All LogBlog Posts

You probably already know about the two packages that you can use to typeset Fitch-style natural deducation proofs in LaTeX.  Here's another, which you may be interested in if you use Barker-Plummer, Barwise, and Etchemendy's popular logic text Language, Proof, and Logic. It makes proofs like this:

I've taken Etch's original style file and Dave's documentation, put it together in standard docstrip format, cleaned up the code a bit and added a few features.  You can download the beta from

https://github.com/rzach/lplfitch

I've also attached the documentation here.

Please file any problem reports on github, if you could, or email me directly. (The comment system here is unreliable.)  I'm hoping to put it on CTAN in a month.

If you're in Austin, you probably know this already. If you're not, it's probably too late. But this is what I'll be doing this weekend:

Friday, 26 April 2012
Thomas Uebel, University of Manchester, “The Logic of Science and the Pragmatics of Science: The Challenge of Complementarity.”
Christopher French, University of British Columbia, “Carnap, Jeffrey and Explication of Radical Probabilism.”
Sebastian Lutz, Ludwig-Maximilians-Universität München, “The Criteria for the Empirical Significance of Terms.”
Saturday, 27 April 2012
Sahotra Sarkar, University of Texas, “Nagel on Reduction.”
Michael Stoeltzner, University of South Carolina, “Could Mathematical Physics serve as a Model for Formal Epistemology?”
Flavia Padovani, Drexel University, “Reichenbach On Causality in 1923: One Word, Many Concepts”
Richard Zach, University of Calgary, “Carnap on Logic.”

Thanks to Sahotra Sarkar for putting this together!

Have you ever given a presentation at a conference using your laptop, and then were annoyed that you had to carry aroudn the thing for the entire rest of the evening?  It happens to me all the time. By which I mean, once in a great while, but I nevertheless though it would be cool if I could give my presentation just from my phone (a Samsung Nexus).  Just in case I can help other mathematicians/philosophers/scientists with either a bad back or a tendency to leave bags in restaurants, here's how I did it:

• Get the phone to talk to the projector. For that you need a microUSB-to-VGA adaper, or, for versatility, a microUSB-to-HDMI plus a HDM-to-VGA adapter. In the latter case you can plug into the HDMI port on the projector if you have it. I got this and this but I'm sure there are other options.
• Get a longer power cord or simply a longer USB-to-microUSB cable.  The microUSB-to-HDMI adapter is powered and you don't want the phone to be suspeded between the power outlet and the projector. Don't forget your power adapter.
• Get a Bluetooth mouse/clicker thing, since swiping from slide to slide on the phone is a drag. I got this one.
• My presentations are produced with the beamer package for LaTeX, which produces PDF. So I need a PDF viewer app which displays the PDF properly (centered, full screen, no controls), transitions from slide to slide without delay or silly page flip effects, and reacts to the clicker.  This was actually the hardest part, but the OfficeSuite PDF Viewer works fine.  If you use PowerPoint or something like it, you'll have to look for something that does that.
• When you actually give the presentation, you don't want to be interrupted by text messages or phone calls.  So turn airplane mode on. But you need the clicker, so turn Bluetooth back on. Luckily, this is possible.

New entry in the Stanford Encyclopedia:
Logical Pluralism

We train professional philosophers. Sadly, there aren't enough philosophy jobs to go around, and it's hard to pursue a career in philosophy if you can't move to wherever you find a job.  Fortunately, philosophers have transferable skills that are in high demand. Prospective employers just don't associate these skills with "Ph.D. in philosophy".  The challenge is to overcome this.
Mike Steiner wrote a fine dissertation on an anti-realist theory of natural kinds under Marc Ereshefsky's supervision. He won national scholarships. He had good chances at finding an academic job. But he couldn't leave Calgary for family reasons. Now he's working in Oil and Gas (!) and is very happy.  He has some advice for you if you're in a similar position.

