University of Calgary

# All LogBlog Posts

## Most Logical Countries in the World

Submitted by Richard Zach on Tue, 07/14/2009 - 7:49pm

For your amusement: a list of all countries with at least 5 members of the Association for Symbolic Logic, rank-ordered by number of logicians per 10,000,000 inhabitants. Bonus info: percentage of women logicians in these countries.

 Country # ASL members % Women per 10,000,000 New Zealand 17 0% 39.5 Switzerland 25 4% 32.5 Israel 22 18% 29.7 Norway 13 0% 27.1 USA 806 12% 26.3 Netherlands 43 21% 26.1 Canada 85 11% 25.2 Belgium 23 4% 21.5 Finland 10 10% 18.9 United Kingdom 100 10% 16.4 Denmark 9 0% 16.4 Sweden 15 20% 16.3 Singapore 7 17% 14.6 Greece 16 25% 14.3 Austria 11 9% 13.3 Croatia 5 0% 11.4 Germany 87 8% 10.6 Portugal 9 33% 8.5 Australia 17 6% 7.8 Spain 35 11% 7.6 Italy 42 24% 7.0 France 40 11% 6.2 Japan 63 12% 5.0 Czech Republic 5 0% 4.8 Poland 12 8% 3.1 Brazil 40 13% 2.1 Colombia 8 25% 1.8 Argentina 6 33% 1.5 South Africa 6 0% 1.2 Iran 5 0% 0.7 Russia 8 25% 0.6 Mexico 5 20% 0.5 China 14 0.1 India 8 20% 0.1

## Women in Philosophy of Logic and Philosophical Logic

Submitted by Richard Zach on Fri, 06/26/2009 - 4:24pm

Catarina Dutilh Novaes sent the following important message to PHILOS-L last weekend, reposted here with her permission:

Dear all,

Recently (and admittedly very late!), I started thinking more seriously about the lack of gender balance in the areas in which I do most of my research, namely history and philosophy of logic and philosophical logic. What got me thinking was probably the (positive) noise being made at Feminist Philosophers. One of the issues raised by the Feminist Philosophers is the low proportion of women in most philosophy conferences (in particular as invited/keynote speakers); I realized that in the workshop I am organizing, there are only three women as speakers, including myself! So I think this is a matter that deserves further attention.

Richard Zach had a blog entry a while ago on the staggeringly low number of women publishing in the journals of the area (his data concerned the Journal of Philosophical Logic). From this sort of data it is all too easy to conclude that there simply aren't enough women around working in (philosophy of) logic and philosophical logic so as to redress the imbalance seen in conference lineups. But here again the usual analysis applies: the lack of female speakers at such conferences reinforces the idea that the area is just not 'for women', which in turn does not encourage young female students to pursue interests they might have in the area. Absence of female keynote speakers may also be a discouraging factor for other female researchers to submit papers to such conferences. Sally Haslanger has a wonderful piece on how vicious these mechanisms can be, which can be found here: Changing the Ideology and Culture of Philosophy: Not by Reason (Alone)

So the purpose of this message now is to question the widespread impression that there are not (or very few) prominent female logicians and philosophers of logic, people with the standing to be keynote speakers at major conferences. I was thinking it might be useful to compile a list of such people, sort of a handy device that could help those organizing conferences in the area to ensure a better gender balance among the speakers. Please send me names off list, and I will post the results to the whole list once we have a significant number of names. Just to give you an idea of what I have in mind, here are some women that would obviously be on such a list: Juliet Floyd, Penelope Maddy, Gila Sher, Delia Graff Fara. I’m sure there are many more such talented women working in the philosophy of logic and philosophical logic, so I look forward to many reactions!

Thanks!

Catarina
cdutilhnovaes at yahoo dot com

UPDATE: Results of the effort are collected "women in philosophy of logic and philosophical logic" on the Logic and Rational Interaction blog.

## PM@100: Logic from 1910 to 1927

Submitted by Richard Zach on Wed, 06/24/2009 - 1:28am
Call for Papers
PM@100: Logic from 1910 to 1927

21 – 24 May, 2010
Bertrand Russell Research Centre
McMaster University
Hamilton, Ontario

The Bertrand Russell Research Centre in 2010 will host a conference to celebrate the 100th anniversary of the publication of the first volume of Russell and Whitehead’s Principia Mathematica.

The publication in 1910 of the first of the three volumes of Russell and Whitehead’s Principia Mathematica was a landmark in the development of logic, the foundations of mathematics, and the application of logic in philosophy. The rapid development of these fields in the two decades after 1910 owes perhaps more to Principia Mathematica than to any other work. Subsequently, however, its lessons learnt in different ways by different people, it becomes more difficult to determine exactly what the world owes to this gigantic piece of work. Daunting both for its size and its technical difficulty, the book is now known more by reputation than by detailed study. Russell himself maintained, no doubt with some exaggeration, that he knew of only six people besides the authors who had read the entire three volumes. He remained dissatisfied with the foundations of the work and attempted a major revision (this time without Whitehead’s help) in a second edition published in 1925–27, which further complicated its historical legacy.

