Greek philosopher, a student of Plato and a teacher of Alexander the Great. He told us the following principle as a metaphysical foundation: Either a situation exists or not. There is not a third possibility. Now listen to Roger Penrose: “Quantum entanglement is a very strange type of thing. It is somewhere between objects being separate and being in communication with each other” (Roger Penrose, The Large, the Small and the Human Mind, Cambridge University Press. 2000 page 66). This sentence of Roger Penrose is a first step of a philosophical generalization in a Whiteheadian sense. 6. Key terms: ‘The metaphysical foundations of modern science’ had been examined particularly by three European and American philosophers: E. A. Burtt, A.N. Whitehead and Hans-Georg Gadamer, by Gadamer eminently in his late writings on Heraclitus and Parmenides. I try to follow the approaches of these philosophers of relational views and of anti-substantialism. By ‘metaphysical foundations’ Edwin Arthur Burtt does not understand transcendental ideas but simply the principles that are underlying sciences. -/- 7. Key terms: ‘Complementarity’, ‘interactions’, ‘entanglements’. Since 1927 quantum physics has three key terms which give an indication to the fundamental physical reality: Complementarity, interactions and entanglement. These three notions are akin to Nagarjuna’s relational view of reality. They are akin and they are very precise, so that Buddhism might learn something from these descriptions and quantum physicists might learn from Nagarjuna’s examples and views of reality. They might learn to do a first step in a philosophical generalisation of quantum physical experiments. All of us we might learn how objects are entangled or going arm in arm. [The end of the summary.] -/- « Wenn du gerade das, wodurch auch immer du gefesselt bist, erkennst, wirst du zur Freiheit gelangen. Wenn du diesen speziellen Pfad verwirklichst, gelangst du in einem Leben zur Buddhaschaft. Deswegen verhält es sich folgendermaßen : Wenn plötzlich die Geistesregung « Begierde » enststeht, dann betrachte, ohne ihr zu folgen, direkt ihre Essenz und verweile in dieser Betrachtung, ohne Ablenkungen zuzulassen. Auf diese Weise reinigt Begierde sich selbst, ohne aufgegeben zu werden, da sie ohne Grundlage und Ursprung entsteht. Das wird « Befreiung in sich selbst », « unterscheidende ursprüngliche Weisheit » oder Buddha Amitabha » genannt ». Jigden Sumgön, Licht, das die Dunkelheit durchbricht, Otter Verlag, München 2006, Seite 47, 48 . (shrink)

The reluctant revolutionary -- The patent slave -- The golden Dane -- The quantum atom -- When Einstein met Bohr -- The prince of duality -- Spin doctors -- The quantum magician -- A late erotic outburst -- Uncertainty in Copenhagen -- Solvay 1927 -- Einstein forgets relativity -- Quantum reality -- For whom Bell's theorem tolls -- The quantum demon.

A pivotal focus of exegesis of Nāgārjuna's Mūlamadhyamakakārïkā (MMK) for the past half century has been the attempt to decipher the text's philosophy of language, and determine how this best aids us in characterizing Madhyamaka thought as a whole. In this vein, MMK 24:18 has been judged of particular weight insofar as it purportedly insists that the concepts pratītyasamutpāda (conditioned co-arising) and śūnyatā (emptiness), both indispensable to Buddhist praxis, are themselves only "nominal" or "conventional," that is, they are merely labels (...) that do not referentially signify anything that can be taken to be an ontologically ultimate reality. In various guises, as a result of this explication, Nāgārjuna's thought has been seen to embrace an overarching linguistic nominalism or conventionalism in which words, whether they are used for the purposes of theory or practice, though they serve as commonly accepted currency in the transactions of worldly business (vyavahāra), are in the end only ideas (prajñapti) or metaphysical fabrications (prapanca). This interpretation is largely due to tenaciously inaccurate translations and expositions of MMK 24:18 and their dependence on Candrakīrti's peculiar analysis of this verse in his Prasannapadā. This essay will attempt to correct both the diction of the major translations of MMK 24:18 and the fictions of nominalism and conventionalism that the consequent interpretations of this stanza have perpetuated. The argument that will be developed in the course of this essay is that Candrakīrti's reading of this verse proffers a strong form of linguistic nominalism that Nāgārjuna himself does not embrace. It will be shown, based on everything else found in the MMK, that Nāgārjuna, rather than advocating the mere nominal or conventional status of terms such as pratītyasamutpāda and sunyata, demands they be accepted as both pedagogically useful and even referentially accurate descriptions of the world as it is. (shrink)

These articles and speeches by the Nobel Prize-winning physicist date from 1934 to 1958. Rather than expositions on quantum physics, the papers are philosophical in nature, exploring the relevance of atomic physics to many areas of human endeavor. Includes an essay in which Bohr and Einstein discuss quantum and_wave equation theories. 1961 edition.

