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Possibly the Best xkcd Ever

Submitted by Richard Zach on Sat, 11/26/2011 - 4:02pm

Proof of Zermelo's well-ordering theorem given the Axiom of Choice: 1: Take S to be any set. 2: When I reach step three, if S hasn't managed to find a well-ordering relation for itself, I'll feed it into this wood chipper. 3: Hey, look, S is well-ordered.

Follow link for the mouseover text!

New Linguistics Entries in SEP

Submitted by Richard Zach on Sat, 11/26/2011 - 3:59pm

Two interesting new entries in the Stanford Encyclopedia:

CfP: Mind, Language and Cognition: Historical Perspectives.

Submitted by Richard Zach on Tue, 11/15/2011 - 4:15pm

The first annual conference of the Society for the Study of the History of Analytical Philosophy will be held at McMaster University, Hamilton (Canada) 24-26 May 2012.

Invited Speakers

Michael Friedman (Stanford University)
Paolo Mancosu (University of California, Berkeley)
Thomas Uebel (University of Manchester)

Canadian Student Presenters Travel Bursaries

SSHAP will be offering up to 10 travel bursaries to Canadian student presenters. The bursaries will cover transportation to as well as accommodation and subsistence in Hamilton. Bursaries will be awarded on the basis of need and scientific merit.

Call for Papers

SSHAP invites submissions for its 2012 annual conference. Paper submissions in all areas of the history of analytic philosophy are welcome. A selection of papers from the conference will be published in a special volume of the Journal for the History of Analytical Philosophy.

SUBMISSION DEADLINE: November 30th, 2011.

Submission Instructions

Authors are requested to submit their papers electronically according to the following guidelines:

1) Papers should be prepared for blind refereeing, 2) put into PDF file format, and 3) sent as an email attachment to the address given below -- where 4) the subject line of the submission email should include the key-phrase "SSHAP submission", and 5) the body text of the email message should constitute a cover page for the submission by including i) return email address, ii) author's name, iii) affiliation, iv) paper title, and v) short abstract.

Time allowed for presentation is 60 minutes (including discussion). We recommend that paper be no longer than 4000 words.

Electronic submissions should be sent to:

For more information, please visit our website

Postdoc in Proof Theory in Vienna

Submitted by Richard Zach on Sun, 11/13/2011 - 10:45am

The Vienna University of Technology is looking to recruit one Postdoctoral Research Assistant to work on the FWF-funded project "Nonclassical Proofs: theory, applications and tools", under the direction of Agata Ciabattoni.

The work will take place within the Institute of Computer Languages (Theory and Logic group) of the Vienna University of Technology. The post is for an appointment of up to 24 months and is available from January 2012.

Applicants should have (or shortly expect to receive) a PhD in Mathematics, Computer Science or a closely related field, a strong background in structural proof theory, nonclassical logics, and, preferably, knowledge of universal algebra or complexity theory. Ability to work independently but also with academic colleagues and PhD students, flexibility and teamwork, are all important qualifications for this position.

Further particulars, including details of how to apply, are available from: Potential applicants are also welcome to send informal inquiries to Agata Ciabattoni ( The closing date for applications is Thursday, December 1st 2011.

Four Experimental Studies on Vagueness

Submitted by Richard Zach on Sat, 11/12/2011 - 2:32pm

Phil Serchuk's paper (with Ian Hargreaves and me) describing some experimental philosophy of logic he did when he was writing his undergrad thesis with me back in '05 is now out in Mind and Language.  It's a response to a 1999 paper by Tim Williamson together with psychologists Bonini, Osherson, and Viale, and we also have something to say about Brian Weatherson's "True, Truer, Truest" paper.

Although arguments for and against competing theories of vagueness often appeal to claims about the use of vague predicates by ordinary speakers, such claims are rarely tested. An exception is Bonini et al. (1999), who report empirical results on the use of vague predicates by Italian speakers, and take the results to count in favor of epistemicism. Yet several methodological difficulties mar their experiments; we outline these problems and devise revised experiments that do not show the same results. We then describe three additional empirical studies that investigate further claims in the literature on vagueness: the hypothesis that speakers confuse ‘P’ with ‘definitely P’, the relative persuasiveness of different formulations of the inductive premise of the Sorites, and the interaction of vague predicates with three different forms of negation.