A century after its first appearance, a great deal has changed. Many of Russell’s working papers on the problems it addressed have been published, and this has led to significant re-interpretations of the work itself. Enough time has now passed to make it possible to evaluate what contributions it made, or failed to make, to philosophy, logic, and the foundations of mathematics.

Presenters Include: Patricia Blanchette, Charles Chihara, Warren Goldfarb, Ivor Grattan-Guinness, Leila Haaparanta, Allen Hazen, David Kaplan, Gregory Landini, Peter Simons, Alasdair Urquhart, and Richard Zach.

Submissions to the conference are sought in all areas relating to Principia Mathematica or to the development of logic and to the philosophy and foundations of mathematics in the years between the two editions.

Contributors are asked to submit two copies of an essay suitable for 30–45 minute presentation with an abstract no later than 1 January 2010 to:

Professor Nicholas Griffin, Director
The Bertrand Russell Research Centre
1280 Main Street West
Hamilton, Ontario

EMAIL: ngriffin@mcmaster.ca
FAX: 905-577-6930

Graduate students are also encouraged to submit. Announcements of acceptances for the program will be made by the end of February 2010.

Conference Co-Organizers:

Nicholas Griffin
The Bertrand Russell Research Centre
McMaster University
ngriffin@mcmaster.ca

Bernard Linsky
Department of Philosophy
University of Alberta
bernard.linsky@ualberta. ca

## Server Problems

Submitted by Richard Zach on Fri, 06/19/2009 - 6:40pm

My website people changed something on the server and now this blog isn't displaying properly and my website is completely down. Sorry. If you want to get to my website, try www.ucalgary.ca/rzach/ instead of www.ucalgary.ca/~rzach/

## Benson Mates, 1919-2009

Submitted by Richard Zach on Tue, 05/19/2009 - 8:11am

Benson Mates, Professor emeritus of Philosophy at the University of California, died May 14. He was a logician, historian of logic, philosopher of language,epistemologist, Leibniz scholar, and author of the excellent logic textbook Elementary Logic.

## Carnap Action in Paris

Submitted by Richard Zach on Sat, 05/16/2009 - 6:34am

In between thinking and lecturing about the epsilon-calculus, I'm in Paris for a few days: it's where all the Carnap action is right now. Heard wonderful talks by the likes of Steve Awodey, Dan Isaacson, Alan Richardson, Erich Reck, Delphine Chapuis-Schmitz, and Tom Uebel, unfortunately missed those by Michael Beaney, Juliet Floyd, and Rick Creath, and looking forward to some by André Carus, Gottfried Gabriel, Peter Hylton, Thomas Morman, and Pierre Wagner today. Thanks to Pierre for putting on this exciting conference!

## Robert K. Meyer, 1932-2009

Submitted by Richard Zach on Sat, 05/09/2009 - 12:47pm

Bob Meyer, emeritus professor of logic and philosophy at ANU, died last Thursday at the age of 77. He worked mainly on relevant logics and entailment, and is remembered not just for his work in logic, but also his wit and humor.

Dave Chalmers and Greg Restall remind us of the paper "God exists!", in which Bob proved that the existence of God is equivalent to the Axiom of Choice, and the Manifesto of the Logician's Liberation League.

UPDATE: Obit from the ASL Newsletter:

Robert Kenneth (Bob) Meyer, a major contributor in the field of non-classical logics, and a central figure on the Australasian logical scene, died in Canberra on May 6, 2009 at the age of 76, after a long struggle with cancer. Before his retirement as Professor in 1998, Meyer spent more than twenty years at the Australian National University, first in Philosophy at the Research School of Social Sciences, and subsequently in the Automated Reasoning Project, of which he was a founder. Meyer was born on May 27, 1932 in Philadelphia. He received a Bachelor of Divinity at Princeton Theological Seminary in 1956. After studying Japanese in Kyoto, he served as a missionary at the Christian Institute of Industrial Relations in Osaka from 1959 to 1962. Impelled by questions about the foundations of his religious beliefs, he enrolled as a graduate student in Philosophy at the University of Pittsburgh, receiving a Ph.D. in 1966 under the supervision of Nuel Belnap. From 1965 to 1974, he taught in Philosophy departments at West Virginia University, Rice University, Bryn Mawr College, Indiana University, and the Universities of Toronto and Pittsburgh. From 1974 until his retirement in 1998, he was at the Australian National University. Meyer served as the President of the Australasian Association for Logic in 1982 and was elected as a Fellow of the Australian Academy of the Humanities in the same year. Meyer was famous for his work in relevant logic and entailment. An early major contribution in the area was his proof (with J.M. Dunn) of the admissibility of the rule $\gamma$ in the logics $R$ and $E$. His best known work in the area is his series of papers with Richard Routley, expounding the relational semantics for relevant logics, and proving completeness theorems and many other results with its aid. Bob Meyer's brilliance as a logician and his infectious enthusiasm stimulated the growth of the Australian school of logic. In the 1980s, the research group surrounding him pioneered the use of computers in investigating logical problems. This group formed the nucleus of the Automated Reasoning Project, that later morphed into the Logic and Computation Group (both at ANU). Bob was noted not only for his enormous and unquenchable enthusiasm for logic, but also for his wit and humour. From 1969 onwards, he was the Maximum Leader of the Logicians Liberation League; for the manifesto of the LLL see http://users.rsise.anu.edu.au/~rkm/manifesto.html. Remarkable also is his contribution to rational theology, "God Exists!'' (published in Noûs 21: 345-61, 1987), in which he proves that God's existence (under a certain interpretation) is equivalent to the Axiom of Choice. Bob is remembered fondly by his family and his many friends and colleagues as a remarkable logician, and a wonderful human being.
Submitted by Richard Zach on Fri, 05/08/2009 - 6:55am

