Penser les fondements de l’éthique sociale dans les deux derniers siècles de la République romaine

The purpose of this article is to analyze howthe reflection on the origins of the civilization was developedin Rome, at the end of the Republic, in a city whereduring centuries, nobody tried to go beyond this point ofabsolute origin that was the foundation of the Vrbs. In orderto explore not only Cicéro’s philosophic reflection,but also his rhetorical texts, especially the De inuentione,which contains at the beginning of its first book a veryinteresting explanatory myth both on the birth civilization,and on the evolution of human institutions. BeforeCicero, the satiric poet Lucilius had tried to give a Romanadaptation of the Stoic social naturalism, by depriving itof its universalist ambition and Lucretius had an extremelydeep reflection of the evolution of the selfish instinctwhich characterizes the human beings as all the livingbeings, towards forms more and more sophisticated ofsociability. We evoke also a Roman peculiarity in the expressionof the social oikeiôsis. All this shows the densityand the variety of the Roman thought on society at theend of the Republic

Philon d’Alexandrie est-il inutilisable pour connaître Énésidème ?

La floraison d’études sur le scepticisme antique de ces dernières décennies a fait au moins une victime, à savoir Philon d’Alexandrie, auquel elles ont accordé une part de plus en plus restreinte, alors même que Philon est incontestablement celle de nos sources la plus proche d’Énésidème qui refonda le pyrrhonisme au ier siècle avant J.-C. Il importe donc d’établir quelle confiance on peut accorder à ce que Philon nous dit, en plusieurs endroits de son œuvre, du courant sceptique. On propose donc un bref status quaestionis, avant d’analyser la question des tropes. On soulève enfin le problème plus général de la technicisation croissante de la philosophie ancienne et de la place quasi hégémonique qu’occupe ac­tuellement la méthode analytique. Un auteur comme Philon est difficile à décomposer en propositions, dont on chercherait à définir les relations, et il n’a pas écrit – si l’on excepte le De aeternitate mundi, dont l’authenticité est discutée, le Probus, le De prouidentia et l’Alexander – une œuvre qui se présente comme explicitement philosophique. Il incarne donc un problème qui le dépasse : que peut faire la recherche lorsqu’elle est confrontée à tous ces textes dans lesquels la philosophie se trouve mêlée à ce qui n’est pas elle-même, qu’il s’agisse de littérature ou de religion ?The growing number of studies on ancient scepticism in the last thirty years or so have made at least one victim, Philo of Alexandria. He has drawn less and less interest, despite his being our source closest in time to Enesidemus, who led the rebirth of pyrrhonism during the 1st century B.C. It is hence important to assess the trustworthiness of several texts of Philo about scepticism. This paper offers a brief state of the art before focusing on Philo’s testimony about Enesidemus’ “ten modes”. It then raises the more general problem of the growing technicity of the history of ancient philosophy and the dominant role played today by the analytic method. Philo’s texts can hardly be reduced to a set of propositions combined into an argument. His works do not even claim to be philosophical, with the exception of De aeternitate mundi, the authorship of which is debated, Probus, De prouidentia, and Alexander. Philo embodies un much larger problem: how do we study all these ancient texts in which philosophy is mingled with something else, be it literature or religion

