This paper concerns late 1920 s attempts to construct unitary theories of gravity and electromagnetism. A first attempt using a non-standard connection—with torsion and zero-curvature—was carried out by Albert Einstein in a number of publications that appeared between 1928 and 1931. In 1929, Tullio Levi-Civita discussed Einstein’s geometric structure and deduced a new system of differential equations in a Riemannian manifold endowed with what is nowadays known as Levi-Civita connection. He attained an important result: Maxwell’s (...) electromagnetic equations and the gravitational equations were obtained exactly, while Einstein had deduced them only as a first order approximation. A main feature of Levi-Civita’s theory is the essential use of the Ricci’s rotation coefficients, introduced by Gregorio Ricci Curbastro many years before. We trace the history of Ricci’s coefficients that are still used today, and highlight their geometric and mechanical meaning. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Bishop Berkeley Exorcises the Infinite: Fuzzy Consequences of Strict Finitism1 David M. Levy Introduction It all began simply enough when Molyneux asked the wonderful question whether a person born blind, now able to see, would recognize by sight what he knew by touch (Davis 1960). After George Berkeley elaborated an answer, that we learn to perceive by heuristics, the foundations ofcontemporarymathematics wereinruin. Contemporary mathematicians waved their hands and changed (...) the subject.2 Berkeley's answer received a much more positive response from economists. Adam Smith,in particular, seizedupon Berkeley's doctrine that welearn to perceive distance tobuild anelaborate system in which one learns to perceive one's self-interest.3 Perhaps because older histories of mathematics are a positive hindrance in helping us understand the importance of Berkeley's argument against infinitesimals,4 its consequences for economics have passed unnoticed. If infinitesimal numbers are ruled out, and we wish to maintain an algebra, then we rule out infinite numbers. This implication of Berkeley's argumenthas a dramatic implication for our understanding ofthe history ofideas about rule-directed action. Let me motivate this claim with a well-known historical problem. The social doctrine set forth by John Locke outside the Two Treatises depends critically upon individual belief about possible states of infinite pain or pleasure. The critical issue for the intolerance of atheism in Locke's system is his claim that without beUefin the infinite bliss of heaven forgone by a criminal, there is no reason to think a calculating individual will avoid crime.5 Locke's discussion is so different from the discussion of religion by David Hume and Smith. Here, questions of the substance of belief—the infinite worth of Heaven—have largely vanished.6 What happened between Locke and Hume-Smith? One answer is Pierre Bayle and Bernard Mandeville. Berkeley's doctrine that only the finite is perceived is, I think, a better answer. Out of sight, out ofmind. In this paper I propose to give a close look at the content and consequences ofBishop Berkeley's once famous Towards a New Theory ofVision. While there are other aspects ofBerkeley's work that attract Volume XVIII Number 2 511 DAVID M. LEVY attention from historians ofeconomics,7 1 shall claim that Berkeley's insight into human perception in the Theory of Vision is central to Adam Smith's attempt to found economic behaviour on the self-awareness of systematic illusion. There is no doubt that Smith finds that much ofhuman behaviour is characterized by illusion.8 The difficulty arises, or so it seems to me, from modern unwilUngness to beheve that illusion can be systematic. There are four pieces to my argument. First, we consider Berkeley's statementofwhat we shall call his doctrine ofstrict finitism in perception.9 Berkeley puts forward two postulates: 1) there exists some minimum perceptible quantity, and 2) distance is not perceived directly but by experience. Second, we define strict finitism and demonstrate that it translates into the claim that perception is fuzzy in a technical sense. If Berkeleian perception is fuzzy, then some modern criticism of Berkeley's strict finitism is based upon a simple misunderstandingofthe propertiesoffuzzyrelations. Thisis quite easy to set right. (Getting right the doctrine of those who implicitly take perception to be fuzzy—Adam Smith is my prime candidate—will be muchharder.)Third, wereconsiderBerkeley's dispute withMandeville on the role ofinfinite gain in choice. Here, we find Mandeville putting forward the Berkeleian position that if infinite amounts mattered, people would not behave as they do. Berkeley's position against Mandeville, however, seems to depend upon the supposition that infinite distance is sensible.10 Earlier, however, the position that Mandeville argued for was defended by Berkeley. Fourth, we ask why all this isn't well known. The debate between Berkeley and Mandeville has been well studied, as has been the link between Berkeley and the Scots. In fact, our work focuses on one aspect of Berkeley's work that led to his challenge of the contemporary foundations of the calculus. If sense is a matter of perception, and infinitesimals cannot be perceived, then they are quite literally nonsense. Armed with this insight, Berkeley refuted contemporary mathematics. Nevertheless, the calculus was too... (shrink)