## Vienna Waits For Me

Submitted by Richard Zach on Tue, 05/05/2009 - 3:50am

At least I hope it does. I'll see in a couple of days, when I get there. Scheduled to give a talk on proof interpretations at the Institute Vienna Circle on Thursday (5 pm, Institut für Zeitgeschichte, Uni Wien Campus, Hof 1, 2. Stock, links). Friday, I start teaching a short course on the epsilon calculus at the TU Wien Logic Group. It'll be 10-2 in the seminar room of the department, 185/2, Favoritenstrasse 9, 3rd floor, yellow zone. Both of those will be in English, contrary to what you might think from the content of the linked pages.

## Women in Philosophy Employment Study Online

Submitted by Richard Zach on Wed, 04/29/2009 - 11:15pm

The May 2009 issue of the Proceedings and Addresses of the APA contain an interesting study conducted by the Committee on the Status of Women. It's online on the APA website:

CSW Jobs for Philosophers Employment Study

## 2009 Canadian Research Grants to Philosophers

Submitted by Richard Zach on Wed, 04/22/2009 - 6:42pm

SSHRC has posted the list of funded projects from the most recent Standard Research Grants competition. These grants are for three years. Last year's results are here. (Check the discussion in comments for info on what these grants are for, comparison with NEH grants, etc. UPDATE: Actually, the interesting discussion followed the 2006 list.)

This year's stats: 105 applications (2008: 92; 2007: 88; 2006: 85, 2005: 96, 2004: 92), 32 grants, for a success rate of 30% (2008: 30%; 2007: 29%; 2006: 37%, 2005: 38%, 2004: 48%). Full stats here.

Here's a list of the projects that jumped out at me as being philosophy projects or where I recognized the applicants as philosophers. So, the list is certainly incomplete! I haven't bothered sorting them alphabetically this time: they're sorted by province, east to west, then by university. The list doesn't give the department, nor does it give the grant selection committee, so some of these may have applied to a GSC other than philosophy--I don't think there's a way to tell. As always, please email with corrections and additions, or post in comments. Congratulations to all! And kudos to SSHRC for making the list of results available right away, and not with a delay of several months as in the past.

And a question: is it just my impression, or is Quebec overrepresented in philosophy SSHRC's? 42% of my list from Quebec, but only 27% of overall applications. It wasn't like this in the past few years. Maybe just coincidence? (After all, the prairies got nothing this year, it seems, but we had a pretty good showing last year.)

1. Renaud, François - Université de Moncton $25,787 Cicéron platonicien : la forme du dialogue et le débat entre scepticisme et dogmatisme 2. Charles, Syliane - Bishop's University$44,400
Entre physique et métaphysique, l'individu chez Spinoza
3. Danisch, Robert C. - Concordia University $59,000 Completing the linguistic turn: neopragmatism as rhetorical theory 4. Smith, Justin E.H. - Concordia University$76,874
Nature, human nature, and human difference: philosophical anthropology and the problem of diversity in the new science of nature, 1500-1800
5. Al-Saji, Alia - McGill University $39,957 Vision, race and ethics: a phenomenological investigation of racializing perception 6. Davies, David A. - McGill University$38,625
The ontology of multiple artworks: a performance-theoretic approach
7. Deslauriers, Marguerite L. - McGill University $80,237 Women, rationality and immortality: the reception of Plato and Aristotle in 16th and 17th C. feminist philosophy 8. McGilvray, James A. - McGill University$52,802
Philosophy and biolinguistics
9. Duchesneau, François - Université de Montréal $49,500 Monades et systèmes de la nature : Leibniz et sa postérité 10. Lepage, François - Université de Montréal$45,000
Les systèmes logiques de Lesniewski : une perspective contemporaine
11. Macdonald, Iain - Université de Montréal $35,724 Adorno and Heidegger: history and stakes of an unfinished debate 12. Lacroix, André - Université de Sherbrooke$71,660
Bégin, Luc - Université Laval
La formation chez les praticiens en éthique
13. Fisette, Denis - Université du Québec à Montréal $91,270 La philosophie de Franz Brentano via sa correspondance avec ses étudiants 14. Panaccio, Claude - Université du Québec à Montréal$71,540
Le nominalisme médiéval et l'externalisme : ontologie et théorie de l'esprit
15. Daigle, Christine - Brock University $42,873 Nietzsche as phenomenologist 16. Griffin, Nicholas J. - McMaster University$164,297
The collected letters of Bertrand Russell
17. Kumar, Rahul - Queen's University $51,300 Contractualism and the contours of morality 18. Russon, John E. - University of Guelph$27,445
Being through another: the idealist legacy in continental philosophy
19. Moggach, Douglas A. - University of Ottawa $53,832 Freedom and perfection: Kant's metaphysics of morals in context 20. Thompson, Evan T. - University of Toronto$41,640
The self and the brain: a neurophenomenological approach
21. Ripstein, Arthur S. - University of Toronto $71,050 Tort law as philosophy 22. Whiting, Jennifer E. - University of Toronto$58,000
Personal identity: practical yet metaphysical; or the ancient origins of Locke's account - and of any truly neo-Lockean account - of personal identity
23. Morrison, Margaret C. - University of Toronto $73,250 Computer simulation, modelling and experiment: knowledge at the boundaries 24. Mullin, Amy M. - University of Toronto$39,723
Children and parents: ethical relationships
25. Franks, Paul W. - University of Toronto $75,852 What is the human: Kantianism the development of the humanities and the threat of Nihilism 26. Nagel, Jennifer - University of Toronto$38,220
Metacognition and epistemic assessment
27. DeVidi, David M. - University of Waterloo $73,350 Pluralisms, mathematical and logical 28. Boran, Idil - York University$36,155
The idea of a market for carbon and its implications for philosophy and public policy
29. Shapiro, Lisa C. - Simon Fraser University $45,900 Emotions and sense perception in 17th and 18th century philosophy 30. Margolis, Eric - The University of British Columbia$64,250
The origins of human concepts
31. Aydede, Murat - The University of British Columbia $45,750 Pain and the nature of phenomenal consciousness 32. Woodcock, Scott - University of Victoria$46,108
Practical wisdom and naturalistic moral psychology

