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July 30, 2005

Conference Blogging

Greg Restall has been blogging the 2005 Logic Colloquium in Athens. Before he left, Greg and I had a chat about value of conference blogging. We agreed that it can be very good, but Greg had worries about etiquette. How critical is it polite to be? Or politic to be? Could failing to mention someone's talk be taken to be tacitly critical? Or does everyone understand that the author of the post has not undertaken to present a balanced account of the entire conference, but just a few notes on a couple of things that interested them?

This topic might seem silly and self-aggrandising. It would be arrogant to overestimate the extent to which one's blog is read, of course, and the weight given to what one says. But then, it would be foolish to underestimate the accessibility of information on the web; no-one would be very happy about the number one search result for their name being an off-the-cuff criticism of their paper by some lazy blogger who didn't understand it properly. (Or even a blogger who did.)

This is just a subgenre of a topic that Brian - seminal, and very widely-read blogger that he is (my lawyers asked me to add that phrase) - has worried about from time to time: the ethics of blogging. I think the factors which combine to make it tricky are the natural informality and immediacy of the medium, along with the accessibility and longevity of items on the web. It's easy to assume that one's core (and comment-happy) audience is one's entire audience, (hello fellow logic bloggers!) but of course in principle it can include one's students, senior colleagues, rivals, family, journalists, philosophical opponents, MI6, JK Rowling (it's so easy to forget she has internet access) and other celebrities, including those in one's own profession, whom one will undoubtedly run into in the queue for coffee at a conference next month.

A friend once told me that his mother had instructed him never to write anything in an email that he would not write on a postcard. But the average blog is much more public and widely-read than the average postcard (even if we include the postcards which I write to my gran in Winchburgh, which get read by the local postman before he delivers them. "Oh hello Mrs Russell, I see your granddaughter still hasn't settled down ...") Could we come up with a similar rule-of-thumb for blogging? Perhaps one way to do it would be to consider the extreme cases: don't write anything in your blog which you wouldn't want to be read by i) the members of a hiring committee, ii) your students, iii) your father.

On a completely unrelated note, things will be quiet around here for a while. I'm back off to the UK on Monday and they tell me it's half a world away...

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July 28, 2005

How to read philosophy in Melbourne...


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July 26, 2005

Adventures in Flatland

I have been reading Lloyd Humberstone's 2D modal logic retrospective, "Two Dimensional Adventures," (Philosophical Studies 118 (March 2004) 17-65) in the hope that it might help me with a problem in a paper I'm writing. I thought I would write up some notes about it here.

Interesting thing number one: Humberstone distinguishes the sense of "two-dimensional" with which his paper is concerned from a thousand other senses with which that expression is used. Did you know that Max gives a logic of two dimensional formulas? (As in "formulas constructed out of columns of ordinary formulas joined by connectives") or that Pratt refers to ordinary modal logics as two dimensional?

The kind of two dimensional logic we (Professor Humberstone, me, and you, gentle reader) are interested in is a semantics which treats the truth of a formula as relativised to elements of the set U0 × U1 (i.e. as relative to an ordered pair of say, a time and a place, or a possible world and...another possible world.) Humberstone goes on to distinguish two kinds of 2D semantics in this sense. A 2D semantics is homogenous if U0= U1, heterogenous where U0≠ U1. A semantics within which the truth of a formula is relativised to say a time and a possible world would be 2D in our sense, only heterogenously so, whereas Humberstone intends to restrict his study to homogenous cases and observes that "the clauses we offer for various operators in the definition of truth (w.r.t. a pair of points in a model) would not make sense without this assumption of homogeneity, since they involve things like moving the occupant of sone of the two coordinates into the position occupied by the other."

I thought it was interesting that Humberstone's conception of a two dimensional modal logic comes apart from David Kaplan's even at this early stage. Kaplan's formulas are true with respect to pairs of circumstances of evaluation (possible worlds) and contexts of utterance (ordered quadruples of agent, time, location and world) and the conceptual difference between the two is an important part of his theory.

Humberstone ends the section with a joke:

This distinction between homogeneous and hetergeneous cases of two-dimensionality arises at the level of informal motivation, it should be added, since the ordered pairs could themselves be considered as single indices in their own right. The fact that we are privately thinking of these indices as ordered pairs of points need not be mentioned as long as the models...are subjected to conditions guaranteeing that they are either isomorphic to or at least indistinguishable for the logical purposes at hand from models in which truth is relative to pairs of points. Kuhn calls this procedure ... "flattening" a two-dimensional modal logic, though the term is not quite apt, since a two-dimensional object is already about as flat as things can get.

