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Lectures 200708  
Unless otherwise specified, the lectures are held on Saturday mornings, 11 am.
Please note that Rini's lecture is exceptionally scheduled on Tuesday 20 May, 14h, as a joint activity with the Centrum
for Logica en Wetenschapsfilosofie (VUB). CANCELED (because of a train strike).
Please note also that all BSLPS lectures are now held  unless otherwise specified  at the Auditorium Bordet Écuries royales / Koninklijke Stallingen Palais des Académies / Paleis der Academiën Rue Ducale / Hertogsstraat 1 1000 Bruxelles / Brussel Archives of 200607 lectures are available here. Abstracts
In this talk I will first present calculi of individuals  that is, theories for which it is common that they are considered to be nominalistic  and extensions of them formulated in wider vocabularies: e.g., in a vocabulary which contains topological or geometrical notions. I then address the topic of the prooftheoretic strength of these theories: how much mathematics can be developed in them, and how do they relate to each other? Finally, I want to touch the question whether they still deserve to be classified as nominalistically acceptable theories. Dans les théories physiques conventionnelles, celles qui sont
opératoires aujourd'hui (mécanique classique, physique quantique,
relativités restreinte et générale), le principe de causalité, en
imposant un ordre entre certains événements, contraint de l'extérieur
la façon de représenter le temps. Mais certaines "nouvelles physiques"
qui sont à l'ébauche aujourd'hui visent à renverser cette logique en
partant de l'idée que la causalité est une donnée première et en
tentant de montrer que le temps lisse et continu que nous connaissons
est une propriété qui émerge, à une certaine échelle, à partir d'un
inframonde dans lequel il n'y a pas de temps prédéfini mais dans lequel
se trouvent déjà des événements causalement reliés. Le temps ne serait
alors qu'une émanation de la causalité. Nous tenterons de présenter et
d'analyser ces différentes démarches.
I will argue, with reference to various central areas of
mathematics, that the Gödel Incompleteness Phenomenon remains very
remote from the concerns of mathematicians. I will sketch some arguments
that PA (First Order Peano Arithnmetic), far from being a weak system,
is extremely strong, and well able to accommodate such sophisticated
arguments as those going into the Wiles proof of Fermat's Last Theorem.
The basic ideas, both philosophical and mathematical, go back to work of
Kreisel in the 1950's.
In the literature on the foundations of the special theory of
relativity, Malament's theorem on the conventionality of simultaneity
has often been taken to settle the issue in a definitive way. Recently,
there has been some discussion about some of its premises, but the
issue of what it means to claim that simultaneity is conventional has
not been addressed and reevaluated. In the talk I will try to show that two issues that in the literature
have been so far regarded as independent of each other are connected in
the following way: if there is objective relativistic becoming, then
simultaneity is conventional.
Evidence for
causal claims comes in a variety of forms in the social sciences. The
most important of these are evidence of what would have been, evidence
of regularities, evidence of certain statistical relations,evidence of
connecting mechanisms and evidence of invariant relationships. Social
scientists often use evidence from more than one source in order to
confirm a single causal hypothesis and sometimes even demand a
plurality of evidence in order for a causal hypothesis to be regarded
as established. The overall aim of this paper is to provide an analysis
of this state of affairs and draw some methodological conclusions. A
number of philosophers have recently offered pluralistic perspectives
on causation. Here I distinguish epistemic, conceptual and metaphysical
versions of pluralism and consider some of the arguments in favour of
these. Ignoring metaphysical issues here, I end up with a form of
evidential monism but conceptual pluralism about causation in the
social sciences.
This
paper concerns Gödel’s conception of the reality of
mathematical objects. I distinguish three claims (i), (ii), (iii).
(i) “Mathematics describes a nonsensual reality, which exists independently both of the acts and [of] the dispositions of the human mind.” (ii) “Mathematical objects and facts (or at least something in them) exist objectively and independently of our mental acts and decisions.” (iii) Mathematics (or something in mathematics) is independent of the specific properties of the human being. Claim (i) is usually quoted to characterize Gödel’s Platonism. However, relying on the unpublished papers (in particular Gödel’s drafts), I argue that Gödel cannot hold such a strong Platonism after 1954. His position is better described by the two weaker claims, (ii) and (iii). Claims (ii) and (iii) offer two different meanings for the idea of an 'objectivity' of mathematics. I discuss, using as much as possible Gödel’s interpretation of their writings, the position of other mathematicians (Brouwer, Dedekind), or philosophers (Husserl, Lautman), with regard to the three claims (i), (ii) and (iii). Philosophers of time frequently talk about a tenseless 'is'  for example
Tooley's "There are (tenselessly) dinosaurs." A tenseless sentence is
supposed not to change its truth value with the passage of time. It's
supposed to have its truth value absolutely. But of course we need a
semantic analysis of that. This papers looks at what might be involved in
such an analysis by looking at the parallel modal case  i.e., by looking at
what would be involved in a noncontingent 'is'. I will pay particular
attention to the need for tenseless or noncontingent sentences to be
incorporated into constructions in tensed and contingent languages with a
compositional semantics.