## Report on OpenProof Day 2009

Submitted by Richard Zach on Mon, 04/20/2009 - 5:50pm

[On March 27, 2009, Stanford/CSLI hosted a workshop on OpenProof (aka, the software behind Barwise and Etchemendy's Language, Proof, and Logic textbook). Alexei Angelides was there and provided the following report for LogBlog.]

On March 27th, CSLI and the OpenProof Project hosted a full day of presentation and discussion commemorating the, so to speak, tenth anniversary of the publication of Language, Proof, and Logic (LPL). I say "so to speak" because although the publication date was 1999, the date that appears on the first edition is 2000, a little tidbit of information that Etchemendy revealed was intentional, as both he and Barwise wanted its publication to symbolically coincide with the new millennium. The presentations were divided into six sections. Etchemendy began the day with a description of the history of the project; David Barker-Plummer followed with a description of the LPL package, including some of the new features that are going to be added to the next edition; this was followed by a roundtable discussion with three professors currently using the LPL courseware packages; then Richard Cox, one of the principal OpenProof researchers, presented some findings from data-mining the Grade Grinder corpus; Eric Pacuit, a modal logician currently at Stanford, presented on Kripke's World, a program intended to supplement work in modal logic; and, finally, Barker-Plummer ended the day with a description of OpenProof's main current research program, namely, HyperProof and OpenBox. I'll discuss a bit of the history, and some of the new features being added to LPL in the near future, and then describe just two of the presentations a bit. More info can be found here, including slides from each talk.

In the late '80s, Jon Barwise and John Etchemendy undertook work that attempted to blend different types of reasoning, primarily diagrammatic and sentential. Their work had two main aims, one theoretical, and the other pedagogical. On the theoretical side, Etch and Barwise were interested in challenging the "hegemony" of first-order predicate logic by arguing that reasoning with diagrams could be as rigorous as reasoning with a standard formal language. To this end, they developed so-called "heterogeneous" systems, formal systems that capture the structure of sentential or predicate reasoning (as in, e.g., sentential logic), and the structure of diagrammatic and visual reasoning (as in, e.g., reasoning with maps or Venn diagrams). On the pedagogical side, they were interested in using heterogeneous systems to enhance logic education, primarily at the college level, and so began to develop software packages that acted as supplements to the textbooks. By the mid-1990's, their work led to Hyperproof (1994) , a textbook and package of programs that implemented sentential reasoning alongside diagrammatic reasoning, making it possible to reason, say, with maps (or visual information more generally), and first-order sentences in the same contexts. Along with Tarski's World's first incarnation (1987), Turing's World (1986), and their The Language of First-Order Logic (1991), Hyperproof led to the first incarnation of LPL, a book that is nominally a course in first-order logic, but for which one of the programs allows students to evaluate the truth-values of sentences and the consequence relations between them, in a fully interpreted language called the "Blocks Language," by using the spatial and visual relationships between tetrahedra, cubes, and dodecahedra in the Tarski's World program.

Tarski's World is one of three programs designed to supplement a student's learning. The other two are Boole, a program designed to allow students to construct truth tables and test for truth-functionality and first-order consequence, and Fitch, a formal system for constructing proofs that includes the ability for teachers to allow and disallow certain rules to be used, and which includes a proof checker for students to verify their constructions. Of course, the software package also includes the Grade Grinder, which is like a very programmatic, 24-hour, mini-TA for students and instructors alike, giving some feedback to students who submit incorrect answers to it, and allowing teachers to relegate the more menial, possibly non-conceptual problems to the machine. (It includes, for students, the option of submitting solely to themselves in order to check if their answers are correct before submitting to the instructor.) Now, anyone who has used LPL knows how enormously helpful these programs are, both in terms of saving time for the professor using it, and pedagogically for the student, especially Tarski's World. Understanding how to abstract away from the meanings of the terms, and regard them as entirely uninterpreted has been, in my experience, the first road block for students. Tarski's World, though, acts as a kind of happy middle between the uninterpreted languages of first-order logic, and the interpreted kind we all grow up speaking.