If you don't have access, I will gladly send you an electronic offprint -- just email me. 

Creath on Logical Empiricism in the SEP

Submitted by Richard Zach on Sat, 04/16/2011 - 9:21pm

My "boss" on the Carnap Edition project, Richard Creath, has a new entry on Logical Empiricism for the Stanford Encyclopedia.

E. E. C. Jones in the SEP

Submitted by Richard Zach on Sat, 03/26/2011 - 6:25pm

Everyone should read this new entry in the SEP

Emily Elizabeth Constance Jones (1848–1922), a contemporary of Bertrand Russell and G. E. Moore at Cambridge University, worked primarily in philosophical logic and ethics. Her most significant contribution to the former area is her application of the intension-extension distinction to singular terms, anticipating Frege's related distinction between sense and reference and Russell's pre-“On Denoting” distinction between meaning and denotation. Widely regarded as an authority on philosophical logic by figures as diverse as F. C. S. Schiller and G. F. Stout on the one hand and C. S. Pierce on the other … Russell delivered a paper to the Moral Sciences Club, subsequently published as “Knowledge by Acquaintance and Knowledge by Description”, responding to a critical paper by Jones, delivered to the same society some months earlier. Jones also published in ethics, and was regarded by Henry Sidgwick, her mentor, as one of his prize students. Yet, despite the fact that she published numerous articles, a monograph and several textbooks (some going into multiple editions), and was a very visible member of the English philosophical community from the 1890s until her death in 1922, she is now almost entirely forgotten.

Next time I'm teaching history of analytic philosophy, I'll assign Jones (and Stebbing).  Not sure why I didn't do it this year: I did assign Russell's "Knowledge by acquaintance" after all!

Jones was not the only woman contributing to philosophical logic and related areas at the beginning of the twentieth century: Pierce's student, Christine Ladd-Franklin (1847-1930) made significant contributions to logic and psychology, and the writings of Lady Victoria Welby (1837–1912) on meaning were widely read. … Later figures include the philosopher of science, Dorothy Wrinch (1894–1976), a Girton student who went on to study under Russell, and Susanne Langer (1895–1985), who wrote a dissertation under Alfred North Whitehead at Radcliff in 1926. Wrinch, who published papers in Mind on, among other things, the theory of relativity, later abandoned philosophy for chemistry, teaching for many years at Smith College. Langer, who later achieved prominence in the philosophy of art, published several technical articles on type theory and related topics early in her career (see, for example, Langer 1926, 1927). Possibly the most prominent woman analytic philosopher of the first half of the twentieth century, however, was another Girton student, L. Susan Stebbing (1885–1943), Professor of Philosophy at Bedford College, London, and co-founder of the journal Analysis.

Postdoc in Logic/Philosophy of Science at Calgary

Submitted by Richard Zach on Fri, 03/18/2011 - 2:17pm

The Department of Philosophy at the University of Calgary invites applications for a one-year postdoctoral fellowship starting on September 1, 2011. The area of specialization is logic or the philosophy of science. The fellow will be expected to have a well-defined research project, teach one course in the area of specialization, and participate in the research activities of the Department. All requirements for the PhD must have been completed by the starting date and no earlier than September 2007. The stipend is $50,000 Canadian per year.

Specific inquiries about this position may be directed to:

Ali Kazmi, Head
Department of Philosophy
University of Calgary

Complete dossiers, including a cv, at least three letters of reference, postgraduate transcripts, a recent sample of writing, and a detailed research proposal may be sent to:

Merlette Schnell, Manager
Department of Philosophy
University of Calgary
2500 University Drive NW
Calgary, Alberta T2N 1N4

Applications will be accepted until April 15, 2011 or until the position is filled.

25 years of AGM

Submitted by Richard Zach on Tue, 03/15/2011 - 3:46pm

The AGM Theory of Belief Revision was 25 years old last year, and the JPL has a special anniversary issue on it.

Hilary Putnam Awarded 2011 Schock Prize in Logic and Philosophy

Submitted by Richard Zach on Mon, 03/14/2011 - 10:47am

The Swedish Academy awarded the 2011 Rolf Schock Prize to Hilary Putnam "for his contribution to the understanding of semantics for theoretical and ‘natural kind’ terms, and of the implications of this semantics for philosophy, theory of knowledge, philosophy of science and metaphysics".