I argue for three conclusions. First, responsibility skeptics are committed to the position that the criminal justice system should adopt a universal nonresponsibility excuse. Second, a universal nonresponsibility excuse would diminish some of our most deeply held values, further dehumanize criminals, exacerbate mass incarceration, and cause an even greater number of innocent people (nonwrongdoers) to be punished. Third, while Saul Smilansky's ‘illusionist’ response to responsibility skeptics – that even if responsibility skepticism is correct, society should maintain a responsibility‐realist/retributivist criminal justice (...) system – is generally compelling, it would not work if a majority of society were to convert, theoretically and psychologically, to responsibility skepticism. In this (highly improbable) scenario, and only in this (highly improbable) scenario, the criminal justice system would need to be reformed in such a way that it aligned with the majority's responsibility‐skeptical beliefs and attitudes. (shrink)

We investigated motor resonance in children using a priming paradigm. Participants were asked to judge the weight of an object shortly primed by a hand in an action-related posture or a non action-related one . The hand prime could belong to a child or to an adult. We found faster response times when the object was preceded by a grasp hand posture . More crucially, participants were faster when the prime was a child’s hand, suggesting that it could belong to (...) their body schema, particularly when the child’s hand was followed by a light object . A control experiment helped us to clarify the role of the hand prime. To our knowledge this is the first behavioral evidence of motor simulation and motor resonance in children. Implications of the results for the development of the sense of body ownership and for conceptual development are discussed. (shrink)

David Hume's sympathetic principle applies to physical equals. In his account, we sympathize with those like us. By contrast, Adam Smith's sympathetic principle induces equality. We consider Hume's “other rational species” problem to see whether Smith's wider sympathetic principle would alter Hume's conclusion that “superior” beings will enslave “inferior” beings. We show that Smith introduces the notion of “generosity,” which functions as if it were Hume's justice even when there is no possibility of contract.