However, anyone who has used LPL for anything more than an intro course also knows that software support drops off at chapter fifteen, the chapter in which we are introduced to first-order set theory, and after that, mathematical induction, and some of FOL's metatheory. In his presentation, Barker-Plummer noted that new editions of LPL rectify this. So, new editions enhance Fitch by adding the possibility of constructing inductive and set-theoretic proofs, the ability to "flag" lemmas, so that students do not have to reprove instances of, say, excluded middle, improved Henkin-Hintikka game play in Tarski's World, and a feature they're calling "goggles," in which the distinctions between tautological consequence, first-order consequence, and logical consequence are given a "visual" component. Thus, for example, if you're using your TautCon Goggles, only the sentential connectives are visible, and each instance of the same sentential letter gets assigned the same color, allowing the student to visualize the underlying logical structure of the argument. (Footnote: You might worry, as one audience member did, about how this might work for the (partially) colorblind or blind. An effective way to deal with this might be to have "goggled" areas shaded with variations in grey. For the blind, the problem is more general, obviously. For some recent work dealing with it see Jesse Alama, Patrick Girard, and Elizabeth Phillips's project on "brailling logic" here.) Finally, new editions of LPL will also include an ability for instructors to input their own exercises that are then gradable via the Grade Grinder, an addition, I think, that enhances the interaction between instructor and LPL, allowing instructors a bit more freedom in what they stress in their courses.

One of the most interesting presentations of the day was Cox's. Along with a few others (including Barker-Plummer), Cox has been data mining the results of the Grade Grinder in order to find the most common mistakes, and then attempting to give some explanation to those mistakes. Not only does this have interest in itself, since it's possible that such research leads to a better understanding of some of the cognitive processes underlying logical and, in at least one case as I'll explain in a second, visual reasoning. It also assists with updates to the LPL software, since by isolating the source of common errors in problem-solving, better feedback can be automatically generated by the Grade Grinder. They looked at two different exercises, one dealing with translations from English to FOL, and one dealing with the graphical interface between Tarski's World and the Blocks Language. For the first, the team selected an exercise of mid-range difficulty by looking at the number of submissions from beginning of data from the Grade Grinder (1999), rank ordering those submissions, and then choosing one with a high error rate, which turned out to be exercise 7.12 from chapter 7. (Footnote: Specifically, of 46,200 submissions, 27,473 were incorrect (59%), taken from a sample size of 4912 students, representing 5.6 incorrect sentences (out of 20).) Consider the following sentence:

• if a is a tetrahedron, then it is in front of d.

On this problem (7.12.1), students were in error 43%. But now consider:

• c is to the right of a, provided it (i.e., c) is small.

On this problem (7.12.4), students were in error 66%, reflecting the fact that when word order between natural language and first-order languages is not preserved in translation, the error rate rises. One frequent example that logic instructors everywhere will recognize immediately is the "only if" construction in English. As LPL points out, "only if" introduces a necessary condition. Even after much instruction, however, students are apt to translate "S only if P" as:

• P ? S.

Cox and his team found that, across all twenty sentences in problem 7.12, the frequency of error in translating from "only if" to FOL was 75.43%, a far higher error rate than any other conditional translation error. While many of their results dealing with translations from natural language into FOL are unsurprising, it is nice to see some statistics backing up anecdotal experience.

On the other hand, the third error the data miners canvassed was one dealing with the interface between Tarski's World and translations from natural language to FOL, this time with an unexpected result. Again choosing a problem of medium difficulty, 7.15, they found that one subproblem in particular, 7.15.7, suggested that students have a harder time with processing visual (sizes, etc.), as opposed to spatial (shapes, etc.) information. In the problem you are asked to start a sentence file in Tarski's World, and translate:

• d is a small dodecahedron unless a is small.

Note again the intuitively problematic conditional. Once the student has translated the sentence into FOL, she is asked to figure out the sizes and shapes of the objects named in all 12 subproblems. Then, the student is asked to build a world in Tarski's World where all of the sentences are jointly true. The point is that the student is asked to translate from English to FOL, then to determine, based on her translations, the relevant visual and spatial information, and then, based on her classification of that information, actually produce the required visual and spatial arrangement. In other words, the exercise takes the student from linguistic processing to visual and spatial processing. Cox and company found that for the above sentence, 92% of errors involved the size of d. But only 24% of errors involved its shape. (16% involved both.) So, given that such a high error rate was not found in cases involving translations between English and FOL that did not also involve the graphical interface, Cox suggested, based on research by Knauff (2001), that the information about an object's size may have negative effects on reasoning when it's not relevant to the problem. (Footnote: Of course, there are other interpretations of the data here, and Cox was careful to go through a few. I found this the most interesting for the purposes of making a distinction between linguistic, visual, and spatial types of reasoning. But see his slides (on the website) for more.)

