My former colleague Charlie Martin died last Thursday. He was a major figure in metaphysics, one of the first to talk about truthmakers.Obituaries here and here.

The venerable Swedish philosophy journal Theoria is published by Blackwell since this past March, and that means it is online, including the back issues. I'm not sure of the exact dates, but in the 70s, when Krister Segerberg was the editor-in-chief of that journal, Theoria was the place to publish modal logic and formal philosophy. … Continue reading Theoria Online (Including Back Issues!)

One very common informal statement of Gödel's theorem is that it shows that for any (sufficiently strong consistent blah blah) formal system, there are truths that it can't prove. And if you don't formulate Gödel's incompleteness theorem that way, at least you state this as a corollary: Gödel's theorem shows that truth and provability (in … Continue reading Tarski on Gödel’s Theorem and the Deductive Method

Today's Dinosaur Comics was written by xkcd's Randall Munroe:Ryan North, the author of Dinosaur Comics, has used philosophical/logical themes in his comic as well, e.g., the Twin Earth comic, or the Post Hoc Ergo Propter Hoc comic, or the one on pragmatism. This one is pretty funny, too.Of course, you've all seen the xkcd comic … Continue reading Zeno’s Paradox at Dinosaur Comics

Update on my old post on modal logic textbooks: Two new modal logic books I have recently come across: Nino B. Cocchiarella and Max A. Freund, Modal Logic: An Introduction to its Syntax and Semantics (Oxford, 2008)Walter Carnielli and Claudio Pizzi, Modalities and Multimodalities (Springer, 2008) Anyone already read these and have an opinion? The … Continue reading New Modal Logic Books

If you're going to be in Pittsburgh (at the PSA) in three weeks, please come to the Carnap Reception that Open Court is going to throw on Friday, Nov 7. I think it'll be at 5:30. Vol. 1 of Carnap's Collected Works will be presented. I expect there will be free drinks, too!

Theorem(e)'s, that is, Henri Galinon's, page of links to free, online logic textbooks and survey texts has moved and is now updated.

Since I'm hanging out with a bunch of category theorists every Wednesday, web finds with "category theory" in them keep attracting my attention. A couple of weeks ago, I came across this book draft posted on arXiv: Atish Bagchi and Charles Wells, Graph-based Logic and Sketches At first I thought, cool!, a new book on … Continue reading Logic and Category Theory

Are you sitting in front of the computer, hitting the "reload" button every two seconds to see if the October Jobs for Philosophers is posted on the APA website yet? Why not check out the job that we have right here: Assistant Professor with AOS in Logic?UPDATE: Hm, looks like there aren't many logic jobs … Continue reading Jobs for Logicians

Today I taught Ch. 13 of Peter Smith's book. We showed that every Σ1 function can be written as a composition of two Δ0 functions (p. 108). In his proof of this, Peter's following Boolos Burgess & Jeffrey (Lemma 16.12 on p. 206 of the 4th & 5th ed.; it's not in the 3rd so … Continue reading Why is Every Σ1 Function a Composition of Two Δ0 Functions?

NB: History and philosophy of computation explicitly part of the scope. Note also the philosophers on the program committee and the special session on philosophical and mathematical aspects of hypercomputation.CiE 2009: COMPUTABILITY IN EUROPE 2009 -Mathematical Theory and Computational PracticeHeidelberg, Germany19 - 24 July 2009Deadline for submissions: 20 JANUARY, 2009 http://www.math.uni-heidelberg.de/logic/cie2009/ CiE 2009 is the … Continue reading CfP: Computability in Europe 2009

So I got fed up with Bloglines one time too many, and I switched to Google Reader. It maybe it's just that I'm still getting used to it, but I find the user interface of Bloglines a bit more intuitive. And it has served me well for years. Wait--Why do I feel bad about switching … Continue reading Blog Changes

If you're a member of the ASL,* you recently received the September Newsletter. In it--maybe easy to miss--this nice opportunity to acquire some logic books for cheap: For a limited time, the ASL is making available the following volumes from its book series at an additional discount.Lecture Notes in Logic (each volume $12 for ASL … Continue reading Hájek/Pudlák for Cheap

From Theorem(e): Nuel Belnap now has two logic texbook drafts on his webpage :Notes on the Art of Logic (.pdf, 310 p.)Notes on the Science of Logic (.pdf, 237p.) The first is an intro to logic, with truth table method, natural deduction proofs, etc., the second a course on metalogic, with completeness proofs.I did mention … Continue reading Belnap, Art and Science of Logic