Formal Philosophy

Logic at Columbia University

Price: Heart of DARCness

by Robby

Heart of DARCness
Huw Price (University of Cambridge)
4:10 pm, Thursday, October 13th, 2016
Faculty House, Columbia University

Abstract. Alan Hajek has recently criticised the thesis that Deliberation Crowds Out Prediction (renaming it the DARC thesis, for ‘Deliberation Annihilates Reflective Credence’). Hajek’s paper has reinforced my sense that proponents and opponents of this thesis often talk past one other. To avoid confusions of this kind we need to dissect our way to the heart of DARCness, and to distinguish it from various claims for which it is liable to be mistaken. In this talk, based on joint work with Yang Liu, I do some of this anatomical work. Properly understood, I argue, the heart is in good shape, and untouched by Hajek’s jabs at surrounding tissue. Moreover, a feature that Hajek takes to be problem for the DARC thesis – that it commits us to widespread ‘credal gaps’ – turns out to be a common and benign feature of a broad class of cases, of which deliberation is easily seen to be one.

More about the seminar here.

We will be having dinner right after the meeting at the faculty house. Please let Robby know if you will be joining us so that he can make an appropriate reservation (please be advised that at this point the university only agrees to cover the expenses of the speaker and the rapporteur and that the cost for all others is $30, payable by cash or check).

Diaconis: The Problem of Thinking Too Much

by Yang Liu

The Problem of Thinking Too Much

Persi Diaconis (Stanford University)
4:10 pm, Friday, September 16, 2016
Faculty House, Columbia University

Abstract. We all know the problem: you sit there, turning things over, and nothing gets done.  Indeed, there are examples where “quick and dirty,” throwing away information, dominate.  My examples wil be from Bayesian statistics and the mathematics of coin tossing, but I will try to survey some of the work in psychology, philosophy, and economics.

More about the seminar here.

We will be having dinner right after the meeting at the faculty house. Please let Robby know if you will be joining us so that he can make an appropriate reservation (please be advised that at this point the university only agrees to cover the expenses of the speaker and the rapporteur and that the cost for all others is $25, payable by cash or check).


Conference on Reconciling Nominalism and Platonism

by Yang Liu


Department of Philosophy, Columbia University
April 22–23, 2016

FRIDAY APRIL 22 (Philosophy Hall, Room 716)

Achille Varzi (Columbia University), Marco Panza (IHPST)
Welcome and Introduction
John Burgess (Princeton University)
Reconciling Anti-Nominalism and Anti-Platonism in the Philosophy of Mathematics
15:45–16:00 Break
Haim Gaifman (Columbia University)
Reconfiguring the Problem: “Platonism” as Objective, Evidence-transcendent Truth
Sébastien Gandon (Université Blaise Pascal)
Describing What One is Doing. A Philosophy of Action Based View of Mathematical Objectivity

SATURDAY, APRIL 23 (Philosophy Hall, Room 716)

Mirna Džamonja (University of East Anglia and IHPST)
An Unreasonable Effectiveness of ZFC Set Theory at the Singular Cardinals
11:00–11:30 Break
Hartry Field (New York University)
Platonism, Indispensability, Conventionalism
13:00–15:00 Lunch
Justin Clarke-Doane (Columbia University)
The Benacerraf Problem in Broader Perspective
16:30–17:00 Break
Michele Friend (George Washington University)
Is the Pluralist Reconciliation between Nominalism and Platonism too Easy?
18:30 Conclusions

Workshop on Group Agency and Social Epistemology

by Robby


Date: April 2nd, 10:00.  Location: Phil 716.