Pacuit's presentation was on another new, but currently in progress, feature of the OpenProof project. Kripke's World, which the developers hope to have ready to accompany an as of yet unwritten text, is a means of evaluating modal formulae that is, in most respects, just like Tarski's World. Salient differences are that rather than using a propositional modal language, the developers have chosen a first-order modal language over the Blocks Language. Hence, upon opening Kripke's World, one is able to form sentences such as:

• ?? x Tet(x).

The states at which modal formulae are evaluated are Blocks Worlds. The interface is essentially the same as the Tarski's World interface, the difference being that multiple Blocks Worlds are constructible where there is an accessibility relation (reflexive, symmetric, Euclidean, and so on, selected from a useful drop down scroll list) between the various Kripke's Worlds that one constructs. So, for example, if one starts in a world where an object a is a cube, then in order for:

• ?Cube(a)

to be true, the object named by a must be a cube in all Kripke Worlds accessible from the initial world, reflecting the fact that names are rigid designators. Moreover, because the developers use a first-order modal logic, in Kripke's World objects have haecceity, a fact which is reflected in the software as well, as the "thisness" (represented in Kripke's World by Greek lettering) for an object in the initial world carries over to all subsequent worlds in which the formula containing it is evaluated. One feature, or problem--depending on who's looking--of their approach is that Kripke's World seems to be a nice approach for philosophers who are trying to emphasize the philosophical aspects of modal logic. But for logicians, who commonly emphasize the metatheoretic properties of modal logics, and its relation to (fragments of) first-order logic, it might not be as useful. For example, it doesn't touch on the myriad applications of modal logic, such as epistemic or deontic logic. Moreover, in my opinion another drawback of Kripke's World is that it uses the same graphical interface as Tarski's World. The salient difference is that more than one Tarski World is constructible, given an accessibility relation, but that only seems to visually complicate matters, whereas one of the nice things about Tarski's World is that, visually, it's so easy to use. Surely there's some happy middle, here. In any event, Pacuit brought up some very nice questions about Kripke's World, including one that has received much airtime at Stanford lately, namely, how best to integrate an introduction to modal logic within a standard course on first-order logic. Suffice it to say that this discussion is ongoing.

One final note on Barker-Plummer's final presentation, on OpenProof's OpenBox project. The OpenBox, a direct descendent of Barwise and Etchemendy's theoretical work that led to Hyperproof, is due to appear soon, and, as emerged from the discussion, is the most extant and up-to-date version of the original Hyperproof platform. As such, the intention is to integrate diagrammatic and sentential reasoning into a single software package. Now, however, the architecture of the program allows users to modify programs by plugging in "components," new interfaces that are uploaded by the users themselves, making the project entirely interactive. Hence, for example, an architect who wants to plan his next project might upload his design specifications, and then use the reasoning environment given by OpenBox to find his available possibilities, given his specifications. Or, as Etchemendy pointed out, one might use it to modify a picture, for example, in Adobe Photoshop, but use Openbox to save the history of all possibilities that had been available before a given modification to the picture. Of course, more theoretical uses are available, but the point of the components is to allow users to build their own reasoning specifications into different contexts, visual, spatial, sentential, and various combinations of the three. Barker-Plummer intends this to be a generalization of the notion of justification, and to the extent that it captures the reason for which an inference is made, whether in logical, architectural, or other contexts, this is correct. Indeed, it must be emphasized that maximal interaction between interface and user, and the systematic investigation of different types of reasoning, have been theoretical goals of the OpenProof Project since its inception, for it's led to a book, that led to a software and textbook package, that led to today's LPL, that led to OpenProof. So I hope, given their stress on interaction and the commemoration's fruitfulness, that more meetings like this take place.

## Choice & Inference: New Group Blog

Submitted by Richard Zach on Thu, 04/16/2009 - 2:58pm

Jake Chandler at Leuven's Centre for Logic and Analytic Philosophy, and Jonah Schupbach, currently at Tilburg's Center for Logic and Philosophy of Science, have started a new group blog, Choice & Inference:

Welcome to the new group blog, Choice & Inference! This blog provides a platform for dialogue and news within the fields of formal epistemology and decision theory, broadly construed. Topics include (but are not limited to) uncertain and ampliative inference, coherence, paradoxes of belief and / or action, belief revision, disagreement and consensus, causal discovery, epistemology of religion, etc. And the formal tools used to pursue questions within these topics include (but are not limited to) game theory and decision theory, formal learning theory, probability theory and statistics, networks and graphs, and formal logic.

## Awodey on Sets, Types, Categories and the Foundations of Mathematics

Submitted by Richard Zach on Thu, 04/16/2009 - 5:59am

There are a number of foundational schemes out there. ZFC set theory is perhaps the most widely known, but of course you can also develop math in type theory. And you can also do it in category theory. So what's the difference? Steve Awodey has an answer in a preprint of a paper, now posted on his web site: "From Sets to Types to Categories to Sets". Here's the introductory paragraphs:

Three different styles of foundations of mathematics are now commonplace: set theory, type theory, and category theory. How do they relate, and how do they differ? What advantages and disadvantages does each one have over the others? We pursue these questions by considering interpretations of each system into the others and examining the preservation and loss of mathematical content thereby.