The strangeness of modern physics has sparked several popular books--such as The Tao of Physics--that explore its affinity with Eastern mysticism. But the founders of quantum mechanics were educated in the classical traditions of Western civilization and Western philosophy. In Nature Loves to Hide, physicist Shimon Malin takes readers on a fascinating tour of quantum theory--one that turns to Western philosophical thought to clarify this strange yet inescapable explanation of reality. Malin translates quantum mechanics into plain English, explaining its origins (...) and workings against the backdrop of the famous debate between Niels Bohr and the skeptical Albert Einstein. Then he moves on to build a philosophical framework that can account for the quantum nature of reality. He shows, for instance, how Platonic and Neoplatonic thought resonates with quantum theory. He draws out the linkage between the concepts of Neoplatonism and the more recent process philosophy of Alfred North Whitehead. The universe, Whitehead wrote, is an organic whole, composed not of lifeless objects, but "elementary experiences." Beginning with Whitehead's insight, Malin shows how this concept of "throbs of experience" expresses quantum reality, with its subatomic uncertainties, its constituents that are waves and also particles, its emphasis on acts of measurement. Once any educated person could explain the universe as a vast Newtonian web of cause and effect, but since quantum theory, reality again appears to be richer and more mysterious than we had thought. Writing with broad humanistic insight and deep knowledge of science, and using delightful conversations with fictional astronauts Peter and Julie to explain more difficult concepts, Shimon Malin offers a profound new understanding of the nature of reality--one that shows a deep continuity with aspects of our Western philosophical tradition going back 2500 years, and that feels more deeply satisfying, and truer, than the clockwork universe of Newton. (shrink)

Part I Introduction -/- Passion at a Distance (Don Howard) -/- Part II Philosophy, Methodology and History -/- Balancing Necessity and Fallibilism: Charles Sanders Peirce on the Status of Mathematics and its Intersection with the Inquiry into Nature (Ronald Anderson) -/- Newton’s Methodology (William Harper) -/- Whitehead’s Philosophy and Quantum Mechanics (QM): A Tribute to Abner Shimony (Shimon Malin) -/- Bohr and the Photon (John Stachel) -/- Part III Bell’s Theorem and Nonlocality A. Theory -/- Extending the Concept of (...) an “Element of Reality” to Work with Inefficient Detectors (Daniel M. Greenberger) -/- A General Proof of Nonlocality without Inequalities for Bipartite States (GianCarlo Ghirardi and Luca Marinatto) -/- On the Separability of Physical Systems (Jon P. Jarrett) -/- Bell Inequalities: Many Questions, a Few Answers (Nicolas Gisin) -/- B. Experiment -/- Do Experimental Violations of Bell Inequalities Require a Nonlocal Interpretation of Quantum Mechanics? II: Analysis a la Bell (Edward S. Fry, Xinmei Qu, and Marlan O. Scully) -/- The Physics of 2 = 1 + 1 (Yanhua Shih) -/- Part IV Probability, Uncertainty, and Stochastic Modifications of Quantum Mechanics -/- Interpretations of Probability in Quantum Mechanics: A Case of “Experimental Metaphysics” (Geoffrey Hellman) -/- “No Information Without Disturbance”: Quantum Limitations of Measurement (Paul Busch) -/- How Stands Collapse II (Philip Pearle) -/- Is There a Relation Between the Breakdown of the Superposition Principle and an Indeterminacy in the Structure of the Einsteinian Space-Time? (Andor Frenkel) -/- Indistinguishability or Stochastic Dependence? (D. Costantini and U. Garibaldi) -/- Part V Relativity -/- Plane Geometry in Spacetime (N. David Mermin) -/- The Transient nows (Steven F. Savitt) -/- Quantum in Gravity? (Michael Horne) -/- A Proposed Test of the Local Causality of Spacetime (Adrian Kent) -/- Quantum Gravity Computers: On the Theory of Computation with Indefinite Causal Structure (Lucien Hardy) -/- “Definability,” “Conventionality,” and Simultaneity in Einstein–Minkowski Space-Time (Howard Stein) -/- Part VI Concluding Words -/- Bistro Banter: A Dialogue with Abner Shimony and Lee Smolin -/- Unfinished Work: A Bequest (Abner Shimony) -/- Bibliography of Abner Shimony. (shrink)

The so-called paradoxes of quantum physics are easily disposed of as soon as one accepts that there are no such things as intrinsically existing particles and their intrinsic properties, but that both particles and properties are relational “observables.” Accordingly, quantum physics does not offer a “description of the outer world,” but rather a prescription about how to make probabilistic predictions within a participatory environment. The latter view looks quite radical with respect to standard Western Aristotelian ontology; but it looks natural (...) in the context of the Indian-Buddhist concept of Pratītyasamutpāda which underpins Śūnyatā. Special attention will then be devoted to the quantum feature of non-separability, which displays remarkable similarities with Pratītyasamutpāda. Finally, the meaning of such twofold parallel between quantum physics and Śūnyatā will be discussed. This parallel will be related to the similarity of epistemological situation between knowing a world from which we are not entirely separated and knowing oneself. (shrink)

: 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)

Nāgārjuna contends that the doctrine of Pratītyasamutpāda , properly understood, constitutes the philosophical basis for the rejection and avoidance of all metaphysical theories and concepts . The companion doctrine of "śūnyatā" constitutes the denial of metaphysical realism but does not imply an anti-realist, conventionalist view of reality . "Pratītyasamutpāda," the true doctrine or, literally, "the exact or real nature of the case," is really two-sided: it is a "causal" principle explaining the origin of all that exists, and a semantic principle (...) concerning the mutual dependency of concepts and beliefs in both the systematic and historically contingent sense. The latter implies a pragmatic approach to meaning. (shrink)

as the chief novelty in the quantum description of nature, Einstein for having found vindication in 3 relativity theory for either positivism or realism, depending upon whom one asks. Famous as is each in his own domain, they are famous also, together, for their decades-long disagreement over the future of fundamental physics, their respective embrace and rejection of quantum indeterminacy being only the most widely-known point of contention.