Here's the citation:

Hilary Putnam is one of the most versatile philosophers of our time. He has written more than 20 books and more than 300 articles, on subjects ranging from mathematical logic to religion.

The work that is being rewarded with the 2011 Rolf Schock Prize in Logic and Philosophy belongs to the interface between philosophy of language, philosophy of science and metaphysics. In particular, it concerns the semantics for two sorts of linguistic expressions: theoretical terms in science, like ‘atom’ and ‘energy’, and everyday words for ‘natural kinds’, like ‘gold’ and ‘water’.

The starting point is Willard Van Orman Quine’s critique of the distinction between analytic and synthetic propositions. The former are said to be true by virtue of their meaning, while the truth of the latter also depends on the world. Thus, ‘all bachelors ride bicycles’ is synthetic, while ‘all bachelors are unmarried’ is analytic.

Unlike Quine, Putnam held fast to this example of analyticity: anyone who denies the proposition must be using one of the words to mean something other than we do. But for theoretical terms, no clear-cut distinction is possible. These terms are associated with clusters of natural laws. If we reject all statements of laws concerning energy, we have undoubtedly changed the meaning of the term ‘energy’; but for a change to take place it is unclear which, or how many, statements we must reject.

Accordingly, the meaning of theoretical terms can be preserved when a theory is modified. This revision of semantics makes, in turn, scientific realism possible: the new theory deals with the same phenomena as the old one.

Putnam subsequently combined these views with meaning externalism. The meaning of ‘natural kind’ terms, such as ‘water’, is determined by language users’ surroundings and not by the stereotypical characteristics they associate with the term, such as quenching thirst and flowing in rivers. On another planet outwardly just like ours, and perceived as such by its inhabitants, a substance other than H2O – XYZ, say – could have these characteristics instead. For speakers on this Twin Earth, ‘water’ would mean ‘XYZ’, while we should truthfully deny that there is any water on their planet. The conclusion is that ‘meanings just ain’t in the head’.

Hilary Whitehall Putnam was born in Chicago in 1926. After studies at the University of Pennsylvania and Harvard University, he received his PhD in 1951 from the University of California, Los Angeles, with Hans Reichenbach and Rudolf Carnap as his supervisors. In 1965, after a long residence at the Massachusetts Institute of Technology (MIT), he moved to Harvard where, in 1976, he was appointed as Walter Beverly Pearson Professor of Mathematical Logic. Today, he is Cogan University Professor Emeritus at Harvard University.

Putnam is a past President of the American Philosophical Association (Eastern Division), the Philosophy of Science Association and the Association for Symbolic Logic. He is a Fellow of the American Academy of Arts and Sciences, and a Corresponding Fellow of the British Academy (the UK’s national academy for the humanities and social sciences) and the French Académie de Sciences Morales et Politiques. He is married to Ruth Anna Putnam.

The prize for visual arts goes to Marlene Dumas. The prizes for Music and Mathematics will be annoucned on March 21.

PhD Fellowships in Mathematical Philosophy in Munich

Submitted by Richard Zach on Thu, 03/10/2011 - 9:21am

From Hannes Leitgeb's new Center for Mathematical Philosophy at the LMU Munich:

Four doctoral fellowships are being advertised at the Munich Center for
Mathematical Philosophy (MCMP). The MCMP, which is devoted to
applications of logical and mathematical methods in philosophy, has
recently been established at the Ludwig-Maximilians-University Munich
(LMU) based on generous support by the Alexander von Humboldt
Foundation. Directed by Professor Hannes Leitgeb, the Center hosts a
vibrant research community of university faculty, postdoctoral fellows,
doctoral fellows, and visiting fellows.

Details here .

LogBlog Move

Submitted by Richard Zach on Wed, 03/09/2011 - 10:10pm

LogBlog moved last year. I've tried to make it noticeable as little as possible--the RSS feed has been redirected for a while. So even if your feed reader is set to you stil get the new posts.  But you should really change it!  (to

And now I've also put in redirects from all the old pages, so no more finding an old LogBlog post and landing on a version where you can't comment.  If you do find one, please let me know!

