Korbinian Friedl M.Sc. M.A.

June 01st until August 31st, 2025

Affiliation: London School of Economics and Political Science

Research for a study about:

Verifiability, Probability and Thick Ethical Concepts

Hannes Leitgeb's recent paper "Vindicating the Verifiability Criterion" presents a new attempt at drawing out the exact sense in which (something like) verifiability is properly seen as the arbiter of meaningfulness. He proposes a parametrized, probabilistic verifiability criterion "scheme".

This project interrogates Leitgeb's approach from two directions:

First: Leitgeb advertises as one of the advantages of his criterion its greater flexibility compared to the original version. He discusses, for example, how even metaphysical schools---paradigmatic targets of verifiability-based charges of meaninglessness---could parametrize his criterion in a way that shows how their statements could be meaningful. One issue with the original criterion I am particularly interested in is Putnam's argument that it implies a non-cognitivism about value-judgments which entrenches a strong dichotomy of fact and value that cannot properly make sense of, among other things, the specific way in which Thick Ethical Concepts are meaningful. This project investigates whether Leitgeb's proposal has the resources to give a satisfying account of judgments involving such terms. 

Second, it investigates how Leitgeb's (probabilistic) criterion interacts with different concepts of probability. The criterion gets its specifically *semantic* purchase via it's link to a Bayesian version of dynamic semantics, and has appeal for pragmatists through its link to Bayesian decision theory. A subjective Bayesian concept of probability would fit in very well with this picture. But tying probability assignment too closely to betting behaviour runs the risk of letting the criterion's new-found flexibility slip through our fingers again; since arguably a bet only makes sense if we have a method for settling it, and settling a bet on p must involve a verification or falsification of p. The second prong of the project, therefore, thinks about what exactly we should have in mind when speaking of "probability" in the context of Leitgeb's probabilistic verifiability criterion.

Lecture

Leitgeb’s new verifiability criterion, probability, and thick concepts

Philosophy of Science Colloquium 

Date: June 26, 2025

Time: 5.30 pm CET

Venue for all talks: Lecture Hall 3A, NIG Universitätsstraße 7, 3rd floor, NIG/ Neues Institutsgebäude, Universitätsstraße 7, 1010 Vienna

Abstract: 

Hannes Leitgeb's recent paper "Vindicating the Verifiability Criterion" presents a new attempt at drawing out the exact sense in which (something like) verifiability is properly seen as the arbiter of meaningfulness. He proposes a parametrized, probabilistic verifiability criterion "scheme". As one of the advantages of his new criterion, compared to the "original" verifiability criterion, he advertises its greater flexibility, and the ability to account for, and make explicit (in terms of different parametrizations), the different ways in which certain statements can be meaningful for different communities.
The talk will present Leitgeb's ideas and raise to questions for them:1. One issue with the original criterion is the strong dichotomy between fact and value it entrenches, which e.g. Putnam argues makes it impossible for it to account for the specific way in which Thick Ethical Concepts are meaningful. Does the greater flexibility of Leitgeb's criterion allow it to give a satisfying account of judgments involving such terms?2. How does Leitgeb's probabilistic criterion interact with different concepts of probability? Are there specific requirements on a concept of probability which are necessary for the criterion to achieve its semantic bite?