Peter Smith's Blog, page 87

Postcard from Sicily

We have been back to Sicily for a week, this time to the north-west corner, in and around Palermo and Marsala — visiting the temple at Segesta (above) on the last day, on the way back to the airport. All in all, a delightful trip, and we did a great deal. High points included the obvious ones, visiting some Palermo sights such as the Palantine chapel, going up to Monreale, Erice, etc. Some terrific food and drink. Not least, we caught the first night of a really good production of Madame Butterfly at the Teatro Massimo in Palermo (brilliantly sung, and not too much faffing about from the director).

Ah, I see that there are a number of emails giving lots of corrections to the early draft chapters of IFL2 which I’ll need to deal with next. But first a few days off; we need a holiday to recover from the holiday …

Intro to Formal Logic 2nd ed. — readers wanted!

It’s not so very often in life that you get a shot at putting right something major, that first time around occupied a lot of time and energy, but didn’t turn out as well as you intended. So I’m grabbing at the chance of preparing a second edition of my Introduction to Formal Logic, trying to make a very significantly better fist of it this time around. A contract hasn’t been nailed down yet, but I live in hope …

So where have things got to with the re-write? Well, you can now see the current table of contents of the reworked chapters 1 to 14. However, I am not going to simply post these chapters in an unrestricted way here (there are issues of intellectual property rights).

Still, if you would like to see these chapters, then by all means drop an email to ps218 at cam dot ac dot uk. Put “IFL” in the subject line, and add a few words about yourself (undergraduate student? graduate? professor? just interested in logic?). Then I will happily send you an e-copy of these pages on the understanding that (i) you will not recirculate them, (ii) you will certainly let me know any typos you spot, and (iii) you will give me any comments, large or small, that you have. Student comments of the “that chapter was very helpful” vs “I found that section hard going” are particularly welcome. (Though I guess that it’s too late in the day for comments, however well-meant, of the “I really wouldn’t be starting from here!” or “I wish you’d written a different kind of book!” variety.)

Anyone who produces helpful comments will get further instalments of the book over the next six months, and a mention in the Thanks at the beginning of book! Fame at last: how can you resist?

Meanwhile, I am making the opening chapters freely available — these form the informal pre-amble before we get down to propositional logic, explaining a few logical ideas like validity, forms of argument, counterexamples, proofs, etc. Beginning students who want a logical helping hand might find them useful.

Intro to Formal Logic 2nd ed. — help, please!

If you know my Introduction to Formal Logic reasonably well, and in particular if you have at some time taught from it, do please read on!

CUP suggested over a couple of months ago now that I write a second edition of this textbook. And I have become very taken with the idea. The proposal in headline terms is that the second edition will also cover natural deduction, while losing a little of the stuff which is unnecessarily fancy for a first course. There’s just a bit more detail here. So I’ve been diving into the project (in fact, encouraged by supportive words from my CUP editor, in advance of having a formal contract). I’m well over 100 pages in, doing a very great deal of rewriting, and I think the result is a lot better — well, I would, wouldn’t I!

Now, I have just had a letter from my CUP editor, saying

Although a number of second editions of Cambridge books go forward without a review process, my senior colleagues are taking the view that for a textbook like this one, it would be good to canvass some opinion about the current edition and the changes/additions which you’re planning for the new one. They have put this request to me and to several other editors who are currently proposing second editions of textbooks.

Could you, therefore, come up with some names of people who you know are or have been using the book in teaching and who you think would be willing to give us their opinions? A group of about five or six names, including those of several people based in the US, would be extremely helpful.

Now, although I know of one or two, I confess I’ve not been keeping count of who has been using the text and who hasn’t (not a great number I think, given the sales aren’t exactly keeping me in luxury!). So if you know and like the book well enough to feel able to put in a good word with the Press for the idea of a second edition if they approach you, I’d be very grateful if you could drop me a line to ps218 at the usual cam.ac.uk.   Thanks!

 

CD choice #7 (Bohemian rhapsodies against the Brexit blues)

Another in my sporadic sequence of random CD recommendations. And this is, in fact a recommendation for a sequence of eight disks, called Baroque Bohemia and Beyond (or in one case Bohemian Baroque), with the Czech Chamber Philharmonic, conducted by Vojtĕch Spurný or Petr Chromčák, on the Alto label.