Venn Diagrams

Submitted by Richard Zach on Sat, 03/05/2011 - 1:59pm

Funny Venn diagrams, a vaguely-logic-related internet thing:

Not sure where that last one originated.  Any other good suggestions?

Representation of Women in Philosophy, Again

Submitted by Richard Zach on Wed, 02/16/2011 - 11:50am

Since Leiter just quoted data on women in philosophy faculty positions collected by Kathryn Norlock, and over at Feminist Philosophers someone asked for a breakdown by tenure status, here it is. This is survey data from 2003 (the same dataset from which the figures Leiter quotes come) which means there is sampling error. The first (grey) line gives the percentages for each category of the total, the second line gives the percentage of women per category (i.e., 6.3% of all surveyed philosophy faculty are tenured women; of the tenured philosophy faculty surveyed, 17.1% are women). You can make your own tables here.  See also previous discussion and comparison with other fields and data on the pipeline here and here

The problem is that the standard errors in the survey results are really high. We talked about this in the previous post, noting that this data isn't very reliable.  The data was compiled from a survey of approx 18,000 faculty, of which 1.9% were philosophers. So it's based on a sample of about 350 out of a total of approx. 23,000 philosophy faculty (full and part time) overall in 2003. In the case of these figures in particular, what the survey tells us is only that the percentage of women among tenured philosophy faculty is somewhere between 8.5% and 25.6% (at 95% confidence). (Edited, thanks to Jingjing Wu for help with the stats.)

Tenure status and gender Tenured, male
Tenured, female
On tenure track, male
On tenure track, female
Not on tenure track, male
Not on tenure track, female
Total 19.3 8.7 7.1 5.1 31.1 28.7 100%
  per category   31.0    41.8    47.9  42.5
Philosophy 30.5 6.3 10.5 1.5 39.0 12.3 100%
  per category   17.1    12.5    23.9  21.0
Standard Errors
Total 0.30 0.19 0.20 0.15 0.30 0.22  
Philosophy 3.15 1.80 2.04 0.67 4.78 2.73  
Weighted Sample Sizes (n/1,000s)
Total 1211.85            
Philosophy 13.19            
NOTE: Rows may not add up to 100% due to rounding.
SOURCE: U.S. Department of Education, National Center for Education Statistics, 2004 National Study of Postsecondary Faculty (NSOPF:04).
Computation by NCES QuickStats on 2/16/2011

NB: I've switched blogging software. If you click a link and land on a page and wonder why you can't comment, take the url, e.g., and replace 'people' by 'www' and 'logblog' by 'blog' to get to the current version like so:

Visual Representation of Philosophers' Significance and Influence

Submitted by Richard Zach on Wed, 02/09/2011 - 8:22pm

My colleagues Marian Dörk and Sheelagh Carpendale over in the Computer Science department have taken data on philosophers from Freebase as a test case for their EdgeMaps visualization project.

Freebase provides data about interests, professions, birthdates, influence connections, and other relations from Wikipedia. For the purpose of this paper, we have constrained the dataset to philosophers that influenced at least one other philosopher, resulting in 42 philosophers. For each philosopher we store the name, birthdate, description, an image, interests, and professions. Furthermore, we store the directed influence links between philosophers.

Go to the EdgeMaps page, click on the "open demo" button, and explore. The button in the top left switches between a timeline view and an influence "yarnball".Of course, the map is only as good as the data that went in--see the example of Frege below which is missing a big fat influence arrow coming from Kant!--but still, very cool!

EdgeMap of Frege

SEP Entry on the Liar Paradox

Submitted by Richard Zach on Fri, 02/04/2011 - 1:22pm

Logic in the Undergraduate Mathematics Curriculum

Submitted by Richard Zach on Fri, 02/04/2011 - 11:39am

As part of the work of the Committee on Logic Education of the Association of Symbolic Logic, Marcia Groszek and Tamara Lakins organized a special session on logic in the undergraduate mathematics curriculum at the Joint Mathematics Meeting last month in New Orleans.  The session was very successful: excellent talks, good turnout.  The talks were:

  • Breadth, Depth, Disputes, Drama, and Campus Pranks:  The Possibilities and Pleasures of Co-teaching Logic, by James M. Henle
  • A Course Emphasizing Mathematical Logic and Reasoning that is Appropriate for General Education and Elementary Education Majors, by Warren W. Esty
  • Seemingly Abstruse Logical Principles Have Practical Importance, by Susanna S. Epp
  • Applied Logic Courses in the Mathematics Curriculum, by Lawrence S. Moss
  • Technology in Logic Education:  Courseware, Automated Assessment and Data Minin, by Dave Barker-Plummer

You can find abstracts and links to the presentation materials on the ASL CLE's page on the special session.

