We give a geometric realization of space-time spinors and associated representations, using the Jordan triple structure associated with the Cartan factors of type 4, the so-called spin factors. We construct certain representations of the Lorentz group, which at the same time realize bosonic spin-1 and fermionic spin- $${\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern-0em}\!\lower0.7ex\hbox{$2$}}$$ wave equations of relativistic field theory, showing some unexpected relations between various low-dimensional Lorentz representations. We include a geometrically and physically motivated introduction to Jordan triples and spin factors.

The classics appear conspicuously in the pamphlet wars of the American Revolution, though in the opinion of Bernard Bailyn , their presence is “window-dressing” and their influence “superficial.” They are “ everywhere illustrative, not determinative, of thought” . Up the scale in influence comes Enlightenment rationalism, also “superficial” but only “at times”—that removes the foreigners, ancient and modern. Then, further up the scale are English common-law writers, “powerfully influential” though still insufficiently “determinative”; above them, a “major source,” New England (...) Puritan thought and culture; and finally, at the top, seventeenth-century British “heroes of liberty” and the “early eighteenth-century transmitters of this tradition,” e.g. Commonwealth men, Bishop Hoadly. Who would have thought that the bishop of Winchester weighed in the balance more heavily than Plato and Aristotle? Only once in passing does Bailyn even mention Machiavelli, to whom J. G. A. Pocock, Quentin Skinner, and Harvey C. Mansfield would grant large prominence in the development of Revolutionary thought. (shrink)

The emphasis placed by H. Atlan, like G. Bateson, on the reception of messages during communication between subsystems leads to a conception of learning, and more generally of human memory, surprisingly close to that proposed by I. Rosenfield on the basis of the work of G. M. Edelman. The authors stressed the close and reciprocal link between the theory of functional localization and the conception of memory, which they have just seen, radically refuted by Rosenfield. The theory of functional localization (...) therefore considers as established the existence of a whole series of rigid relationships between specific locations in the brain and certain major functions performed by the body. Thus briefly summarized, the theory of neural Darwinism provides positive evidence in favor of the Rosenfield's theory of human memory. All these characteristics make the functioning of human memory an outstanding example of the natural complexity of a self‐organized system in the sense of Atlan. (shrink)

Whatever our profession we are all engulfed in daily life and in the obscurity and density of the mental world. Who is this “I” that finds expression in such a wide variety of societies, in the convictions of the group and temperament of the individual self, in all that I perceive imperfectly and that makes me me? What does this sometimes slippery, sometimes thorny “I” say about the various attitudes towards knowing: the things I desperately want to know, things I (...) believe myself capable of dispensing with, those I fear knowing? (shrink)

Le polythéisme polynésien était-il une forme métaphorique de panthéisme ?

Cet article défend l’idée de l’existence d’une analyse originale de Lemercier de la Rivière quant au concept de despotisme légal non révélée par les commentateurs. Quesnay, chef de file des physiocrates est habituellement reconnu pour son initiative en la matière mais la littérature mobilise systématiquement les écrits de Lemercier de la Rivière pour en faire l’exposé complet. La même ambiguïté apparaît quant à l’écriture du principal texte de Lemercier de la Rivière : L’Ordre naturel et essentiel des sociétés politiques. Cet (...) article apporte un éclairage nouveau sur les projets physiocratiques pour fonder un état de droit. (shrink)

Suite aux attaques diverses qui en annoncent la fin imminente, faut-il renvoyer l'humanisme aux oubliettes de l'histoire? Cet idéal d'homme complet dont le développement physique, affectif, intellectuel et moral ne souffre pas de limites, qui substitue à l'esprit de soumission celui de libre examen, est-il désormais dépassé? La personne, le sujet, la liberté, le progrès, ne sont-ils que des chimères inconsistantes? La raison n'est-elle qu'un instrument trompeur? Faut-il abandonner les hommes au fatalisme le plus radical? L'humanisme semble désormais faire l'objet (...) de critiques sévères. Est-il pour autant dépassé? (shrink)