The objective of this article is to demonstrate how the historical debate between materialism and idealism, in the field of Philosophy, extends, in new clothes, to the field of Quantum Physics characterized by realism and anti-realism. For this, we opted for a debate, also historical, between the realism of Albert Einstein, for whom reality exists regardless of the existence of the knowing subject, and Niels Bohr, for whom we do not have access to the ultimate reality of the matter, unless (...) conditioning it to the existence of an observer endowed with rationality, position adopted in the Interpretation of Complementarity – posture that was expanded in 1935 when Bohr assumed a “relationalist” conception, according to which the quantum state is defined by the relationship between the quantum object and the entire measuring device. This is an extremely important debate, as it further consolidates the results of nascent Quantum Mechanics, guaranteeing Bohr the leadership of the orthodoxy based on the interpretation of complementarity. Here, when dealing with Quantum Theory, we will not make any distinction between the terms Quantum Physics, Quantum Theory or Quantum Mechanics. The entire discussion will be held under the name “Quantum Theory”. Theory that tries to analyze and describe the behavior of physical systems of reduced dimensions, close to the sizes of molecules, atoms and subatomic particles. We hope that the reader will appreciate the genius of these two titans in this field of Physics when they magnificently formulate the arguments that support the object of their defenses. (shrink)

The Indian philosopher Acharya Nagarjuna was the founder of the Madhyamaka school of Mahayana Buddhism and arguably the most influential Buddhist thinker after Buddha himself. Indeed, in the Tibetan and East Asian traditions, Nagarjuna is often referred to as the 'second Buddha.' His primary contribution to Buddhist thought lies is in the further development of the concept of sunyata or 'emptiness.' For Nagarjuna, all phenomena are without any svabhaba, literally 'own-nature' or 'self-nature', and thus without any underlying essence. In this (...) book, Jan Westerhoff offers a systematic account of Nagarjuna's philosophical position. He reads Nagarjuna in his own philosophical context, but he does not hesitate to show that the issues of Indian and Tibetan Buddhist philosophy have at least family resemblances to issues in European philosophy. (shrink)

Gau $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{d}$$ apāda, whilst accepting much of the argumentation and style of Nāgārjuna's philosophy, aligns himself firmly with the ātman/ svabhāvatā tradition of Vedānta; his view of ātman is inspired by an absorption of Nāgārjuna's dialectical method. For both Nāgārjuna and Gau $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{d}$$ apāda, the basis of both the Madhyamaka and Advaitic perspectives is the impossibility of change (na anyathabhāva). For Nāgārjuna this entails ni $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{h}$$ svabhāvatā, for Gau $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{d}$$ apāda it means absolute svabhāvatā. Both accept that the belief in (...) an ‘own nature’ (which amounts to all views of reality) entails a non-active, unchanging absolute. Nāgārjuna takes this as grounds for a rejection of svabhāvatā, Gau $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{d}$$ apāda accepts this as proof of its reality. The real dividing line between the two thinkers is on the question of the necessity (or not) of even positing a ‘nature’ to things. Nāgārjuna denies the possibility of an underlying and unchanging substratum behind all manifestations, Gau $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{d}$$ apāda argues that for there to be an appearance there must be a thing that appears. It is this point, the debate over ātman (svabhāva) or anātman (ni $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\cdot}$}}{h}$$ svabhāva) at its most fundamental level, that is the real dividing line between the philosophies of the Buddhist and the Advaita Vedāntin. (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)

SummaryThe Bohr‐Einstein debate on the interpretation of quantum mechanics may be viewed as a discussion on the epistemological status of knowledge gained by physics. It is shown that in fact the advent of quantum theory has led, in a new context, to an old philosophical controversy between epistemological realism and phenomenalism . An inquiry into this controversy, taking into account the contemporary understanding of quantum mechanics based on the axiomatic study of its foundations, leads to the conclusion that contrary to (...) widespread opinion, it is perfectly possible to formulate quantum mechanics in an entirely realistic manner according to the postulate of Einstein. We demonstrate that Bohr's episteme‐logy, in which the role of experimental arrangements in the physical description is taken as a starting point, does not necessarily imply phenomenlism, but may be justifiably considered as a complementary standpoint to the realistic epistemology of Einstein, which is based on the notion of a mental construction which pictures reality. (shrink)

In this paper, the main outlines of the discussions between Niels Bohr with Albert Einstein, Werner Heisenberg, and Erwin Schrödinger during 1920–1927 are treated. From the formulation of quantum mechanics in 1925–1926 and wave mechanics in 1926, there emerged Born's statistical interpretation of the wave function in summer 1926, and on the basis of the quantum mechanical transformation theory—formulated in fall 1926 by Dirac, London, and Jordan—Heisenberg formulated the uncertainty principle in early 1927. At the Volta Conference in Como in (...) September 1927 and at the fifth Solvay Conference in Brussels the following month, Bohr publicly enunciated his complementarity principle, which had been developing in his mind for several years. The Bohr-Einstein discussions about the consistency and completeness of qnautum mechanics and of physical theory as such—formally begun in October 1927 at the fifth Solvay Conference and carried on at the sixth Solvay Conference in October 1930—were continued during the next decades. All these aspects are briefly summarized. (shrink)

