Four years after completing his Ph.D. on “The Psychology of Kant,” one of Peirce’s most famous students, John Dewey, published a compendium of Leibniz’s main theses, his 1888 Leibniz’s New Essays.1 Such a move from critical to pre-critical rationalism seems to echo Peirce’s judgment that to fully understand Kant, a thorough familiarity with Leibniz’s philosophy is an indispensable preliminary (N 2:186, 1899); for Kant himself “was reposing in a firm belief in the metaphysics of Leibnitz as theologized by Wolff when (...) he first read the book of Hume.” (W 1:104, 1863) Peirce himself started his reflection with the study of Kant’s thought. The purpose of the present paper is to demonstrate that his actual implicit.. (shrink)

Le philosophe américain Charles S. Peirce ne trouva, malgré ses efforts, guère d’interlocuteurs en France. On le considéra comme un mathématicien et logicien, un physicien et un psychologue fiable, mais son œuvre philosophique fut systématiquement distordue au gré des controverses franco-françaises. Nous mettons l’accent sur les lectures d’André Lalande et de Louis Couturat qui contribuèrent néanmoins à faire reconnaître en France l’originalité du père du pragmaticisme.Despite his efforts, the American philosopher Charles S. Peirce found hardly any interlocutors in France. He (...) was considered mostly as a mathematician and logician, a physicist and a reliable psychologist, but his philosophical work was systematically distorted in consequence of “Franco-French” disputes. We emphasize here the readings of André Lalande and Louis Couturat who made significant contributions towards the recognition in France of the originality of the founding father of Pragmaticism. (shrink)

L’article examine les raisons philosophiques, plutôt que mathématiques ou logiques, pour lesquelles MacColl a pu vouloir développer une logique propositionnelle. Nous trouvons des éléments de réponse dans le refus discret d’endosser une logique des choses, dans l’anti-psychologisme nuancé de MacColl, et dans une subtile épistémologie de la certitude liée à un usage méthodique de la grammaire.

ABSTRACT : Alfred Fouillee's doctrine of ideas-forces approximates historically and intellectually William James’s theory of will. But Fouillee's criticism of pragmatism also has connections with Pierce's emphasis on the real and the analysis of concepts, and shows an influence of tychism approaching mysticism. -/- .

L’article examine les raisons philosophiques, plutôt que mathématiques ou logiques, pour lesquelles MacColl a pu vouloir développer une logique propositionnelle. Nous trouvons des éléments de réponse dans le refus discret d’endosser une logique des choses, dans l’anti-psychologisme nuancé de MacColl, et dans une subtile épistémologie de la certitude liée à un usage méthodique de la grammaire.

A new description of gravitational motion will be proposed. It is part of the proper time formulation of physics as presented on the IARD 2000 conference. According to this formulation the proper time of an object is taken as its fourth coordinate. As a consequence, one obtains a circular space–time diagram where distances are measured with the Euclidean metric. The relativistic factor turns out to be of simple goniometric origin. It further follows that the Lagrangian for gravitational dynamics does not (...) require an interpretation in terms of curvature of space–time. The flat space model for gravitational dynamics leads to the correct predictions for the bending of light, the perihelion shift of Mercury and gravitational red-shift. The new theory is free of singularities. More important, the new formulation of gravitational dynamics restores the validity of the principle of addition of potentials. One therefore can find solutions for static gravitational configurations for which it is difficult to find the solution of the corresponding Einstein equations. The method will be illustrated by means of the orbital precession for non-spherical stellar mass distributions. In case of the bipole mass distribution the agreement with the predictions of the general theory of relativity is very striking. Nevertheless, the new model is far more simple. (shrink)

It will be argued that Minkowski's implementation of distances is inconsistent. An alternative implementation will be proposed. In the new model the proper time of an object is taken as its fourth coordinate. Distances will be measured according to a four dimensional Euclidean metric. In the present approach mass is a constant of motion. A mass can therefore be ascribed to photons and neutrinos. Mechanics and dynamics will be reformulated in close correspondence with classical physics. Of particular interest is the (...) equation of motion for the proper time momentum. In the classical limit it reduces to the classical law of conservation of (kinetic+potential) energy. In the relativistic limit it is similar to the conservation of energy of the theory of relativity. The conservation of proper time momentum allows for an alternative explanation for Compton scattering and pair annihilation. On the basis of the proper time formulation of electrodynamics also an alternative explanation will be offered for the spectra of hydrogenic atoms. The proper time formulation of gravitational dynamics leads to the correct predictions of gravitational time dilation, the deflection of light and the precession of the perihelia of planets. For this no curvature will be needed. That is, spacetime is flat everywhere, even in the presence of sources of gravitation. Some cosmological consequences will be discussed. The present approach gives a new notion to energy, antiparticles and the structure of spacetime. The contents of the present paper will have important implications for the foundations of physics in general. (shrink)

The number of discriminable colours is often assumed to be of the order of several million but the extent of detectable chromatic diversity present in individual natural scenes is an open question. Here, the aim was to estimate the number of discriminable colours seen in natural scenes. Hyperspectral data were obtained from a set of natural scenes over the range 400 - 720 nm at 10 nm intervals (Nascimento et al, 2002 Journal of the Optical Society of America A 19 (...) 1484 - 1490) and the representation of each scene in CIELAB space computed for all pixels of the image. The number of discriminable colours was estimated by counting the number of unit volumes in the three-dimensional volume defined by the scene when represented in CIELAB space. We found that the number of discriminable colours estimated in a scene could vary by an order of magnitude from scene to scene, but rarely exceeded 105, indicating a limited chromatic diversity. (shrink)