Au Congrès de philosophie scientifique de 1935 comme lors du lancement de l’Encyclopédie internationale de la science unifiée, Federigo Enriques était reconnu par les néo-positivistes comme un de leurs pères fondateurs, sans qu’il fût tout à fait d’accord. À Paris, Enriques représentait le groupe des philosophes des sciences italiens et son nom était lié au journal Scientia, ouvert aux contributions des positivistes logiques. Ces derniers, désireux de constituer un front commun pour lutter contre les philosophies idéalistes et métaphysiques alors dominantes, (...) surestimaient sans doute la force du groupe italien, comme ils sous-estimaient les critiques d’Enriques sur l’usage de la logique formelle ou sur l’importance du langage. Dès les débuts de son implication en philosophie, il avait souligné la nécessité d’une fondation psychologique des concepts scientifiques, et en 1901, il avait donné un exemple de ce type d’analyse pour les postulats de la géométrie. Il n’appréciait guère les travaux logiques de Giuseppe Peano, affirmant que son formalisme manquait de bases psychologiques. Cependant, contre les mouvements anti-rationalistes de son temps, il défendait la valeur cognitive de la science et, dans ce climat d’appréciation mutuelle, les différences passaient au second plan. (shrink)

In the Tractatus, it is stated that questions about logical formatting cannot be meaningfully formulated, since it is precisely the application of logical rules which enables the formulation of a question whatsoever; analogously, Wittgenstein’s celebrated infinite regress argument on rule-following seems to undermine any explanation of deduction, as relying on a logical argument. On the other hand, some recent mathematical developments of the Curry-Howard bridge between proof theory and type theory address the issue of describing the “subjective” side of logic, (...) that is, the concrete manipulation of rules and proofs in space and time. It is advocated that such developments can shed some light on the question of logical formatting and its apparently unintelligible paradoxes, thus reconsidering Wittgenstein’s verdict. (shrink)

whole numbers that manages to assert that it itself is unprovable (from a given finite set F of axioms using formal logic). (Gödel's paper is included in the well-known anthology [1].) GF : ``GF cannot be proved from the finite set of axioms F.'' This assertion GF is therefore true if and only if it is unprovable, and the formal axiomatic system F in question either proves falsehoods (because it enables us to prove GF) or fails to prove a true (...) assertion (because it does not enable us to prove GF). If we assume that the former situation is impossible, we conclude that F is necessarily incomplete since it does not permit us to establish the true statement GF. (shrink)

In a review of Russell’s Principles from 1904, Edwin B. Wilson pays great attention to Peano’s work and that of his collaborators. His purpose was to make this work known in the USA where it “unfortunately is very little known and still less appreciated”. Wilson expands Russell’s well-known acknowledgement of Peano’s influence on his own development, seeing in Peano’s logic more than a new “mathematical tool”, describing Peano as a kind of proto-logicist, and defending him from Poincaré’s criticisms. Especially in (...) geometry, he vindicates several priority issues for Peano’s school with respect to Hilbert in the philosophy of the axiomatic method. (shrink)

In a review of Russell’s Principles from 1904, Edwin B. Wilson pays great attention to Peano’s work and that of his collaborators. His purpose was to make this work known in the USA where it “unfortunately is very little known and still less appreciated”. Wilson expands Russell’s well-known acknowledgement of Peano’s influence on his own development, seeing in Peano’s logic more than a new “mathematical tool”, describing Peano as a kind of proto-logicist, and defending him from Poincaré’s criticisms. Especially in (...) geometry, he vindicates several priority issues for Peano’s school with respect to Hilbert in the philosophy of the axiomatic method. (shrink)

This book introduces readers to the narrative structure of mathematical proofs and why mathematicians communicate that way, drawing examples from classic literature and employing metaphors and imagery.

In his book Gabriele Lolli discusses the notion of proof, which is, according to him, the most important and at the same time the least studied aspect of mathematics. According to Lolli, a theorem is a conditional sentence of the form ‘if T then A’ such that A is a logical consequence of T, where A is a sentence and T is a sentence or a conjunction or set of sentences. Verifying that A is a consequence of T generally involves (...) considering infinitely many interpretations; so it is something which is impossible to do in finite terms. Proofs may serve as ‘shortcuts’ in this respect. A proof is defined by Lolli as any finite argument certifying that A is a consequence of T. A proof is a shortcut in the sense that it spares us considering infinitely many interpretations.The reason for such a very general definition of proof is Lolli's strong belief that mathematics is not a rigid system of explicit rules, but rather a set of tools; as a consequence, there is no prescription as to what a proof should or should not be. Actually, mathematics is historically situated and not timeless, and the history of mathematics is the …. (shrink)