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July 25, 2005

Tea with Lloyd and Su

I went along to the philosophy department at Monash yesterday to hang out with logicians Su Rogerson and Lloyd Humberstone. They have been teaching a rather advanced logic course to a small group of brave undergraduates, and so I got to see them in action before tea.


Here's just one of the things that I learned from Su and Lloyd yesterday:

Some famous Axioms


The system which takes B, C and I as axioms (with uniform substitution and modus ponens as the rules) is known as BCI. BCI is the implicational fragment of Linear Logic. If we add contraction (W) we get BCIW, which is the implicational fragment of the best known relevant logic, R. Adding K (known to relevant logicians as "irrelevance"(!)) instead of W gets us BCK (I follows from K and C.) BCK (under that name, at least) was first studied by Meredith. If we add both K and W we get BCKW, the implicational fragment of intuitionistic logic. To get the implicational fragment of classical logic we need only add Peirce's Law:


So what we have looks like this:


All these axioms possess a confusing multitude of names, so I should mention that B is also known as "prefixing" and C gets called "permutation."

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July 23, 2005

Low-Res Bloggers At Dinner

I presented at a session of Jon Cohen's NotYASS (Not Yet Another Seminar Series) at the Australia National University in Canberra last week, and overcame my dislike of cameras long enough to take an extremely low resolution picture using my phone:


This is Jon with Kenny Easwaran at the Eritrean restaurant we went to after the seminar. NotYASS is a very good thing, I think. Many of the participants are computer scientists and mathematicians, though there were also several philosophers there the night I was presenting, and I think it's good to have a venue for us all to interact. The kind of questions and suggestions one gets at an event like that are different from the ones you might expect from a standard philosophy audience, and that's healthy and interesting, I think. And challenging, of course. (I was psyched to have Bob Meyer in the audience!)

Here's the webpage for the current schedule.

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July 19, 2005

Wish you were here

This post comes live from hut D at the RSSS in Canberra. It's about 40 minutes until the start of the Philosophical Methodology conference but yesterday we had an appropriate trailer in the form of Al Hájek's "Heuristics" paper, which is about heuristics for coming up with philosophical ideas, for papers, questions about other people's papers and the like.

Suggestions included:

"see definite descriptions in neon lights" - whenever someone claims that Y is the X, try to make a case that X isn't satisfied uniquely, or that in some cases there is no satisfier for X, e.g. when Stahlnaker claimed that A[]->B is true just in case at the nearest world where A is true, B is true, Lewis claimed that in important cases there is no nearest world where A is true, e.g. consider the counterfactual "if Bizet and Nietzsche were compatriots, they would both be French." Intuitively there are two equally close worlds (neither such that there is a closer one) in which they are compatriots - one where they are both French, and one where they are both German. (Or, going by one of Nietzsche's crazy early autobiographies, both Polish.) Or consider the nearest world in which "if I were taller than 7 feet tall, I would be better at basketball." There's no closest world at which I'm taller than 7 feet tall, since a world at which I am 7 feet 1/2 inch is presumably closer than one in which I am 7 feet 1 inch, but then 7 feet 1/4 inches is closer still...

"try applying the analysis to itself"

Al has a friend who devised Baker's Laws:

Baker's Law 1: everything tastes better with either chocolate or garlic added.
Baker's Law 2: everything tastes worse with both chocolate and garlic added.

But what about chocolate? And garlic? Each violates law 1, and a mixture of the two violates law 2.

Al gave this talk at the undergraduate philosophy conference yesterday afternoon, and in the talk immediately afterward Kate from Melbourne Uni was trying this second technique out on David Chalmers. Pretty cool.

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July 18, 2005

Top Ten

The BBC's Greatest Philosopher vote has finished, with Marx romping home in first place, and Scotland's own Hume a clear second. The full top ten is:

1. Marx
2. Hume
3. Wittgenstein
4. Nietzsche
5. Plato
6. Kant
7. Aquinas
8. Socrates
9. Aristotle
10. Popper

Nothing too surprising in there, I think. Popper remains immensely popular with scientists, of course, though it would be interesting to see whether he and the other two recent writers - Nietzsche and Wittgenstein - are still on the list in a hundred years time.

Are there any surprising omissions?