During meditation, consciousness/awareness is usually enhanced because of higher attention and concentration, which inter-dependently co-arise thru appropriate interactions between neural signals. Nāgārjuna rejects ‘inherent existence’ or ‘essence’ in favor of co-dependent origination (Pratītyasamutpāda), and that is also why he rejects causality; the entities that lack inherent existence dependently co-arise. Causality is a major issue in metaphysical views. The goals of this article are as follows: (I)Which entities lack ‘inherent existence’ or ‘essence’ and which ones inherently exist? (II) Do the entities (...) that lack inherent existence dependently co-arise and hence can we reject causality as in Nāgārjuna’s philosophy? (III) Do the entities that exist inherently cause entities that lack inherent existence? (IV) Do structure, function, experience, and environment cause each other? And (V)We critically analyze, extend, and examine Nāgārjuna’s philosophy of dependent co- origination in the extended Dual-Aspect Monism (eDAM) framework. Our analysis suggests that: (i) All conventional entities lack inherent existence. However, the dual-aspect unmanifested state of the primal entity (unified information field (UIF), emptiness, Śūnyatā, a neutral entity of Neutral Monism, or Brahman) inherently exists. The dual-aspect unmanifested state of UIF has (a) physical unified information field (PUIF, quantum vacuum, ‘zero- point field’/ZPF)as physical aspect and (b) unified potential consciousness information field (UPCIF) as the non-physical aspect. The subjective experiences (SEs) of objects and of the subject (self) are the excitations or modes of the UPCIF, so they are derived entities and hence they lack inherent existence. The dual-aspect unmanifested state of UIF/emptiness/Śūnyatā is fundamental and irreducible, and hence it inherently exists. (ii) The entities that lack inherent existence dependently co-arise, and hence causality for them can be rejected but instead conditions (such as efficient, percept-object, immediate, and dominant conditions) are necessary, as in Nāgārjuna’s philosophy. (iii) It is unclear that the dual-aspect primal entity UIF (Brahman/emptiness/Śūnyatā) that exists inherently cause entities that lack inherent existence. Most likely, all manifested entities inter-dependently co-arise thru natural laws built-in the UIF when necessary conditions for a manifested entity are satisfied thru interaction among relevant entities. (iv) It is unclear that structure, function, experience, and environment cause each other. A cause must, at the same time, be an effect of another cause. This implies that there is no first cause. Therefore, the structure, function, and experience inter-dependently co-arise thru co-evolution, co-development, sensorimotor co-tuning, and the interaction among relevant entities after the necessary conditions of manifestation of a specific entity are satisfied; and they are linked via conditions. (v) In the extended Dual-Aspect Monism (eDAM) framework, the physical aspect of a state of a manifested entity and that of the non-physical aspect (with functional, qualitative, cognitive, and experiential sub-aspects) of the same state of the same entity inseparably co-exist in each state of each entity at all levels. However, the degrees of manifestations of inseparable physical and non-physical aspects vary with the states, levels of entities, and contexts. Moreover, manifested entities lack inherent existence. In other words, the physical aspect and that of the non-physical aspect of manifested entities dependently co- arise, co-evolve, co-develop, and co-tuned for sensorimotor system appropriately depending on the levels of entities and contexts, which along with common “effective”information entail the inseparability of both aspects. In this sense, the symmetry between physical and non-physical aspects of a state of an entity (such as brain-mind system) is maintained, where the physical aspect (from third person perspective) does not cause the inseparable non-physical aspect (from first-person perspective) in living systems or vice- versa. (shrink)

The ArgumentThe aim of this paper is to provide a critical perspective for Einstein's opposition to the Copenhagen interpretation of quantum physics, by analyzing the ingenious rhetoric of Bohr's principle of complementarity. I argue that what Bohr presents as arguments of “inevitability” are in fact merely arguments for the consistency of the quantum-mechanical scheme. Einstein's resistance to being persuaded by this potent technique of argumentation, and his rejection of Bohr's interpretation of quantum physics, appear consequently as an eminently reasonable position (...) and not as a conservative stand, as it is often presented by the adherents of the Copenhagen orthodoxy. (shrink)

The famous EPR article of 1935 challenged the completeness of quantum mechanics and spurred decades of theoretical and experimental research into the foundations of quantum theory. A crowning achievement of this research is the demonstration that nature cannot in general consist in noncontextual pre-measurement properties that uniquely determine possible measurement outcomes, through experimental violations of Bell inequalities and Kochen-Specker theorems. In this article, I reconstruct an argument from Niels Bohr’s writings that the reality of the Einstein-Planck-de Broglie relations alone implies (...) that no such properties can exist for momentum and position measurements, show how this argument responds to the challenge of EPR on general physical grounds, and advance that this reconstruction shows that and how Bohr’s “complementarity” is a view of the objective content and logic of quantum theory. (shrink)

Linear combinations of “elements of reality,” as defined by Einstein, Podolsky, and Rosen, may not be themselves “elements of reality.” There are questions which can be formulated (and unambiguously answered) in the ordinary language of experimental physics, but cannot be represented in the mathematical framework of quantum theory in a nontrivial way.