Philip Kitcher
Social Agnotology

Agnotology stands to ignorance as epistemology stands to knowledge. This talk will be focused on social mechanisms that sustain ignorance. Some forms of ignorance are fruitful. Most are not. I begin with some distinctions. Those distinctions are then used to consider particularly noxious (and live) forms of contemporary ignorance: specifically, kinds of ignorance that persist in spite of knowledgeable people within the community, and that endure because those who remain ignorant cannot tell who is expert with respect to an important debated issue (example – confusions about anthropocentric climate change). I argue that the intellectual credit economy, useful in sustaining valuable diversity within the scientific community, interacts with other valuable social conditions (wide recognition that scientists should inform the general public) to erode the markers of epistemic authority on which all of us depend.

Cailin O’Connor
Power, Bargaining, and Evolution

Nash famously showed that power differences across players in game theoretic models can translate into advantages in bargaining scenarios. In this talk, I discuss joint work with Justin Bruner where we explore how power, hashed out in several different ways, can lead to bargaining advantage in evolving social populations. I show how these models can inform the emergence of norms of collaboration across hierarchies in academia, and other bargaining norms in populations with more and less powerful groups.

Gregory Wheeler
Mispriced gambles: What peers learn when they disagree

The Preservation of Irrelevant Evidence (PIE) Principle maintains that a resolution strategy to peer disagreements should be able to preserve unanimous judgments of evidential irrelevance among the peers. It is well-known that no standard Bayesian resolution strategy satisfies the PIE Principle, and some — such as Carl Wagner — have argued so much the worse for PIE. In this paper we respond by giving a loss aversion argument in support of PIE and against Bayes. Another response is for each peer to dig in her heels and remain ‘steadfast’ or cave-in to a single dictator. Thomas Kelly advocates the former approach and nobody, so far as I know, the latter. In any case, we respond by arguing that a disagreement introduces to the peers the serious possibility that they may have mispriced the random quantities in dispute. The theory of imprecise probability offers tools to clear up these matters, but it also uncovers new issues that are unfamiliar to standard probabilistic modelings for a single agent. Thus, we introduce the notion of a set-based credal judgment to frame and address some of that subtleties that arise in peer disagreements.

Kevin Zollman
The credit economy and the economic rationality of science

Scientists are motivated by the credit they are given for their discoveries by their peers. Traditional theories of the scientific method in philosophy do not include this motivation, and at first blush it appears as though these theories would regard it as inappropriate. A number of scholars have suggested, however, that this motivation serves to perpetuate successful science. It has been proposed as a mechanism to encourage more scientific effort and a mechanism to effectively allocate resources between competing research programs. This paper presents an economic model of scientists’ choices in which these claims can be formalized and evaluated. Ultimately, the paper comes to mixed conclusions. The motivation for credit may help to increase scientists effort in science, but also may serve to misallocate effort between competing research programs.

Easwaran: A New Framework for Aggregating Utility

by Robby

A New Framework for Aggregating Utility
Kenny Easwaran (Texas A&M University)
4:10 pm, Friday, March 11, 2016
Faculty House, Columbia University

Abstract. It is often assumed that a natural way to aggregate utility over multiple agents is by addition. When there are infinitely many agents, this leads to various problems. Vallentyne and Kagan approach this problem by providing a partial ordering over outcomes, rather than a numerical aggregate value. Bostrom and Arntzenius both argue that without a numerical value, it is difficult to integrate this aggregation into our best method for considering acts with risky outcomes: expected value.

My 2014 paper, “Decision Theory without Representation Theorems”, describes a project for evaluating risky acts that extends expected value to cases where it is infinite or undefined. The project of this paper is to extend this methodology in a way that deals with risk and aggregation across agents simultaneously, instead of giving priority to one or the other as Bostrom and Arntzenius require. The result is still merely a partial ordering, but since it already includes all considerations of risk and aggregation, there is no further need for particular numerical representations.

Floyd: Gödel on Russell

by Yang Liu

Gödel on Russell: Truth, Perception, and an Infinitary Version of the Multiple Relation Theory of Judgment
Juliet Floyd (Boston University)
4:10 pm, May 8, 2014
Faculty House, Columbia University