Begging the Question

Submitted by Richard Zach on Wed, 02/02/2011 - 1:13pm

Just happened upon this LanguageLog post on "begging the question" from last year.  Very interesting!

Gregory Hjorth, 1963-2011

Submitted by Richard Zach on Fri, 01/28/2011 - 12:55pm

Greg Hjorth died unexpectedly on January 13. He was 47.  Greg received his degree from UC Berkeley under the supervision of Hugh Wooding in 1993.  He held positions at Caltech, UCLA, and the University of Melbourne.  Together with Alexander Kechris, he recieved the ASL's Karp Prize in 2003. Last year, he was chosen as Tarski Lecturer at Berekely.  He was also an outstanding chess player, and awarded the title International Master in 1984.

There is a memorial group on facebook, and one at the Australian.  Greg and Herb Enderton will be honored at the upcoming Very Informal Gathering of logicians at UCLA, February 4. Some pictures and tributes are collected here.

Here's the abituary from the front page of the UCLA Math Department:

Professor Greg Hjorth died of a heart attack in his birth city of Melbourne, Australia, on Jan. 13. He was 47. Hjorth was recognized as a young chess whiz in his primary school years. He quickly advanced to tournament chess, becoming joint Commonwealth Champion in 1983 and earning his International Master title in 1984. He played Garry Kasparov, among other accomplished chess rivals, but took his own later advice that "if you're not in the top 100 by 21, get out." Hjorth's passion for chess played over to mathematical logic, a field that saw him reach great heights with high academic honors and wide recognition. After receiving his undergraduate degree in mathematics and philosophy at the University of Melbourne, Hjorth continued his studies at UC Berkeley, where he received his PhD in mathematics under the supervision of Hugh Woodin in 1993. As a graduate student, Hjorth was recognized for his exceptional talent, and his brilliant thesis was awarded the first Sacks Prize in 1994 by the Association for Symbolic Logic for his research in descriptive set theory and its surprising consequences concerning the relationship between projective sets and large cardinals. Hjorth pursued his postdoctoral studies at Caltech for two years then joined the mathematics faculty at UCLA in 1995, where he was made full professor in 2001. Since 2006, he spent two quarters of each year at the University of Melbourne appointed to a prestigious Australian Research Council professorial fellowship.

Over his 16 years at UCLA, Hjorth has been acknowledged as a world leader in the field of mathematical logic and its applications to other fields of mathematics. He has made a series of stunning and far reaching contributions, in particular to ergodic theory and orbit equivalence of group actions. These included the development of entirely new theories, including what is now called Hjorth's theory of turbulence, which has had a major impact in contemporary work in set theory and its applications. Hjorth was known as a brilliant problem solver, having been able to achieve major breakthroughs in problems that were previously considered in tractable, including his remarkable work on the famous topological Vaught Conjec ture and most recently, his results on the incomparability of treeable equivalence relations. His work consistently amazed his colleagues with its uncanny originality and technical wizardry and has been recognized by many honors, including a Sloan Foundation Fellowship in 1997, an invited lecture at the International Congress of Mathematicians in 1998, the ASL Karp Prize in 2003 (joint with Alexander Kechris), and last year, an invitation to deliver one of the major lecture series in logic, the Alfred Tarski Lectures at UC Berkeley. Hjorth supervised eight PhD students at UCLA, including 2008 UCLA Math PhD Inessa Epstein, who also received the prestigious Sacks prize.

Hjorth will be richly remembered by fellow colleagues as a brilliant mathematician in constant pursuit of solutions to intractable problems, and as a committed and caring teacher. He is survived by his parents Noela and Robert, and his sister Larissa. In honor of Hjorth, the UCLA Logic Center is hosting a special lecture by Alexander Kechris on Hjorth’s work to be held Friday, February 4 at 2:30pm in Young Hall, CS24. The in memoriam will begin at 2:00pm.