This study posits that Bohr failed to defend the completeness of the quantum mechanical description of physical reality against Einstein–Podolsky–Rosen’s paper. Although there are many papers in the literature that focus on Bohr’s argument in his reply to the EPR paper, the purpose of the current paper is not to clarify Bohr’s argument. Instead, I contend that regardless of which interpretation of Bohr’s argument is correct, his defense of the quantum mechanical description of physical reality remained incomplete. For example, a (...) recent trend in studies of Bohr’s work is to suggest he considered the wave-function description to be epistemic. However, such an interpretation cannot be used to defend the completeness of the quantum mechanical description. (shrink)

There is unanimous agreement that Nāgārjuna (ca 150–250 AD) is the most important Buddhist philosopher after the historical Buddha himself and one of the most original and influential thinkers in the history of Indian philosophy. His philosophy of the “middle way” (madhyamaka) based around the central notion of “emptiness” (śūnyatā) influenced the Indian philosophical debate for a thousand years after his death; with the spread of Buddhism to Tibet, China, Japan and other Asian countries the writings of Nāgārjuna became an (...) indispensable point of reference for their own philosophical inquiries. A specific reading of Nāgārjuna's thought, called Prāsaṅgika-Madhyamaka, became the official philosophical position of Tibetan Buddhism which regards it as the pinnacle of philosophical sophistication up to the present day. (shrink)

There are two broad opposing classes of attitudes to reality with corresponding attitudes to knowledge. I argue that these attitudes can be compatible, and that quantum theory requires us to adopt both of them.

The Indian philosopher Acarya Nagarjuna (c. 150-250 CE) was the founder of the Madhyamaka (Middle Path) school of Mahayana Buddhism and arguably the most influential Buddhist thinker after Buddha himself. Indeed, in the Tibetan and East Asian traditions, Nagarjuna is often referred to as the "second Buddha." This book presents a survey of the whole of Nagarjuna's philosophy based on his key philosophical writings. His primary contribution to Buddhist thought lies in the further development of the concept of sunyata or (...) "emptiness." For Nagarjuna, all phenomena are without any svabhava, literally "own-nature" or "self-nature," and thus without any underlying substance. Particular emphasis is put on discussing Nagarjuna's thinking as philosophy. The present discussion shows how his thoughts on metaphysics, epistemology, the self, language, and truth present a unified theory of reality with considerable systematic appeal. The book offers a systematic account of Nagarjuna's philosophical position. It reads Nagarjuna in his own philosophical context, but also shows that the issues of Indian and Tibetan Buddhist philosophy have at least family resemblances to issues in European philosophy. (shrink)

Einstein's philosophy of physics (as clarified by Fine, Howard, and Held) was predicated on his Trennungsprinzip, a combination of separability and locality, without which he believed objectification, and thereby "physical thought" and "physical laws", to be impossible. Bohr's philosophy (as elucidated by Hooker, Scheibe, Folse, Howard, Held, and others), on the other hand, was grounded in a seemingly different doctrine about the possibility of objective knowledge, namely the necessity of classical concepts. In fact, it follows from Raggio's Theorem in algebraic (...) quantum theory that - within an appropriate class of physical theories - suitable mathematical translations of the doctrines of Bohr and Einstein are equivalent. Thus - upon our specific formalization - quantum mechanics accommodates Einstein's Trennungsprinzip if and only if it is interpreted a la Bohr through classical physics. Unfortunately, the protagonists themselves failed to discuss their differences in this constructive way, since their debate was dominated by Einstein's ingenious but ultimately flawed attempts to establish the "incompleteness" of quantum mechanics. This aspect of their debate may still be understood and appreciated, however, as reflecting a much deeper and insurmountable disagreement between Bohr and Einstein about the knowability of Nature. Using the theological controversy on the knowability of God as a analogy, we can say that Einstein was a Spinozist, whereas Bohr could be said to be on the side of Maimonides. Thus Einstein's off-the-cuff characterization of Bohr as a 'Talmudic philosopher' was spot-on. (shrink)

Niels Bohr, founding father of modern atomic physics and quantum theory, was as original a philosopher as he was a physicist. This study explores several dimensions of Bohr's vision: the formulation of quantum theory and the problems associated with its interpretation, the notions of complementarity and correspondence, the debates with Einstein about objectivity and realism, and his sense of the infinite harmony of nature. Honner focuses on Bohr's epistemological lesson, the conviction that all our description of nature is dependent on (...) the words we use and the ways we can unambiguously use them. (shrink)

Bohr's complementarity interpretation is represented as the relativization of the quantum mechanical description of a system to the maximal Boolean subalgebra (in the non-Boolean logical structure of the system) selected by a classically described experimental arrangement. Only propositions in this subalgebra have determinate truth values. The concept of a minimal revision of a Boolean subalgebra by a measurement is defined, and it is shown that the nonmaximal measurement of spin on one subsystem in the spin version of the Einstein—Podolsky—Rosen experiment (...) actually selects an appropriate maximal Boolean subalgebra ℛ′ in the logical structure of the composite system, via a minimal revision of the maximal Boolean subalgebra & associated with the preparation of the singlet spin state. This provides an explanation for the determinate truth values of propositions in ℛ′ referring to the second subsystem within the framework of the complementarity interpretation. (shrink)