In lieu of an abstract, here is a brief excerpt of the content:"Magic Buffalo" and Berkeley's Theory ofVision: Learning in Society David M. Levy Introduction Berkeley's Theory of Vision contains the remarkable claim that the perception ofdistance is learned by experience. This thesis is rooted in Berkeley's doctrine that the physical basic of optical perception is angular. An impression of angle? impacts upon the optic nerve. The interpretative problem confronting an individual is that of reconstructing two pieces ofinformation, distance d (...) and magnitude m, from one datum T. Let the ratio ofm/d form arctan T. How do we come to distinguish between the pair m1,d1 and the pair m2,d2 when m^d 1 = m2/d2? How do we distinguish big objects at a distance from small objects up close? The evidence Berkeley provides for this thesis is of a funny sort. He gives examples that we do, in fact, distinguish large distant objects from small near objects. Since the arctan of the pair m1, d 1 is by hypothesisthe sameas thatofthepairm2, d2thenrecognizingdistance must be alearned abihty. We cannotextractd and m from? alone. The proper interpretation ofBerkeley's philosophy ofscience is a matter of considerable debate.1 Nonetheless, as a working theorist of visual perception he is afairly simple-minded falsificationist. Here is what he says: find a person born blind who comes by surgery to see. If that person can distinguish at a glance big distant objects from small near objects, 111 amend my theory.2 The literature on Berkeley's Theory ofVision can be fairly said to bifurcate between those who "see" the argument and those who don't. Berkeley's most important eighteenth century disciple, Adam Smith, extended Berkeley's teaching to encompass the remarkable claim that we learn to perceive our economic interest (Levy 1992a, 1992b). The negative reaction to Berkeley's theory starts in 1842 with Samuel Bailey who pronounced himself mystified by the very claim that we learn to perceive distance. The debate between Bailey and John Stuart Mill, a debate which has twentieth century counterparts, has all the characteristics ofpeople talking past each other. Volume XLX Number 1 223 DAVID M. LEVY The missing social dimension The problem, as I see it, with Berkeley's proposed critical test—stipulating his own doctrine—is that a blind person would grow up in a sighted community. Perhaps, if he grew up in a blind community, and most of the community became sighted at the same time he did, all the community might be able to perceive distance. The problem with Berkeley's test is that ifhe himself is correct about the importance ofheuristics in making the visual distinctions, the fate of one individual is somewhat beside the point. One individual surely cannot create the necessary heuristics. This learning requires some evolutionary social process. Thus, while Berkeley's thesis requires some claim about some verybasicsocial epistemology(Fuller 1988), his proposed test, asking about a blind person growing up in a community silently presumed to be sighted, does not take into account the social dimension oflearning. Having said this, it is easy to think ofa better test for Berkeley's theoryofvision. Let us find an entire community where life takes place without the visual perception of great distance. Take any individual from this community and ask Berkeleian questions. Now, we know the answer becausejust such a dialogue was reported thirtyyears ago. One society which fulfils the test criterion is that ofthe BaMbuti people who lived their life in a very dense African forest. The American anthropologist Colin Turnbull took his friend from the BaMbuti, Kenge, to the top of a hill. Here is TurnbuH's famous report: Then he saw the buffalo, still grazing lazily several miles away, far downbelow. He turned to me and said, "Whatinsects are those?" At first I hardly understood; then I realized that in the forest the range of vision is so limited that there is no great need to make an automatic allowance for distance when judging size. Out here in the plains, however, Kenge was looking for the first time Over apparently unending miles of unfamiliar grasslands, with not a tree worth the name to give him any basis for comparison. The same thing happened later on... (shrink)

This invited entry offers a brief overview of criminal responsibility. -/- The first part starts with a question: is Clyde criminally responsible for killing his girlfriend Bonnie? The answer: it depends. Particular circumstances determine whether Clyde is guilty of murder, guilty of manslaughter, not guilty because he has a good excuse, or not guilty because he has a good justification. -/- The second part addresses the complicated relationship between criminal responsibility and moral responsibility. Until recently, both concepts were considered to (...) be more or less interchangeable. But there is a growing movement, which I refer to as "responsibility skepticism," which maintains that moral responsibility is either physically or metaphysically impossible. If the responsibility skeptics are right (that moral responsibility is impossible), then what are the implications for criminal responsibility and just criminal punishment? Should we abandon these as well? Or can they survive without moral responsibility? I try to answer these questions. -/- The third part addresses social causation. The criminal justice system tends to be "dispositionalist"; it tends, that is, to assume that criminal responsibility resides entirely within the defendant. Dispositionalism, however, overlooks the fact that who we are and what we do are significantly determined by environmental influences. I then try to show that this "situationist" alternative to dispositionalism should not radically alter our approach to criminal punishment. -/- The final part briefly discusses the difficulty in evaluating criminal responsibility when the defendant is both an offender and a victim - especially when the defendant is an offender *because* of his victimization. (shrink)