The ASL Committee in Logic Education organized a thought-provoking session this morning at the APA Central Division in New Orleans.  There were four presentations and a lively discussion.  What are your thoughts?

Andy Arana started things off with observations about salient differences between what we do in intro logic classes vs. what, e.g., mathematics departments do in "discrete mathematics" classes. Discrete math classes, he points out, serve disciplinary ends in mathematics: students learn concepts and techniques that they then go on to use all the time in advanced math courses (e.g., functions and relations, induction).  By comparison, logic courses do not serve the same disciplinary ends.  Sure, we use arguments all the time in philosophy and sometimes it comes in handy to know that you have to watch the order of your quantifiers or that affirming the consequent is invalid.  But much of what we do in introductory formal logic courses does not get used outside of more advanced formal logic courses.  Our courses are also very often enrolled by non-majors who satisfy a quantitative reasoning requirement. This raises the important question: why do we teach intro logic the way we do? What concepts and methods do majors and non-majors acquire in our logic courses, and do we teach them the right way for them to get these?

Danielle Macbeth gave an interesting pitch for her particular way of teaching intro logic: as a a history course, reading Aristotle, Kant, Wittgenstein, Frege. She made the provocative claim that formal logic has failed to solve philosophical problems (certainly to the extent that, say, Russell, thought it would). To make logic again of value to a philosophical education, she argued, we should focus on the philosophical advances  through a study of its history and specifically of the clarification of the nature of denotation, predication, and the quantifiers. This is, I thought, an interesting persepective: unfortunately it probably can replace intro logic courses only at elite liberal arts colleges where a class with 20 students is "large". But wonderful idea for a more advanced course for majors!

Audrey Yap spoke about stereotype threat in the logic classroom.  This is by now a well-worn topic in math and other STEM fields, especially as concerns gender.  If students see themselves as belonging to a group that is stereotypically bad at something, they will perform worse.  As math and logic are male-dominated and are stereotyped as male (logic even more so than math, perhaps), this is a big issue in the logic classroom, especially when many students take logic in lieu of a mathematics course to fulfil a requirement. What I didn't know about is that another important factor is that even if role models are available, unless succeeding in the field like them is seen as attainable, they hurt rather than help. Math and logic to an extent are like that: if students think you have to be a genius to "get" logic rather than just hard work, it will hurt rather than hinder.  Role models are only helpful if students see them as possible futures.  The message it took from this is that we should emphasize that logic takes hard work, and possibly present role models (female, of colour) who are successful perhaps not as "genius" logicians but through hard work in something our students aspire to but for which logic was an important preparation.

Susan Vineberg brought it back to Andy's point that we should at least keep in mind, if not actually incorporate into our classroom practice, the application of the methods logic courses train students in.  She also compared logical reasoning to mathematical reasoning: in philosophy, like in mathematics, thinking about extreme and near extreme cases is a good strategy to find counterexamples. Other strategies that are useful: partitioning a problem space into cases, considering uniqueness after proving existence, generalizing a result, and self-reference. (E.g., suppose X is real means: X is mind-independent.  Now take X = minds.)

In the ensuing discussion, a lot of other topics came up, including, of course, the perennial question of textbooks (Andy pointed out that while, e.g., basically everyone teaches topology from Munkres, everyone basically hates every logic textbook to some degree and they continue to proliferate). Andy also stressed the importance of logic courses for philosophy departments as their highest enrolment classes and hence a crucial part in the administrative justification of the existence of philosophy programs at many schools (and the threat to it would/will pose if logic instructions moves online). This reminded me of a study I've read, possible an Australian education MA thesis from 10 years ago or so, that investigated the effect philosophy (or humanities?) courses had on the improvement of critical thinking skills in undergraduates -- and which, IIRC, showed that only formal logic courses actually did.  Please tell me if you know what I'm thinking of, Google is no help! Found it! Claudia Álvarez, "Does philosophy improve critical thinking," MA thesis, University of Melbourne, 2007

