Gaifman: Epistemic and Ontological Problems Concerning Mathematics

Epistemic and Ontological Problems Concerning Mathematics
Haim Gaifman (Columbia University)
Tuesday, April 30, 2013, at 4:15 PM
Fong Auditorium (Boylston Hall 110), Harvard University

Abstract. Philosophy of mathematics is confronted with two major questions: (i) How do we come to know mathematical propositions? (ii) What is the nature of mathematical truth? Attempts to give satisfactory answers to one of the questions have resulted in unsatisfactory accounts regarding the other. I shall outline an approach intended to do justice to both questions. This is an ongoing work.

Dogramaci: The Varieties of Validity Worth Wanting

The Varieties of Validity Worth Wanting
Sinan Dogramaci  (Texas)
Thursday, April 11th, 4:10 PM
716 Philosophy Hall, Columbia University

Abstract. I ask whether the validity of a Modus Ponens inference is any part of the explanation of why the inference is, in any sense, a good or valuable inference. I argue for the following. On the orthodox understanding of validity, a semantic understanding, validity has no explanatory relevance to the reasoning’s value. On a metaphysical understanding of validity, one definable in terms of possible worlds, validity is relevant to a partial, but crucially incomplete, explanation of the reasoning’s value. The complete explanation of the reasoning’s value must also appeal to a substitutional understanding of validity, a notion once advocated by Quine.

van Benthem: Logic in Games

Logic in Games
Johan van Benthem (Amsterdam/Stanford)
Thursday, November 15, 2012, 4:10 – 6:00 PM
716 Philosophy Hall, Columbia University

Abstract. In recent decades, logic has been applied in the foundations of game theory, and this makes sense as a capping stone for the philosophical logic tradition of studying various dimensions of information-driven agency. But at the same time, the core notions of logic themselves can be cast as games, and a thriving theory has sprung up around this perspective, especially at interfaces with computer science. I will compare these two perspectives of logic of games versus logic as games, discuss some results about their connections, and raise the question what this contrast tells us about logic.

Reception to follow

CFP: The Constructive in Logic and Applications

May 23-25, 2012, detailed program here.
CUNY Graduate Center, 365 Fifth Avenue, New York City.

Constructivity is fundamental to the application of mathematics to the real world, whether in the exact sciences, the social sciences, or engineering. Constructive logics supporting this tradition have flourished over the last century. This conference is a celebration of the past and future of the constructive tradition. Distinguished logician Sergei Artemov is 60. He has made fundamental contributions exploring constructivity in logic, computer science, epistemology, game theory, and other areas. With this conference we honor his work, and by extension a subject whose content he has elucidated and whose boundaries he has expanded.

Scientific Committee: Anil Nerode (Cornell) and Melvin Fitting (CUNY)
Web page:
Participants are invited to register, the registration is free.
Contact email:

The confirmed speakers are:
Arnon Avron (Tel Aviv University)
Adam Brandenburger (New York University)
Sam Buss (University of California San Diego)
Robert Constable (Cornell University)
Solomon Feferman (Stanford University)
Melvin Fitting (City University of New York)
Harvey Friedman (Ohio State University)
Haim Gaifman (Columbia University)
Dexter Kozen (Cornell University)
Victor Marek (University of Kentucky)
Robert Milnikel (Kenyon College)
Joan Moschivakis (University of California Los Angeles)
Yiannis Moschovakis (University of California Los Angeles)
Pavel Naumov (McDaniel College)
Anil Nerode (Cornell University)
Rohit Parikh (City University of New York)
Vaughan Pratt (Stanford University)
Jeff Remmel (University of California San Diego)
Bryan Renne (University of Amsterdam)
Gerald Sacks (Harvard University /Massachusetts Institute of Technology)
Andre Scedrov (University of Pennsylvania)
Johan van Benthem (University of Amsterdam/Stanford University)

The Unity and Diversity of Logic

Panel discussion: the unity and diversity of logic
Friday, March 9, 2012 4:45 pm GC 4102 (Science Center) 60 minutes

Abstract. The field of mathematical logic sometimes seems to be fracturing into ever-finer subdisciplines, with little connection between them, and many logicians now identify themselves by their specific subdiscipline. On the other hand, certain new themes have appeared which tend to unify the diverse discoveries of the many subdisciplines. This discussion will address these trends and ask whether one is likely to dominate the other in the long term. Will logic remain a single field, or will it split into many unrelated branches?

The panelists will be Prof. Gregory Cherlin, Prof. Joel David Hamkins, Prof. Rohit Parikh, and Prof. Jouko Väänänen, with the discussion moderated by Prof. Russell Miller. Questions and participation from the audience are encouraged.

Reposted from here.