Niels Bohr was born on October 7, 1885. He was one of the great innovators in physical science in the twentieth century. It so happens that 1985 also marks fifty years since the long discussions, which had begun in the 1920s between Albert Einstein and Bohr on the philosophical problems of quantum physics, attained their apogee. An article co-authored by Einstein, B. Podolsky, and N. Rosen, "Can Quantum Mechanics Be Considered a Complete Description of Physical Reality?," was published in 1935 (...) in the journal Physical Review. According to Bohr, "by virtue of its clarity and, it would seem, flawless argumentation, the work of Einstein, Podolsky, and Rosen has created excitement among physicists and played a great role in the discussion of general philosophical questions of physics." Precisely as a result of the publication of this article, the critical position of Einstein concerning quantum mechanics became known to a broader circle of physicists. In the same year, Bohr responded to Einstein and his co-authors with an article under the same title. (shrink)

At the start of the twentieth century, the first quantum revolution upset our vision of the world. New physics offered surprising realities, such as wave-particle duality, and led to major inventions: the transistor, the laser, and computer's integrated circuits. Less known is the second quantum revolution, arguably initiated in 1935 during a debate between giants Albert Einstein and Niels Bohr. This revolution is still unfolding. Its revolutionaries--including the author of this short accessible book, Nobel Prize-winning physicist Alain Aspect--explore the notion (...) of entangled particles, able to interact at seemingly impossible distances. Aspect has investigated entangled particles since the beginning of the 1980s and has helped to show how entanglement may both upend existing technologies, like cryptography, and usher in entirely new ones, like quantum computing. Explaining this physics of the future, this work tells a story of how philosophical debates can shape new realities. (shrink)

The photon box thought experiment can be considered a forerunner of the EPR-experiment: by performing suitable measurements on the box it is possible to ``prepare'' the photon, long after it has escaped, in either of two complementary states. Consistency requires that the corresponding box measurements be complementary as well. At first sight it seems, however, that these measurements can be jointly performed with arbitrary precision: they pertain to different systems (the center of mass of the box and an internal clock, (...) respectively). But this is deceptive. As we show by explicit calculation, although the relevant quantities are simultaneously measurable, they develop non-vanishing commutators when calculated back to the time of escape of the photon. This justifies Bohr's qualitative arguments in a precise way; and it illustrates how the details of the dynamics conspire to guarantee the requirements of complementarity. In addition, our calculations exhibit a ``fine structure'' in the distribution of the uncertainties over the complementary quantities: depending on when the box measurement is performed, the resulting quantum description of the photon differs. This brings us close to the argumentation of the later EPR thought experiment. (shrink)

This book recalls, for nonscientific readers, the history of quantum mechanics, the main points of its interpretation, and Einstein's objections to it, together with the responses engendered by his arguments. We point out that most popular discussions on the strange aspects of quantum mechanics ignore the fundamental fact that Einstein was correct in his insistence that the theory does not directly describe reality. While that fact does not remove these counterintuitive features, it casts them in a different light."--page vi.

In modern physics, the properties like charge, spin, etc. of elementary entities like electron, proton, photon, etc. are considered to be “intrinsic properties” of the entity. Intrinsic properties are those properties that a thing possesses, irrespective of whether or not there are other contingent things. In Buddhist philosophy especially in Mādhyamik philosophy, no such concept of “intrinsic property” or svabhāva exists. The problem of origin of the universe baffled the scientists and philosophers for many centuries. Within the framework of general (...) theory of relativity as discovered by Einstein, the origin and structure of the universe were discussed in a comprehensive manner. According to the recent formulation of cosmology, the universe originates from the fluctuations of the quantum vacuum. Vacuum in modern physics is not exactly nothing but rather a “something called nothing,” meaning that it is replete with activity governed by the principle of quantum theory. From philosophical perspective, what is significant is the division of creative conceptions into those which assume that the universe arose from “nothingness” in the strong ontological meaning of the word vs. those which lead to the conclusion that it was originated from a certain “poorer” physical reality, usually called “quantum vacuum” or space-time endowed with fluctuation. This vacuum or ontologically speaking a substratum exists which is devoid of any matter but full of activities or full of potentialities. Special theory of relativity is based on two axioms, one of which is the speed of light taken as constant and maximum. (shrink)

Reading Bohr: Physics and Philosophy offers a new perspective on Niels Bohr's interpretation of quantum mechanics as complementarity, and on the relationships between physics and philosophy in Bohr's work, which has had momentous significance for our understanding of quantum theory and of the nature of knowledge in general. Philosophically, the book reassesses Bohr's place in the Western philosophical tradition, from Kant and Hegel on. Physically, it reconsiders the main issues at stake in the Bohr-Einstein confrontation and in the ongoing debates (...) concerning quantum physics. It also devotes greater attention than in most commentaries on Bohr to the key developments and transformations of his thinking concerning complementarity. Most significant among them were those that occurred, first, under the impact of Bohr's exchanges with Einstein and, second, under the impact of developments in quantum theory itself, both quantum mechanics and quantum field theory. The importance of quantum field theory for Bohr's thinking has not been adequately addressed in the literature on Bohr, to the considerable detriment to our understanding of the history of quantum physics. Filling this lacuna is one of the main contributions of the book, which also enables us to show why quantum field theory compels us to move beyond Bohr without, however, simply leaving him behind. (shrink)