All six of last year's lectures we had at Calgary's Turing Year series are now available for you to watch on mathtube.org. Thanks again to PIMS for videotaping, editing, and hosting them!  The full list:

John R. Ferris: Alan Turing and Enigma

Central to Alan Turing's posthumous reputation is his work with British codebreaking during the Second World War. This relationship is not well understood, largely because it stands on the intersection of two technical fields, mathematics and cryptology, the second of which also has been shrouded by secrecy. This lecture will assess this relationship from an historical cryptological perspective. It treats the mathematization and mechanization of cryptology between 1920-50 as international phenomena. It assesses Turing's role in one important phase of this process, British work at Bletchley Park in developing cryptanalytical machines for use against Enigma in 1940-41. It focuses on also his interest in and work with cryptographic machines between 1942-46, and concludes that work with them served as a seed bed for the development of his thinking about computers.

Przemysław Prusinkiewic: Alan Turing and the Patterns of Life

In 1952, Turing published his only paper spanning chemistry and biology: "The chemical basis of morphogenesis". In it, he proposed a hypothetical mechanism for the emergence of complex patterns in chemical reactions, called reaction-diffusion. He also predicted the use of computational models as a tool for understanding patterning. Sixty years later, reaction-diffusion is a key concept in the study of patterns and forms in nature. In particular, it provides a link between molecular genetics and developmental biology. The presentation will review the concept of reaction-diffusion, the tumultuous path towards its acceptance, and its current place in biology.

Chris Waters: Alan Turing, the Politics of Sexual Science, and the Making of a Gay Icon

In the 1940s Alan Turing’s homosexuality was an open secret amongst his co-workers at Bletchley Park. In 1952 the secret became widely known when Turing was arrested on charges of “gross indecency” under the same 1885 law that had led to the imprisonment of Oscar Wilde over half a century earlier. Opting for chemical “treatment” of his “condition” rather than imprisonment, Turing was one of many well-known casualties of a heightened drive against homosexuality in a postwar Britain that drew the line between the normal and the deviant more sharply than ever before. In his talk, Chris Waters will discuss Turing’s sexual proclivities and their meanings in the context of his times, focusing in particular on his arrest and subsequent fate in the context of the sexual politics of the first half of the 1950s. In addition, he will discuss the shaping of Turing’s posthumous reputation, beginning with the attempts made by the Gay Liberation Front in the 1970s to render Turing the gay icon he has become today.

Michael R. Williams: Turing's Real Machines

While Turing is best known for his abstract concept of a "Turing Machine," he did design (but not build) several other machines - particularly ones involved with code breaking and early computers. While Turing was a fine mathematician, he could not be trusted to actually try and construct the machines he designed - he would almost always break some delicate piece of equipment if he tried to do anything practical. The early code-breaking machines (known as "bombes" - the Polish word for bomb, because of their loud ticking noise) were not designed by Turing but he had a hand in several later machines known as "Robinsons" and eventually the Colossus machines. After the War he worked on an electronic computer design for the National Physical Laboratory - an innovative design unlike the other computing machines being considered at the time. He left the NPL before the machine was operational but made other contributions to early computers such as those being constructed at Manchester University. This talk will describe some of his ideas behind these machines.

Nicole Wyatt: Turing and Intelligent Machines

Turing's interest in the possibility of machine intelligence is probably most familiar in the form of the 'Turing Test', a version of which has been instantiated since 1991 as the Loebner Prize in Artificial Intelligence. To this date the Loebner Gold Medal has not been won. But should any future winner of the prize count themselves as having created a computer that thinks? Turing's 1950 Mind paper 'Computing Machinery and Intelligence', gives a sustained defence of the claim that a machine able to pass the test, which Turing called the Imitation Game, would indeed qualify as thinking. This lecture will explain the Turing Test as well as Turing's more general views concerning the prospects for artificial intelligence and examine both the criticisms of the test and Turing's rebuttals.

