Monday, October 29, 2007

Francesco Berto

Lundi 29 octobre, à 17h30 dans la grande salle de l'IHPST, le séminaire Philmath reçoit Francesco Berto (IHPST-CNRS-ENS):

Some of the strangest outcomes of paraconsistency have to do with inconsistent arithmetic and impossible numbers. Traditional-minded logicians usually get puzzled when one mentions the astonishing applications of paraconsistency in formal arithmetic. However, at the cost of some incredulous stares (which usually begin when one mentions the fact that paraconsistent arithmetics include contradictory numbers, and especially numbers which are identical to their immediate successor), one gets a world in which even well-established limitative results of ordinary metamathematics, such as Gödel’s Theorems, begin to fluctuate. In this talk I summarize some of the main results around, which are as unfamiliar to the general audience as they are innovative and interesting. The presentation is focused on *relevant* arithmetics, i.e., on formal systems for arithmetic whose underlying logic is some relevantlogic. After giving bits of relevant proof theory, I switch to a model-theoretic approach (which I find philosophically much more stimulating). I introduce a useful *collapsing filter*, which turns the so-called standard model of arithmetic into interesting inconsistent models by shrinking in an appropriate way its cardinality.

Friday, October 19, 2007

V. Hendricks

Philform reçoit Vincent Hendricks (Roskilde University, Denmark) le lundi 22 octobre de 14h à 16h dans la grande salle de l'IHPST.

Limiting Skepticism

Abstract/ Modal operator epistemology is a formal epistemological paradigm obtained by mixng modal, tense and epistemic logic with rudimentary elements from formal learning theory. The paradigm was developed in The Convergence of Scientific Knowledge (Springer: 2001) and used there and elsewhere to study the validity of limiting convergent knowledge(Mainstream and Formal Epistemology (Cambridge UniversityPress, 2006)).Studying knowledge is also studying skepticism. Skepticism is usually considered to being a short-run strategy. Using modal operator epistemology this paper scrutinizes what happens to skepticism in the long run: Can skepticism outstrip knowledge in the limit?

Tuesday, October 16, 2007

Wednesday, October 10, 2007

Atelier sur la causalité à l'IHPST

IHPST, lundi 15 octobre 2007, Grande Salle
Organisé par Mikaël Cozic (IHPST/GREGHEC) et Philippe Mongin (GREGHEC/IHPST)

Programme :
14h30-15h30 : D. Hausman (University of Wisconsin, Madison), “Explaining by Citing Causes ”
15h30-16h30 : I. Drouet (IHPST), “Utiliser les réseaux bayésiens pour inférer des causes”
16h30-17h30 : Ph. Huneman (IHPST), titre à venir

Tuesday, October 09, 2007

Fundamenta Mathematicae

Archives of the famous journal Fundamenta Mathematicae are available online free.

[via LogBlog]

Joe Salerno

Joe Salerno has given a talk at Philform seminar yesterday, on "Counterpossible Conditionals"

ABSTRACT: Subjunctive conditionals with impossible antecedents (or counterpossibles) are standardly treated as vacuously true---the classical lore being that if an impossibility were to obtain, then anything would be the case. We'll discuss and develop a non-vacuous reading for (some) counterpossibles. The account provides resources for capturing some illusive philosophical notions---including the intuitive difference between essence and necessity, and an intuitive account of epistemic possibility.