Formal Philosophy

Logic at Columbia University

Wheeler: The Rise and Fall of Accuracy-first Epistemology

by Yang Liu

The Rise and Fall of Accuracy-first Epistemology
Gregory Wheeler (Ludwig Maximilian University of Munich)
4:10 pm, October 31, 2014
Room 2, Faculty House, Columbia University

Abstract.  Accuracy-first epistemology aims to supply non-pragmatic justifications for a variety of epistemic norms. The contemporary basis for accuracy-first epistemology is Jim Joyce’s program to reinterpret de Finetti’s scoring-rule arguments in terms of a “purely epistemic” notion of “gradational accuracy.” On Joyce’s account, scoring rules are taken to measure the accuracy of an agent’s belief state with respect to the true state of the world, where accuracy is conceived to be a pure epistemic good. Joyce’s non-pragmatic vindication of probabilism, then, is an argument to the effect that a measure of gradational accuracy satisfies conditions that are close enough to those necessary to run a de Finetti style coherence argument. A number of philosophers, including Hannes Leitgeb and Richard Pettigrew, have embraced Joyce’s program whole hog. Leitgeb and Pettigrew, for instance, have argued that Joyce’s program is too lax, and they have proposed conditions that narrow down the class of admissible gradational accuracy functions, while Pettigrew and his collaborators have sought to extend the list of epistemic norms receiving an accuracy-first treatment, a program that he calls Epistemic Decision Theory.

In this talk I report on joint work with Conor Mayo-Wilson that challenges the core doctrine of Epistemic Decision Theory, namely the proposal to supply a purely non-pragmatic justification for anything resembling the Von Neumann and Morgenstern axioms for a numerical epistemic utility function. Indeed, we argue that none of the axioms necessary for Epistemic Decision Theory have a satisfactory non-pragmatic justification, and we point to reasons why to suspect that not all the axioms could be given a satisfactory non-pragmatic justification. Our argument, if sound, has consequences for recent discussions of “pragmatic encroachment”, too. For if pragmatic encroachment is a debate to do with whether there is a pragmatic component to the justification condition of knowledge, our arguments may be viewed to address the true belief condition of (fallibilist) accounts of knowledge.

Workshop on Pragmatics, Relevance and Game Theory

by Yang Liu

Workshop on Pragmatics, Relevance and Game Theory
CUNY Graduate Center, Rm. 9207
October 14 and 15, 2014

Preliminary list of speakers:
Deirdre Wilson (UCL)
Laurence Horn (Yale)
Kent Bach (SFSU)
Robyn Carston (UCL)
Ariel Rubinstein (NYU and Tel Aviv)

Michael Devitt
Stephen Neale
Rohit Parikh

Marilynn Johnson (CUNY)
Ignacio Ojea (Columbia)
Todd Stambaugh (CUNY)
Cagil Tasdemir (CUNY)

Program here.

Ramanujam: Reasoning in games that change during play

by Yang Liu

Reasoning in games that change during play
R. Ramanujam (Institute of Mathematical Sciences, India)
4:00 – 6:00 PM, Friday, June 2, 2014
Room 4421, CUNY GC

Abstract. We consider large games, in which the number of players is so large that outcomes are determined not by strategy profiles, but by distributions. In the model we study, a society player monitors choice distributions and intervenes periodically, leading to game changes. Rationality of individual players and that of the society player are mutually interdependent in such games. We discuss stability issues, and mention applications to infrastructure problems.

Pacuit: Knowledge-Theoretic Aspects of Strategic Voting

by Yang Liu

Knowledge-Theoretic Aspects of Strategic Voting
Eric Pacuit (University of Maryland)
4:15 – 6:15 PM, Friday, May 9, 2014
Room 3309, CUNY GC

Abstract. It has long been noted that a voter can sometimes achieve a preferred election outcome by misrepresenting his or her actual preferences. In fact, the classic Gibbard-Sattherthwaite Theorem shows that under very mild conditions, every voting method that is not a dictatorship is susceptible to manipulation by a single voter. One standard response to this important theorem is to note that a voter must possess information about the other voters’ preferences in order for the voter to decide to vote strategically. This seems to limit the “applicability” of the theorem. In this talk, I will survey some recent literature that aims at making this observation precise. This includes models of voting under uncertainty (about other voters’ preferences) and models that take into account how voters may response to poll information.

Leitgeb: The Humean Thesis on Belief

by Yang Liu

The Humean Thesis on Belief
Hannes Leitgeb (Ludwig Maximilian University of Munich)
4:15 pm, May 2nd, 2014
716 Philosophy Hall, Columbia University

Abstract.  I am going to make precise, and assess, the following thesis on (all-or-nothing) belief and degrees of belief: It is rational to believe a proposition just in case it is rational to have a stably high degree of belief in it.I will start with some historical remarks, which are going to motivate calling this postulate the “Humean thesis on belief”. Once the thesis has been formulated in formal terms, it is possible to derive conclusions from it. Three of its consequences I will highlight in particular: doxastic logic; an instance of what is sometimes called the Lockean thesis on belief; and a simple qualitative decision theory.

Egan: Three Grades of Self-Involvement

by Ignacio Ojea

Three Grades of Self-Involvement
Andy Egan (Rutgers University)
4:10-6:00 PM, April 3rd, 2014
716 Philosophy Hall, Columbia University

Reception will follow