In order to stay focused on the “big picture”, we merely sketch the overall form of each construction, referring to the literature for details. Each of the three steps considered below is based on more recent logical research than the preceding one. The first step from sets to types is essentially the familiar idea of set theoretic semantics for a syntactic system, i.e. giving a model; we take a brief glance at this step from the current point of view, mainly just to fix ideas and notation. The second step from types to categories is known to categorical logicians as the construction of a “syntactic category”; we give some specifics for the benefit of the reader who is not familiar with it. The third step from categories to sets is based on quite recent work, but captures in a precise way an intuition from the early days of foundational studies.

With these pieces in place, we can then draw some conclusions regarding the differences between the three schemes, and their relative merits. In particular, it is possible to state more precisely why the methods of category theory are more appropriate to philosophical structuralism.

UPDATE: Peter Smith had the good judgment of also quoting from the conclusion, where Steve makes the point that the advantage of the category-theoretic approach is that, of the three approaches, category theory is the system that allows formalization of only the structurally invariant mathematical facts, those that don't depend on specific features of the foundational scheme (say, where in the cumulative hierarchy something lives)--although you can have all that extra structure in the category-theoretic setting, if you want or need it.

## Travel grants for Women in Computability at CiE 2009

Submitted by Richard Zach on Thu, 04/16/2009 - 4:12am

This call for applications for Elsevier Foundation Travel Grants for junior female researchers for the CiE 2009 conference just came over the wire:

We are offering up to five travel grants for junior female researchers to come to CiE 2009. These grants cover the registration fee (at the early rate) plus a travel reimbursement of up to 300 EUR (after you submit original receipts).

In order to be considered for this grant, please send an e-mail to Elvira Mayordomo at: elvira@unizar.es

with the following information: a brief motivation, a short CV (at most two pages), and contact information for an academic reference. Preference will be given to applicants who present a paper (including informal presentations) - for instructions on how to submit an informal presentation, see:

http://www.math.uni-heidelberg.de/logic/cie2009/pb_informalpres.php

Please submit your Travel Grant application before 1 May 2009. Decisions will be communicated in mid May.

## Logical Positiv-its

Submitted by Richard Zach on Wed, 04/01/2009 - 5:39am

My colleague Marc Ereshefsky brought me back a book of sticky notes from LA: Logical Positivi-its. There are three: a defintional double arrow, one with a picture of Otto Neurath, and one with a picture of Wittgenstein with three check boxes: tautology, meaningless, or Schweigen (be silent).

## ESSLLI 2009 in Bordeaux

Submitted by Richard Zach on Wed, 04/01/2009 - 5:21am

If you'd rather go to France than Pittsburgh or LA, or you're not an undergrad student:

21st EUROPEAN SUMMER SCHOOL IN LOGIC, LANGUAGE AND INFORMATION

Bordeaux, July 20-31 2009

The European Summer School in Logic, Language and Information (ESSLLI) is organized every year by the Association for Logic, Language and Information (FoLLI) in different sites around Europe. The main focus of ESSLLI is on the interface between linguistics, logic and computation.

The 21st edition of ESSLLI will be held in Bordeaux, recently selected as a Unesco World Heritage site.

ESSLLI gathers about 500 people and offers a total of 48 courses and workshops, divided among foundational, introductory and advanced courses, and including a total of 6 workshops. The courses and workshops cover a wide variety of topics within the three areas of interest: Language and
Computation, Language and Logic, and Logic and Computation.

Registration for ESSLLI is open. Early registration rates are 225 euros for students and 350 euros for others.

Early registration deadline: 1st of May 2009.

There is a limited number of fee waivers available for students who want
to spend some time assisting the organizing committee during ESSLLI.

## Antonelli, Belnap, Segerberg in Calgary this Weekend

Submitted by Richard Zach on Tue, 03/24/2009 - 11:13pm

We're having a little logic conference this weekend in Calgary. If you're in the area, please come! All talks in 1253 Social Sciences, University of Calgary. Relevant papers may be found by following the links below

## Nuel Belnap (Pittsburgh)

Friday, March 27, 4 pm

### Truth Values, Neither-True-Nor-False, and Supervaluations

My oral remarks are based on an essay to appear in Studia Logica. (The essay evidently has more sections that I can adequately treat in the time allotted.) The first section defends reliance on truth values against those who, on nominalistic grounds, would uniformly substitute a truth predicate. I rehearse with great brevity some practical, Carnapian advantages of working with truth values in logic. In the second section, after introducing the key idea of "auxiliary parameters," I look at several cases in which logics involve, as part of their semantics, an extra auxiliary parameter to which truth is relativized, a parameter that caters to special kinds of sentences. In many cases, this facility is said to produce truth values for sentences that on the face of it seem neither true nor false. Often enough, in this situation appeal is made to the method of supervaluations, which operate by "quantifying out" auxiliary parameters, and thereby produce something like a truth value. Logics of this kind exhibit striking differences. I first consider the role that Tarski gives to supervaluation in first order logic, and then, after an interlude that asks whether neither-true-nor-false is itself a truth value. I consider sentences with non-denoting terms, vague sentences, ambiguous sentences, paradoxical sentences, and future-tensed sentences in indeterministic tense logic, I conclude my survey with a look at alethic modal logic considered as a cousin, and finish with a little "advice to supervaluationists," advice that is largely negative. The case for supervaluations as a road to truth is strong only when the auxiliary parameter that is "quantified out" is in fact irrelevant to the sentences of interest--as in Tarski's definition of 'truth' for classical logic. In all other cases, the best policy when reporting the results of supervaluation is to use only explicit phrases such as "settled true" or "determinately true," never dropping the qualification.

http://www.phil.ucalgary.ca/philosophy/node/410

## Krister Segerberg (Uppsala/Calgary)

Saturday, March 28, 10 am

I am trying to develop a dynamic deontic logic, the outlines of which I will sketch. To motivate this attempt, and also to assess its merits, I will consider three classic paradoxes: those due to Chisholm, Ross, and Forrester.