Jules Vuillemin, le pyrrhonisme et Carnéade

Dans cet article j’examine la situation de la Nouvelle Académie dans la classification du scepticisme élaborée par Jules Vuillemin. Celui-ci, dans une étude intitulée « Une morale est-elle compatible avec le scepticisme ? », a distingué quatre types de scepticisme : le scepticisme radical, celui de Pyrrhon ; le scepticisme esthète ou raffiné, celui d’Aristippe ; le probabilisme individuel, celui de Carnéade ; et le probabilisme démocratique, celui de Hume. Or cette classification présente de multiples difficultés. Est-il légitime de faire usage à propos de la Nouvelle Académie du concept de « scepticisme » qui la définit beaucoup plus par rapport au néopyrrhonisme d’Enésidème et de Sextus Empiricus que par rapport à ses racines platoniciennes ? Comment ignorer le fait que les arguments de Carnéade n’étaient pas formulés propria persona, mais dans un processus dialectique anti-stoïcien ? Et que dire de tous les textes qui, notamment sur la question du plaisir, ne correspondent pas à son analyse ? Et pour terminer, le fait que Villemin cite pour l’essentiel le témoignage cicéronien, pose le problème des différences sémantiques entre le latin et le grec.The purpose of this article is to analyze the place of the New Academy in the classification of Scepticism elaborated by Jules Vuillemin. In his 1985 paper “Une morale est-elle compatible avec le scepticisme?”, Vuillemin distinguished four types of Scepticism: the radical kind embodied by Pyrrho; the aesthetic or sophisticated kind represented by Aristippus; the individual probabilism of Carneades; and the democratic probabilism incarnated by Hume. This classification raises several difficulties. Is it legitimate to apply the concept of Scepticism to the New Academy which did not exist at the time of Carneades? By using this concept, Vuillemin characterizes the New Academy by referring to the neo-Scepticism of Enesidemus and Sextus Empiricus rather than to the Platonic roots of the New Acedemy. How can it be ignored that the Carneadian arguments were not asserted propria persona but instead in the framework of a dialectic anti-Stoic process? What about all the texts which do not correspond to Vuillemin’s analysis—especially those on the problem of the pleasure? Last, but not least, the fact that Vuillemin works almost exclusively on Ciceronian passages raises the problem of the semantic differences between Greek and Latin

Exact Random Walk Distributions using Noncommutative Geometry

Using the results obtained by the non commutative geometry techniques applied to the Harper equation, we derive the areas distribution of random walks of length $N$ on a two-dimensional square lattice for large $N$, taking into account finite size contributions.Comment: Latex, 3 pages, 1 figure, to be published in J. Phys. A : Math. Ge

Modelling the effect of the tidal cycle on the high phytoplankton biomass area of Cape Trafalgar (SW Iberian Peninsula)

Physical–biological interactions in the ocean are known to be crucial for understanding ecosystem processes. In this study, we examine the influence of the tide-topography interaction on the high productivity area of Cape Trafalgar using a high-resolution ocean circulation model coupled to an ecosystem model. The obtained results highlight the relevance of the tidal cycle explaining the high phytoplankton biomass that characterises this region through an active and periodic forcing, resulting in a pulsating upwelling system. Our model shows that the interaction of the westward zonal component of the tidal current (uvel) with the submarine ridge that characterises this region, which is perpendicular to the coast, results in the pumping of deep, cold, salty, and nutrient-rich waters to the well-illuminated subsurface waters, fuelling phytoplankton growth. At the same time, the interaction of the westward tidal current with the ridge leads to the development of a cyclonic eddy, which enables the redistribution of the upwelled waters over and to the east of Barbate High. The fortnightly tidal period has been identified as the most influential because (an effective) tidal-pumping process only takes place when the westward uvel is ∼ 0.42 m s−1, a condition attained between ∼ 3 days before and after the moment of maximum tidal flow during spring tides. Simultaneously, the energy and the associated horizontal and vertical mixing of the cyclonic gyre also vary with the tidal cycle, being stronger during spring tides. Both tidally driven processes, i.e., the cyclical upslope advection of deep nutrient-rich water and the influence of the cyclonic gyre, are the main mechanisms that lead to the development of a persistent phytoplankton-rich tongue over Barbate High. Consequently, Cape Trafalgar acts as a source of nutrient- and phytoplankton-rich waters to the surrounding waters

The Lagrange and Markov spectra from the dynamical point of view

This text grew out of my lecture notes for a 4-hours minicourse delivered on October 17 \& 19, 2016 during the research school "Applications of Ergodic Theory in Number Theory" -- an activity related to the Jean-Molet Chair project of Mariusz Lema\'nczyk and S\'ebastien Ferenczi -- realized at CIRM, Marseille, France. The subject of this text is the same of my minicourse, namely, the structure of the so-called Lagrange and Markov spectra (with an special emphasis on a recent theorem of C. G. Moreira).Comment: 27 pages, 6 figures. Survey articl

