We have some new editors at the Journal for the History of Analytic Philosophy.

First Announcement & Call for Abstracts Logic Colloquium 2015European Summer Meeting of the Association for Symbolic Logic Helsinki, Finland, 3-8 August 2015 http://www.helsinki.fi/lc2015 The annual European Summer Meeting of the Association for Symbolic Logic, the Logic Colloquium 2015 (LC 2015), will be organized in Helsinki, Finland, 3-8 August 2015. Logic Colloquium 2015 is co-located with … Continue reading CfP: 2015 Logic Colloquium in Helsinki

Sad news from Philip Welch at Bristol:  John Shepherdson has died. I deeply regret having to impart the very sad news that John Shepherdson died in Bristol on Thursday of an inoperable sarcoma. John was a founder of the BLC (together with Robin Gandy if I remember rightly). His own work was in many areas, … Continue reading John Shepherdson, 1926-2015

Every mathematician and philosopher should watch this video by Sarah-Jane Leslie (Philosophy, Princeton) on her study with Andrei Cimpian (Psych, Illinois). Takes just 11 minutes. [youtube https://www.youtube.com/watch?v=FM6mbSiD3eA] Then you can go and read the original study in Science or any of the writeups in, e.g., the Science news blog, Chronicle, Daily Nous, etc.

The Stanford Encyclopedia of Philosophy now has entries on: Negation (Laurence R. Horn and Heinrich Wansing) Disjunction (Ray Jennings and Andrew Hartline) Indicative Conditionals (Dorothy Edgington) Quantifiers and Quantificiation (Gabriel Uzquiano) Identity (Harold Noonan and Ben Curtis)

I learned today that Ivor Grattan-Guinness, the historian of mathematics and logic, died last month. Obituaries: Guardian BibNum

If you're using BibTeX and LaTeX and are doing any kind of scholarly/humanistic work, I'm sure you've run into this annoying problem: BibTeX always complains when a book has both an author and an editor. That's a problem when, say, you want to include Gödel, K., 1986. Collected Works, vol. I. S. Feferman et al., … Continue reading Nerlim: a Master Bibliography Style that Allows Books to have both Authors and Editors

New in the Review of Symbolic Logic (part 1, part 2) A Gödel sentence is often described as a sentence saying about itself that it is not provable, and a Henkin sentence as a sentence stating its own provability. We discuss what it could mean for a sentence of arithmetic to ascribe to itself a … Continue reading Halbach & Visser: Self-reference in arithmetic

[View the story "Michael Beaney's Vienna Circle Lecture on Susan Stebbing" on Storify]

In response to my post about "lesser known Russian/Soviet logicians", Lev Beklemishev commented: Dirk van Dalen was interested in Shatunovsky's work and at his request I procured a copy of his book on the development of algebra on the basis of what can be called rudimentary constructivist ideas. This was, of course, pre-Brouwerian, and the … Continue reading More on Shatunovsky, Kagan, and Yanovskaya

I'm working on a paper that features Moses Schönfinkel, so I was reading through a manuscript of his where he rattles off a long list of important logicians.  In addition to the usual suspects, it features the names "Schatunowski, Sleschinski, Kahan, Poretski."  I spent the better part of a day trying to figure out to … Continue reading Some Lesser Known (to me) Russian/Soviet Logicians

Shawn Standefer has done us all a great service by starting and populating a Wiki of PhD programs in Philosophical Logic! This wiki provides an unranked list of PhD (and (eventually) terminal M.A.) programs that have strengths in philosophical logic. Links are provided to the websites, CVs, and PhilPapers profiles of the relevant faculty at … Continue reading Graduate Programs in Philosophical Logic

...is another's modus tollens. [W]hen I was nine years old, I came down with scarlet fever. [...] During that year there was nothing in the world which I wanted so much as a bicycle. My father assured me that when I got well I would get one but, childlike, I interpreted this as meaning that … Continue reading One person’s modus ponens…

Interpreting Gödel: Critical Essays, edited by Juliette Kennedy, was just published by Cambridge. It looks extremely interesting, with an all-star cast of contributors: Introduction: Gödel and analytic philosophy: how did we get here? Juliette Kennedy Part I. Gödel on Intuition:2. Intuitions of three kinds in Gödel's views on the continuum, John Burgess 3. Gödel on … Continue reading Kennedy’s Interpreting Gödel Out Now

Gödel's incompleteness theorems have many variants: semantic vs. syntactic versions, which specific theory is taken as basic, what model of computability is used, which logical system is assumed to underlie the provability relation, how syntax is arithmetized, what hypotheses the theorem itself uses (soundness, consistency, $latex \omega$-consistency, etc.). These result in trade-offs regarding simplicity of … Continue reading Two New(ish) Surveys on Gödel’s Incompleteness Theorems

Via the APMP list: Expressions of interest are invited for a postdoc grant (financed by Junta de Andalucia) associated with the following research project:  “THE GENESIS OF MATHEMATICAL KNOWLEDGE: COGNITION, HISTORY, PRACTICES” (P12-HUM-1216). IP: Jose Ferreiros Contact: josef@us.es The grant consists in a 2-year research contract to be held at the University of Sevilla. Salary … Continue reading Possible Postdoc on Genesis of Mathematical Knowledge

Dana Scott's proof reminded commenter "fbou" of Kalmár's 1935 completeness proof. (Original paper in German on the Hungarian Kalmár site.) Mendelsohn's Introduction to Mathematical Logic also uses this to prove completeness of propositional logic. Here it is (slightly corrected): We need the following lemma: Let $latex v$ be a truth-value assignment to the propositional variables … Continue reading Kalmár’s Compleness Proof

Last week I gave my decision problem talk at Berkeley. I briefly mentioned the 1917/18 Hilbert/Bernays completeness proof for propositional logic. It (as well as Post's 1921 completeness proof) made essential use of provable equivalence of a formula with its conjunctive normal form. Dana Scott asked who first gave (something like) the following simple completeness … Continue reading Dana Scott’s Favorite Completeness Proof

Back in 2009, I taught a short course on the epsilon calculus at the Vienna University of Technology.  I wrote up some of the material, intending to turn them into something longer.  I haven't had time to do that, but someone might find what I did helpful. So I put it up on arXiv: http://arxiv.org/abs/1411.3629