Richard Zach: Alan Turing and the Decision Problem

Many scientific questions are considered solved to the best possible degree when we have a method for computing a solution. This is especially true in mathematics and those areas of science in which phenomena can be described mathematically: one only has to think of the methods of symbolic algebra in order to solve equations, or laws of physics which allow one to calculate unknown quantities from known measurements. The crowning achievement of mathematics would thus be a systematic way to compute the solution to any mathematical problem. The hope that this was possible was perhaps first articulated by the 18th century mathematician-philosopher G. W. Leibniz. Advances in the foundations of mathematics in the early 20th century made it possible in the 1920s to first formulate the question of whether there is such a systematic way to find a solution to every mathematical problem. This became known as the decision problem, and it was considered a major open problem in the 1920s and 1930s. Alan Turing solved it in his first, groundbreaking paper "On computable numbers" (1936). In order to show that there cannot be a systematic computational procedure that solves every mathematical question, Turing had to provide a convincing analysis of what a computational procedure is. His abstract, mathematical model of computability is that of a Turing Machine. He showed that no Turing machine, and hence no computational procedure at all, could solve the Entscheidungsproblem.

The first half of our Alan Turing Centenary lecture series is over, and we've got all three of our talks up on mathtube.org.  You can skip the first one, it's pretty boring, but Mike Williams on early computers and John Ferris on Turing and WWII codebreaking are well worth your time!

It's Alan Turing's centenary, and we've been celebrating it at the University of Calgary with a series of lectures.  This term, we've had a talk on the decision problem, one (by Mike Williams) on Turing and early electronic comupters, and one coming up on March 27, by John Ferris, on Alan Turing and codebreaking in WWII.  Yesterday, we screened the biopic Breaking the Code, with Derek Jacobi as Alan Turing (which you can watch on YouTube in its entirety!). The Pacific Institute for the Mathematical Sciences is paying to have the lectures videotaped and the'll be appearing on mathtube.org as they become available.  The lecture by my distinguised colleague in the Computer Science department, Mike Williams, was just posted a couple of days ago.  Mike is a former President of the IEEE Computer Society, editor in chief of the Annals of the History of Computing, and head curator for the Computer History Museum.  So he knows his history of computing machinery, and gave us a wonderful talk about Turing's role in the development of early digital computers.  (There's also a lecture by me on the 1936 paper, but that's much less interesting.) Thanks to generous funding from the Faculty of Science, we also have nice posters, like the one below, advertising our last talk for the Winter term, by my distinguished colleague in the History Department, John R. Ferris. 

Been waiting a while for this to become official, which it now is: we're hiring. In case you don't know, the CRC program is Canada's effort to attract outstanding foreigntalent to Canada. So there is no preference for Canadians, you get atop-up to your salary, and the teaching load is 1-1. 

Tier I Canada Research Chair in Logic and the Philosophy of Science

The Department of Philosophy at the University of Calgary invites applications and nominations for a Tier I Canada Research Chair in Logic and the Philosophy of Science. The Canada Research Chairs program has been established by the Government of Canada to enable Canadian universities to foster excellence in research and teaching. Further information on the program is available on the CRC website at www.chairs.gc.ca.

We are seeking an established scholar and a leader in any area of logic or the philosophy of science. The successful candidate will have an outstanding record of research, teaching and graduate supervision, and an innovative research program. The appointment, at the rank of Associate Professor or Professor, is expected to start on July 1, 2013.

Specific inquiries about this position may be directed to:

Ali Kazmi, Head
Department of Philosophy
University of Calgary
Email: akazmi@ucalgary.ca

All Chairs are subject to review and final approval by the CRC Secretariat. Applications including a CV, a writing sample, a teaching dossier, and a description of a 7 year research plan, and names and contact information of three referees may be sent to:

Merlette Schnell, Manager
Department of Philosophy
University of Calgary
2500 University Drive NW
Calgary, Alberta T2N 1N4
CANADA
Email: schnell@ucalgary.ca

Applications will be accepted until the position is filled. Review of the applications will begin on July 9, 2012.