Canonical defenders of the principle of sufficient reason (PSR), such as Leibniz and Spinoza, are metaphysical foundationalists of one stripe or another. This is curious since the PSR—which says that everything has a ground, cause, or explanation—in effect, denies fundamental entities. In this paper, I explore the apparent inconsistency between metaphysical foundationalism and approaches to metaphysical system building that are driven by a commitment to the PSR. I do so by analyzing how Indian Buddhist philosophers arrive at foundationalist and anti-foundationalist (...) positions motivated by implicit commitments to different versions of the PSR. I begin by introducing the Buddhist principle of dependent origination (pratītyasamutpāda) as a proto-PSR that is restricted to causal explanation. Next, I show how Vasubandhu’s Sautrāntika Abhidharma metaphysics is shaped by a qualified commitment to both causal and metaphysical grounding versions of the PSR. I then reveal how Nāgārjuna’s Madhyamaka metaphysics is driven by an unrestricted and exceptionless commitment to causal and metaphysical grounding versions of the PSR. Finally, I consider how Nāgārjuna’s account may put him in a unique position to respond to a common contemporary objection to the PSR from necessitarianism. I conclude by addressing a competing interpretation on which Nāgārjuna is best understood as an anti-rationalist rather than an uber-rationalist, as I characterize him. (shrink)

There is confusion among scholars of Bohr as to whether he should be categorized as an instrumentalist (see Faye 1991) or a realist (see Folse 1985). I argue that Bohr is a realist, and that the confusion is due to the fact that he holds a very special view of realism, which did not coincide with the philosophers’ views. His approach was sometimes labelled instrumentalist and other times realist, because he was an instrumentalist on the theoretical level, but a realist (...) on the level of models. Such a realist position is what I call phenomenological realism. In this paper, and by taking Bohr’s debate with Einstein as a paradigm, I try to prove that Bohr was such a realist. (shrink)

This paper proposes an interpretation of Nāgārjuna’s doctrine of the two truths that considers saṃvṛti and paramārtha-satya two visions of reality on which the Buddhas, for soteriological and pedagogical reasons, build teachings of two types: respectively in agreement with (for example, the teaching of the Four Noble Truths) or in contrast to (for example, the teaching of emptiness) the category of svabhāva. The early sections of the article show to what extent the various current interpretations of the Nāgārjunian doctrine of (...) the dve satye—despite their sometimes even macroscopic differences—have a common tendency to consider the notion of śūnyatā as a teaching not based on, but equivalent to supreme truth. This equivalence—philologically questionable—leads to interpretative paths that prove inevitably aporetic: indeed, according to whether the interpretation of śūnyatā is ‘metaphysical’ or ‘anti-metaphysical’, it gives rise to readings of Nāgārjuna’s thought incompatible, respectively, with anti-metaphysical and realistic types of verses traceable in the works of the author of the Mūla-madhyamaka-kārikā (MMK). On the contrary, by giving more emphasis to the expression samupāśritya (“based on”), which recurs in MMK.24.8, and therefore, by epistemologically separating the notion of śūnyatā from the notion of paramārtha-satya (and of some of its conceptual equivalents such as nirvāṇa, tattva and dharmatā), we may obtain an interpretation—at once realistic and anti-metaphysical—of the theory of the two truths compatible with the vast majority (or even totality) of Nāgārjuna’s verses. (shrink)

The 1964 theorem of John Bell shows that no model that reproduces the predictions of quantum mechanics can simultaneously satisfy the assumptions of locality and determinism. On the other hand, the assumptions of signal locality plus predictability are also sufficient to derive Bell inequalities. This simple theorem, previously noted but published only relatively recently by Masanes, Acin and Gisin, has fundamental implications not entirely appreciated. Firstly, nothing can be concluded about the ontological assumptions of locality or determinism independently of each (...) other—it is possible to reproduce quantum mechanics with deterministic models that violate locality as well as indeterministic models that satisfy locality. On the other hand, the operational assumption of signal locality is an empirically testable (and well-tested) consequence of relativity. Thus Bell inequality violations imply that we can trust that some events are fundamentally unpredictable, even if we cannot trust that they are indeterministic. This result grounds the quantum-mechanical prohibition of arbitrarily accurate predictions on the assumption of no superluminal signalling, regardless of any postulates of quantum mechanics. It also sheds a new light on an early stage of the historical debate between Einstein and Bohr. (shrink)

According to the naturalistic normative axiology of Laudan's reticulated model of scientific change, empirical discoveries in the advance of science can provide a rational basis for axiological decisions concerning which epistemic goals scientific inquiry ought to pursue. The Bohr-Einstein debate over acceptance of quantum theory is analyzed as a case of axiological change. The participants' aims are incompatible due to different formulations of the goal of objective description, but neither doubts the realist commitment to the existence of microsystems or the (...) intention of quantum mechanics to provide knowledge of them. Thus the general aim of realism is not at issue. (shrink)