Posted by logican at 4:28 AM | TrackBack

Postcard from Sydney

Once again, I'm back from my travels and snatching another 30 seconds with my email and weblog. I think it is ok for me to call these notes - written from Melbourne after my return - "postcards" because I never seem to post ordinary postcards until after I get home either.

And so from 2nd-8th July I was at the conference of the Australasian Association for Philosophy at the University of Sydney. The AAP lists the following quote from Bill Lycan on their website:

Here is a revealing comparison.   For the annual meeting of the American Philosophical Association the Program Committee sifts submissions carefully and rejects 80 percent.  The Australasian Association of Philosophy does not sift submissions. Yet every year the AAP program is better overall than the APA program.

I can't speak for the APA, but having been to the AAP 6 years in a row now, I can say that it is always a fantastic conference. Bill Lycan himself was back to talk about the Gettier problem, David Chalmers talked about verbal disagreements, Ted Sider presented his own version of conventionalism about necessity, Karen Bennett told us why she isn't a dualist, Andy Egan sorted out relativism, Daniel Nolan (Professor Nolan to you now) made me feel bad about my non-theoretically supported beliefs (but gave me a menu of remedies to select from,) and Charles Pigden took on conspiracy theorists' detractors. In dialogue. Written in Shakespearean language. With volunteer actors, who included one of his oponents on this topic. It gave a whole new meaning to "putting words in someone's mouth." There were also papers from other well-known philosophers like Michael Smith, Steve Yablo, Jack Smart, Alan Hajek, Richard Swinburne, John Heil, Laurie Paul...I should never have started this list - there is no way it was ever going to be complete, or even representative...there's a link to the schedule here.

Man, does David Armstrong know how to throw a party.

One of the nice things about the conference this time was that many of the attendees were staying at the University's International House, which provides meals. That meant that I was always running into someone I wanted to talk to at breakfast, and it was easy to have lots of casual interaction with other philosophers. One snippet which I picked up this way was that I should be careful to distinguish intrinsic/extrinsic property distinction from the relational/non-relational property distinction (and not casually conflate them, as I did at the beginning of my conversation with suppering metaphysician Josh Parsons) because some properties are relational but intrinsic, e.g. I have the property of having a nose, and that is intrinsic to me (unlike the property of being an hour's flight from Canberra,) even though I have it in virtue of my relation to something else (my nose.)

A number of bloggers were there including Antimeta's Kenny Easwaran, and David Chalmers, who has photos from the conference up on his website.

When I get round to sending my postcard from Canberra I'll tell you about my meeting with Jon Cohen, who writes that logic blog, That Logic Blog. (He's got blogger pictures up already.)

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July 11, 2005

Change of Title

Greg Restall and I have decided to change the name of our joint paper from "Barriers to Inference" to "Barriers to Implication". The old title sounds good and it respects a tradition in the literature, but it led to some odd situations. At FEW, for example, I found myself asking the aren't-you-conflating-inference-and-implication question after someone else's talk, only to stand up and present our barriers paper and have to sheepishly explain that it wasn't really about inference barriers at all...anyway, Greg and I both accept Harman's distinction, so we thought we'd try to bring our practices in line with our beliefs.

Posted by logican at 11:54 PM | TrackBack

July 10, 2005


There's a new volume of the Australasian Journal of Logic up on the web, and I'm happy to say that it includes my first ever book review - for Goldfarb's Deductive Logic textbook. There are also (a little less self-centeredly) articles entitled "Constant Domain Quantified Modal Logics Without Boolean Negation", "Tonk Strikes Back", "Basic Relevant Theories for Combinators at Levels I and II" and "Justification of Argument Schemes". The AJL is a referreed, internet-only, open-access (i.e., it's FREE) journal (virtues it shares with Philosophers' Imprint). I think they're both very good things.

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July 1, 2005

Return to Form

I hear that two guys and a small dog are still checking in here each day, and so they will have noticed that things have been quiet for a couple of weeks. I went home to England and the unseasonal heat (yes, it is high summer) and the modem between me and the e-world led to me reinventing myself as slothful reader of science fiction paperbacks. But no more macho fantasy for me: I arrived in Melbourne yesterday, where I am staying with fellow blogger and long-term friend Matt Carter and fellow philosopher Sue. They helped me to stay awake until the evening against the protests of my circadian cycle (if my mind is kind of like a computer, couldn't I get something kind of like a reset button fitted for its clock?) Tomorrow I'm off to the AAP, possibly after attending this awesome-looking Music/Film Festival at the Forum. So happy to be back in this city.

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