## Aldo Antonelli (Davis)

Saturday, March 28, 2 pm

### Free Quantification and Logical Invariance

In order to present the problem of providing a natural and well-behaved semantics for (positive) free logic, a number of approaches are considered, some old, some new -- all of which are found wanting in some respect or other. We then shift our perspective in order to tackle the problem from the standpoint of the theory of generalized quantifiers, with accompanying emphasis on permutation invariance as a characteristic feature of logical notions. This will finally result in a natural and well-motivated semantic theory for positive free logic -- which, however, also leads to questioning the logical nature of free quantification.

http://www.phil.ucalgary.ca/philosophy/node/493

## Who's The Most Famous Philosopher of the 20th Century?

Submitted by Richard Zach on Tue, 03/03/2009 - 1:56am

On Leiter's blog there was a poll on the question "who's the most important philosopher of the 20th century", prompted by the unqualified assertion by Jim Holt in a NYT book review that that would be Wittgenstein. The results were widely debated, e.g., on Crooked Timber. The reason the results were contentious, I think, is because the methodology was severely flawed and consequently the results were widely off. Of course the proper methodology would be to find a property that correlates with the property you're interested in, but that is objectively measurable. Obviously, the property you should be interested in here is fame. Below a ranking of the philosophers included in Leiter's list, sorted by fame (measured in dBHa, the international logarithmic unit of fame, see Schulman 2009).

 Rank Name Rank Leiter Rank dBHa 1 Bertrand Russell 1 2 -1.9 2 Jean-Paul Sartre 2 10 -2.25 3 Michel Foucault 3 7 -2.75 4 Jürgen Habermas 4 20 -2.89 5 John Dewey 5 11 -3.83 6 Simone de Beauvoir -3.98 7 Martin Heidegger 6 4 -4.01 8 Hannah Arendt -4.26 9 Ludwig Wittgenstein 7 1 -6.29 10 Iris Murdoch -6.9 11 Richard Rorty 8 22 -6.96 12 Gilles Deleuze 9 21 -7.28 13 Karl Popper 10 8 -7.44 14 Theodor Adorno 11 16 -7.91 15 Hans-Georg Gadamer 12 27 -8.03 16 Henri Bergson 13 24 -8.28 17 John Rawls 14 5 -8.75 18 Judith Butler -9.43 19 Maurice Merleau-Ponty 15 23 -9.48 20 Alfred North Whitehead 16 26 -9.84 21 Julia Kristeva -10.37 22 Bernard Williams 17 12 -10.38 23 Donald Davidson 18 17 -10.62 24 Ernst Cassirer 19 27 -10.69 25 Hilary Putnam 20 18 -10.78 26 Luce Irigaray -11.21 27 G. E. Moore 21 15 -12.02 28 W. V. O. Quine 22 6 -12.83 29 Martha Nussbaum -14.29 30 Rudolf Carnap 23 13 -14.65 31 Donna Haraway -14.95 32 Elizabeth Anscombe -15.3 33 P. F. Strawson 24 24 -17.08 34 Alfred Tarski 25 18 -17.14 35 C.I. Lewis 26 29 -17.88 36 Saul Kripke 27 9 -18.46 37 Michael Dummett 28 30 -18.52 38 Wilfrid Sellars 29 14 -18.79 39 Susan Haack -21.89 40 Philippa Foot -22.04 41 David K. Lewis 30 3 -23.06

The top 8 are B-list celebrities, 9-31 are C-list, by Schulman's standard.

UPDATE: Prompted by Rob Wilson's comment, I added a number of women philosophers to Leiter's original list.

References

Schulman, E. 2009, "Measuring Fame Quantitatively. IV. Who's the Most Famous of Them All?" Annals of Improbable Research Online, February 28. (see also AIR February 28)

## Beth Dissertation Prize Call for Nominations

Submitted by Richard Zach on Sat, 02/28/2009 - 7:19pm

FOLLI is soliciting nominations for the 2009 Beth Dissertation Prize in Logic, Language, and Information.

Since 2002, FoLLI (the European Association for Logic, Language, and Information, www.folli.org) awards the E. W. Beth Dissertation Prize to outstanding dissertations in the fields of Logic, Language, and Information. We invite submissions for the best dissertation which resulted in a Ph.D. degree in the year 2008. The dissertations will be judged on technical depth and strength, originality, and impact made in at least two of the three fields of Logic, Language, and Computation. Inter-disciplinarity is an important feature of the theses competing for the E. W. Beth Dissertation Prize.