Euthanasia and physician assisted-suicide are terms used to describe the process in which a doctor of a sick or disabled individual engages in an activity which directly or indirectly leads to their death. This behavior is engaged by the healthcare provider based on their humanistic desire to end suffering and pain. The psychiatrist's involvement may be requested in several distinct situations including evaluation of patient capacity when an appeal for euthanasia is requested on grounds of terminal somatic illness or when (...) the patient is requesting euthanasia due to mental suffering. We compare attitudes of 49 psychiatrists towards euthanasia and assisted suicide with a group of 54 other physicians by means of a questionnaire describing different patients, who either requested physician-assisted suicide or in whom euthanasia as a treatment option was considered, followed by a set of questions relating to euthanasia implementation. When controlled for religious practice, psychiatrists expressed more conservative views regarding euthanasia than did physicians from other medical specialties. Similarly female physicians and orthodox physicians indicated more conservative views. Differences may be due to factors inherent in subspecialty education. We suggest that in light of the unique complexity and context of patient euthanasia requests, based on their training and professional expertise psychiatrists are well suited to take a prominent role in evaluating such requests to die and making a decision as to the relative importance of competing variables. (shrink)

From email to smart phones, and from social media to Google searches, digital technologies have transformed the way we learn, entertain ourselves, socialize, and work. Despite their usefulness, these technologies have often led to information overload, stress, and distraction. David M. Levy, who has lived his life between the "fast world" of high tech and the "slow world" of contemplation, offers a welcome guide to being more relaxed, attentive, and emotionally balanced while online. In a series of exercises carefully designed (...) to help readers observe and reflect on their own use, Levy has readers observe themselves while emailing and while multitasking, and also to experiment with unplugging for a specified period. (shrink)

F. A. Hayek is uniquely responsible for his fellow economists grasping the importance of the decentralization of knowledge: as Hayek shows in his pathbreaking “The Use of Knowledge in Society,” knowledge nowhere exists as a coherent whole and to pretend otherwise is a most serious error. Hayek also shares responsibility for the popularity of a strong form of the methodological individualist research program which asserts that since collectives as such have no impact on the choices of individuals, investigators ought to (...) purge any reliance on collectives from our analysis. (shrink)

George Stigler défendit deux revendications importantes. 1) Ce que disent les gens à propos des choix n’a pas d’importance. 2) Toutes les institutions sociales sont efficientes à long terme. Je démontre que la seconde proposition découle d’une considération pour la rationalité économique à laquelle s’ajoute une préférence nulle pour le temps.Il est important de constater que la désapprobation d’une préférence positive pour le temps est un aspect de la moralité traditionnelle. Cela suggère que la seconde revendication de Stigler est tributaire (...) de la proposition selon laquelle ce que disent le gens à propos des choix est extrèmement important.George Stigler defended two important claims. 1) What people say about choice does not matter. 2) All social institutions are in the long run efficient. I demonstrate that the second proposition follows from considerations of economic rationality plus zero time discounting. It is important to note that disapproval of positive time preference is an aspect of traditional morality. Thus suggests that Stigler’s second claim depends upon the proposition that what people say about choice does matter very much. (shrink)

The Virginia School's economics of natural equals makes consent critical for policy. Democracy is understood as government by discussion, not majority rule. The claim of efficiency unsupported by consent, as common in orthodox economics, appeals to social hierarchy. Politics becomes an act of exchange among equals where the economist is only entitled to offer advice to citizens, not to dictators. The foundation of natural equality and consent explains the common themes of James Buchanan and John Rawls as well as Ronald (...) Coase and the Fabian socialists. What orthodox economics treats as efficient racial discrimination violates the fair chance entitlement to which people consent in a market economy. The importance of replication stressed by Gordon Tullock, developing themes from Karl Popper, is another expression of natural equality since the foresight of replication induces care into research. The publication of previously unpublished correspondence and documentation allows the reader to judge recent controversy. (shrink)

Dynamic systems theory (DS) provides tools for exploring how simpler elements can interact to produce complex psychological configurations. It may, as Lewis demonstrates, provide means for explicating relationships between two reductionist approaches to overlapping sets of phenomena. The result is a description of psychological phenomena at a level that begins to achieve the richness we would hope to achieve in examining psychological life as it is experienced and explored in psychoanalysis.