The theme « Truth and Certainty » is reminiscent of Hegel’s dialectic of prominent in the Phänomenologie des Geistes, but I want to treat it from a different angle in the perspective of the constructivist stance in the foundations of logic and mathematics. Although constructivism stands in opposition to mathematical realism, it is not to be considered as an idealist alternative in the philosophy of mathematics. It is true that Brouwer’s intuitionism, as a variety of constructivism, (...) has idealistic overtones, but my main concern in this paper is located in the mathematical tradition of constructive mathematics from the Greeks to Fermat, Gauss and Kronecker, and from the logical side, in the finitist doctrine of Hilbert and his followers. (shrink)
Le terme de moment est omniprésent dans l’œuvre de Hegel et les commentateurs n’ont pas suffisamment insisté sur le sens dynamique du « Moment » hégélien qui n’a rien de temporel, mais dénote plutôt le momentum ou moment cinétique de la mécanique newtonienne. Hegel a donné vie à ce concept de moment et en a fait le moteur de sa dialectique qu’on interprète ici comme une syllogistique dynamique de la sursomption des moments du procès de la conscience et du devenir (...) de l’esprit. Une logique dynamique pourrait récupérer avantageusement cette dialectique des concepts. Mais la lecture critique de Hegel veut montrer comment un concept physique est transformé en notion métaphysique et comment une science de la logique « Wissenschaft der Logik » est dévoyée dans une ontologie où c’est une philosophie de la nature qui devient mécanique en assujettissant la physique à un idéalisme objectif supraphysique. Un épilogue sur le vocabulaire hégélien termine l’article. (shrink)
This paper aims at a logico-mathematical analysis of the concept of chaos from the point of view of a constructivist philosophy of physics. The idea of an internal logic of chaos theory is meant as an alternative to a realist conception of chaos. A brief historical overview of the theory of dynamical systems is provided in order to situate the philosophical problem in the context of probability theory. A finitary probabilistic account of chaos amounts to the theory of measurement in (...) the line of a quantum-theoretical foundational perspective and the paper concludes on the non-classical internal logic of chaos theory. Finally, deterministic chaos points to a philosophy which asserts that chaotic systems are no less measurable than other physical systems where predictable and non–predictable phenomena intermingle in a constructive theory of measurement. (shrink)
Hermann Weyl as a founding father of field theory in relativistic physics and quantum theory always stressed the internal logic of mathematical and physical theories. In line with his stance in the foundations of mathematics, Weyl advocated a constructivist approach in physics and geometry. An attempt is made here to present a unified picture of Weyl's conception of space-time theories from Riemann to Minkowski. The emphasis is on the mathematical foundations of physics and the foundational significance of a constructivist philosophical (...) point of view. I conclude with some remarks on Weyl's broader philosophical views. (shrink)
Hilbert's programme is shown to have been inspired in part by what we can call Kronecker's programme in the foundations of an arithmetic theory of algebraic quantities.While finitism stays within the bounds of intuitive finite arithmetic, metamathematics goes beyond in the hope of recovering classical logic. The leap into the transfinite proved to be hazardous, not only from the perspective of Gödel's results, but also from a Kroneckerian point of view.