Insights from quantitative and mathematical modelling on the proposed WHO 2030 goals for Chagas disease

article publié sur la plateforme Gates Open researchChagas disease (CD) persists as one of the neglected tropical diseases (NTDs) with a particularly large impact in the Americas. The World Health Organization (WHO) recently proposed goals for CD elimination as a public health problem to be reached by 2030 by means of achieving intradomiciliary transmission interruption (IDTI), blood transfusion and transplant transmission interruption, diagnostic and treatment scaling-up and prevention and control of congenital transmission. The NTD Modelling Consortium has developed mathematical models to study Trypanosoma transmission dynamics and the potential impact of control measures. cruzi Modelling insights have shown that IDTI is feasible in areas with sustained vector control programmes and no presence of native triatomine vector populations. However, IDTI in areas with native vectors it is not feasible in a sustainable manner. Combining vector control with trypanocidal treatment can reduce the timeframes necessary to reach operational thresholds for IDTI (<2% seroprevalence in children aged <5 years), but the most informative age groups for serological monitoring are yet to be identified. Measuring progress towards the 2030 goals will require availability of vector surveillance and seroprevalence data at a fine scale, and a more active surveillance system, as well as a better understanding of the risks of vector re-colonization and disease resurgence after vector control cessation. Also, achieving scaling-up in terms of access to treatment to the expected levels (75%) will require a substantial increase in screening asymptomatic populations, which is anticipated to become very costly as CD prevalence decreases. Further modelling work includes refining and extending mathematical models (including transmission dynamics and statistical frameworks) to predict transmission at a sub-national scale, and developing quantitative tools to inform IDTI certification, post-certification and re-certification protocols. Potential perverse incentives associated with operational thresholds are discussed. These modelling insights aim to inform discussions on the goals and treatment guidelines for CD

Dimensional Transmutation and Dimensional Regularization in Quantum Mechanics. II: Rotational Invariance

A thorough analysis is presented of the class of central fields of force that exhibit: (i) dimensional transmutation and (ii) rotational invariance. Using dimensional regularization, the two-dimensional delta-function potential and the $D$-dimensional inverse square potential are studied. In particular, the following features are analyzed: the existence of a critical coupling, the boundary condition at the origin, the relationship between the bound-state and scattering sectors, and the similarities displayed by both potentials. It is found that, for rotationally symmetric scale-invariant potentials, there is a strong-coupling regime, for which quantum-mechanical breaking of symmetry takes place, with the appearance of a unique bound state as well as of a logarithmic energy dependence of the scattering with respect to the energy.Comment: 29 pages. To appear in Annals of Physic

Extensional and Intensional Strategies

This paper is a contribution to the theoretical foundations of strategies. We first present a general definition of abstract strategies which is extensional in the sense that a strategy is defined explicitly as a set of derivations of an abstract reduction system. We then move to a more intensional definition supporting the abstract view but more operational in the sense that it describes a means for determining such a set. We characterize the class of extensional strategies that can be defined intensionally. We also give some hints towards a logical characterization of intensional strategies and propose a few challenging perspectives

Modelling the effect of the tidal cycle on the high phytoplankton biomass area of Cape Trafalgar (SW Iberian Peninsula)

Physical-biological interactions in the ocean are known to be crucial for understanding ecosystem processes. This is particularly relevant in the highly dynamic coastal regions, where the biogeochemical processes associated with higher-frequency perturbations such as tidal waves play a key role in primary production. In this study, we examine the influence of the tide-topography interaction on the high productivity area of Cape Trafalgar (NW limit of the Strait of Gibraltar, Iberian Peninsula) using a high-resolution ocean circulation model coupled to an ecosystem model. The obtained results highlight the relevance of the tidal cycle explaining the high phytoplankton biomass that characterises this region through an active and periodic forcing, resulting in a pulsating upwelling system. Our model shows that the interaction of the westward zonal component of the tidal current (uvel) with the submarine ridge (i.e., Barbate High) that characterises this region, which is perpendicular to the coast, results in the pumping of deep, cold, salty, and nutrient-rich waters to the well-illuminated subsurface waters, fuelling phytoplankton growth. At the same time, the interaction of the westward tidal current with the ridge leads to the development of a cyclonic eddy, which enables the redistribution of the upwelled waters over and to the east of Barbate High. The fortnightly tidal period has been identified as the most influential because (an effective) tidal-pumping process only takes place when the westward uvel is ∼0.42 m s−1, a condition attained between ∼3 days before and after the moment of maximum tidal flow during spring tides. Simultaneously, the energy and the associated horizontal and vertical mixing of the cyclonic gyre also vary with the tidal cycle, being stronger during spring tides. Both tidally driven processes, i.e., the cyclical upslope advection of deep nutrient-rich water and the influence of the cyclonic gyre, are the main mechanisms that lead to the development of a persistent phytoplankton-rich tongue over Barbate High. Consequently, Cape Trafalgar acts as a source of nutrient- and phytoplankton-rich waters to the surrounding waters