Dear all,

We will have a joint NiHil and LIRa session tomorrow, on Thursday, 1 February 15:10, Room F0.01, Bushuis in Kloveniersburgwal 48. NOTE the unusual time and location.

This will be a hybrid session. If you want to attend online, please use NiHiL seminar Zoom link: https://uva-live.zoom.us/s/87618965843 NOTE: this is NOT a usual LIRa Zoom link, as it was stated in the previous mail. Sorry for the confusion.

You can find the details of the talk below.

This will be a joint session together with the NihiL seminar, as a part of NiHiL workshop.

Speaker: Hannes Leitgeb (Münich)

Title: The Logic of Theoretical Reasons. An Axiomatic Account

Date and Time: Thursday, 1 February, 15:10-16:10

Venue: Room F0.01, Bushuis in Kloveniersburgwal 48 or virtually via Zoom at https://uva-live.zoom.us/s/87618965843.

Abstract: the talk argues for a system of axioms and definitions that is meant to capture the logic of theoretical reasons, that is, of reasons for belief. The system concerns a primitive direct-reason-for relation, a defined inferential-reason-for relation, an identity criterion for reasons, a primitive aggregation function for reasons, and a primitive function for the revision of belief by reasons. Reasons are assumed to speak for propositions with numerical strengths, the aggregation of reasons involves intersections of propositions and sums of strengths, belief is reconstructed as subjective probability, and ratios of new-to-old-odds are postulated to be a function of strengths of reason. The resulting theory avoids problems that have been ascribed to the additive aggregation of reasons, it entails that reasons conform to a vector structure and that the impact of a reason on belief corresponds to a probabilistic Jeffrey-Field-update, and although the theory differs from existing logics of reason, it is partially continuous with two of them.

Hope to see you there!

The LIRa team