ABSTRACT The aim of this paper is to provide a sketch on the way Nāgārjuna deals with the idea of 'relation'. The concept of 'relation' as expressed in the Pāli sources is here theoretically systematized according to three patterns: 1. logical, 2. strictly subordinative existential, 3. non-strictly subordinative existential. After having discussed Nāgārjuna's acceptance and treatment of these three patterns, particular attention is paid to the non-strictly subordinative existential relation. This kind of relation is meant to describe the way the (...) factors of the conditioned co-origination are linked to each other and is exemplified by Nāgārjuna by means of the father-son bond. A possible way to explain the conditioned co-origination doctrine in the light of the father-son example is here suggested by having resource to the 'Cambridge change' theory. Even if in the Pāli Canon the non-strictly subordinative existential pattern is said to apply to all the other factors of the conditioned co-origination, there is no direct evidence that it concerns also the avidyā-saṃskāras link. It will be shown how Nāgārjuna, by applying it to the avidyā-saṃskāras link, seems to introduce a new perspective in the conditioned co-origination theory. RESUMO O objetivo deste artigo é proporcionar um esboço da maneira na qual Nāgārjuna aborda a ideia de 'relação'. O conceito de 'relação' que encontramos nas fontes pāli é aqui sistematizado teoricamente conforme três padrões: 1. lógico, 2. existencial estritamente subordinativo, 3. existencial não estritamente subordinativo. Após ter discutido a recepção e o tratamento nagarjunianos desses três padrões, este estudo dedica atenção especial à relação existencial não estritamente subordinativa. Esse tipo de relação visa descrever a maneira na qual os fatores da cooriginação condicionada estão ligados entre eles, e é tipificada por Nāgārjuna pelo exemplo da ligação pai-filho. Para explicar a doutrina da cooriginação condicionada à luz do exemplo pai-filho, um modo possível aqui sugerido é por meio do recurso à teoria do 'Cambridge change'. Embora no cânone pāli se diga que o modelo de relação existencial não estritamente subordinativa se aplique a todos os outros fatores da cooriginação condicionada, não há nenhuma evidência direta de que ele concerna também à ligação avidyā-saṃskāras. Será mostrado como Nāgārjuna, ao aplicar esse modelo à ligação avidyā-saṃskāras, pareça introduzir uma nova perspectiva na teoria da cooriginação condicionada. (shrink)

This is an exposition of what the author calls ‘non-classical epistemology’ in close relationship with the emergence and development of quantum mechanics. Guiding the reader along the meandering routes taken by the theory’s founders, Plotnitsky unfolds a nuanced presentation of the so-called ‘Copenhagen spirit’ or, more precisely, of the ideas of his central hero, Niels Bohr, taken to their logical conclusion. -/- Bohr’s inception and elaboration of his concept of complementarity, in conflict with his nemesis, Einstein, and alongside the other (...) pioneers of the quantum revolution is meticulously laid out in a thought-provoking narrative, punctuated with references to philosophers ranging from Aristotle and Hegel to Nietzsche and Deleuze, and to modern ground-breaking mathematical approaches to quantum mechanics. -/- Plotnitsky repeatedly stresses that he offers only ‘an’ interpretation, one among many, and a minority view at that. Nevertheless, it can arguably be said to constitute a most coherent ... (shrink)

This absorbing intellectual history vividly recreates the unique social, political, and philosophical milieu in which the extraordinary promise of Einstein and scientific contemporaries took root and flourished into greatness. Feuer shows us that no scientific breakthrough really happens by chance; it takes a certain intellectual climate, a decisive tension within the very fabric of society, to spur one man's potential genius into world-shaking achievement. Feuer portrays such men of high imaginative powers as Einstein, Bohr, Heisenberg, de Broglie, influenced by and (...) influencing the social worlds in which they lived. (shrink)

In what follows, I examine three main points which may help us to understand the deep nature of Einstein's objections to quantum mechanics. After having played a fundamental pioneer role in the birth of quantum physics, Einstein was, as is well known, far less enthusiastic about its constitution as a quantum mechanics and, since 1927, he constantly argued against the pretention of its founders and proponents to have settled a definitive and complete theory. I emphasize first the importance of the (...) philosophical climate, which was dominated by the Copenhagen orthodoxy and Bohr's idea of complementarity: What Einstein was primarily reluctant to was to accept the fundamental character of quantum mechanics as such, and to modify for it the basic principles of knowledge. I thus stress the main lines of Einstein's own programme in respect to quantum physics, which is to be considered in relation to his other contemporary attempts and achievements. Finally, I show how Einstein's arguments, when dealing with his objections, have been fruitful and some of them still worthy, with regard to recent developments concerning local nonseparability as well as concerning the problems of completeness and accomplishment of quantum theory. (shrink)

In 1935, Einstein, Podolsky and Rosen famously published a paper arguing for the incompleteness of quantum mechanics, using the example of two spatially separated but entangled particles. In his almost equally famous reply, Niels Bohr argued against EPR by providing a careful analysis of quantum measurements from the point of view of complementarity. Perhaps oddly, this analysis focuses on the example of a *single* particle passing through a slit. In this paper I argue that the disanalogy between the two examples (...) is only apparent, and does not constitute an obstacle in trying to understand Bohr's views on complementarity. (shrink)