As the titles suggest, these are performances of pretty obscure Bohemian baroque and early classical symphonies and concertos, mostly composed by rough contemporaries of Haydn. Some of the composers are indeed so obscure as not even to have Wikipedia pages in Czech! And yes, the music is charming, diverting, sometimes surprising, and often delightful — but hardly great (and it makes you aware once more just how consistently wonderful Haydn is!). Still, these disks have been — I’ve found — a lovely source of cheer over the last few weeks. Good to listen to while doing some of the typographical chores of converting my logic book into LaTeX for example. And an occasional very welcome and positive distraction from the post-Brexit blues (and the general sense that, politically, the world is going to hell in a handcart).

The eight discs are all freely available on Apple Music (and so, I guess, on other streaming sites?), though they also pretty cheap to buy.

Colour at the Fitzwilliam

Book of Hours, Use of Rome, The Three Living and the Three Dead, Western France, c.1490-1510. Photograph: Michael Jones/The Fitzwilliam Museum

So there you are, out for a spot of hunting and general enjoyment, and these killjoys turn up to remind you of the fate which must, in the end, befall you.  No wonder you don’t look too pleased …

This is from one of the illuminated manuscripts on display in the wonderful new Fitzwilliam Museum exhibition, COLOUR: The art and science of illuminated manuscripts (on until the end of year, free entrance). As now usual at the Fitz, this is a quite beautifully mounted show, and many of the manuscripts on show are little less than astounding. There is a five star review in the Guardian, with links to more illustrations, so I need say no more here. You can also explore further on the museum’s website. We’ll certainly be back. And it is quite definitely worth a trip to Cambridge.

(Tip for non-Cambridge people. Come on a sunny day, as the exhibition should be quieter, with fewer tourists tempted to shelter from the rain.)

Not minding my ‘P’s and ‘Q’s

Books are never really finished.

But the pressure to publish, to have something to show for your time, becomes too great. Or your friendly publisher goes from merely nagging to threatening to take back even your meagre advance if you delay delivery any more. Or you simply can’t, for the time being, face another rewrite. Or all three, in the case of the first edition of An Introduction to Formal Logic. 

As I work through that book again — and fingers crossed that the Syndics of the Press formally agree to a second edition, as I’m now about 100 pages into a rewrite — I’m struck what a really mixed bag that edition is. There are some quite nice episodes, which I still like and which need little reworking; other episodes where things need to be smoothed but which are basically on the right lines; but also far too many places where I need to do a lot better.

And in some of those cases it isn’t just presentational changes that are needed. There are thoughtless foul-ups that require sorting out. There I am, in the old Chapter 10, giving a sermon on minding our ‘’s and ‘’s (propositional letters in a formal language) and distinguishing them from ‘A’s and ‘B’s (schematic variables helpfully added to logicians’ English to help us, inter alia, generalize about wffs in our formal language). And then, dammit, in Chapter 11, when talking about the expressive adequacy of a language with conjunction, disjunction and negation as the built-in connectives,  I find that they are places where I do things in terms of  ‘’s and ‘’s where really I needed, for the intended generality,  ‘A’s and ‘B’s. Hell’s bells. How on earth did I not notice that before, when it should have been glaringly obvious all these years? After all, this is baby logic…

One of those occasions, then, for those uncomfortably mixed feelings known to authors lucky enough to get a second shot at a book (I remember the sensation well, from when I was revising my Gödel book). There is horror at the earlier foul-up, relief that you have spotted it and can make it good, and sheer panic at the thought that if you managed to make that egregious mistake without noticing it for years, there could well be other things, equally bad, that are still passing you by.

Oh, the joys of logical authorship. Wouldn’t be without them for the world, of course.

Duet Display again

I posted about this six months ago. But let me repeat myself, by way of a public service announcement!

If you have e.g. a MacBook of some description (or indeed a Windows machine), and an iPad, you can use the iPad as an additional display. Duet Display works over a USB cable, so it is very much smoother and vastly less flakey in operation than old implementations of the general idea using Bluetooth. OK, it won’t magically increase your “productivity” but it assuredly reduces the irritations of window-juggling when working. Above, there’s my current source code for a LaTeX chapter in a TeXShop window on the left of the 15″ MBA screen, the PDF of the book on the right — and off-loaded to a standard-sized iPad, the TexShop console and a BibDesk window. Of course you could put something more distracting on the secondary screen!

Once you’ve told Duet Display how you have placed your iPad and laptop relatively to each other, the cursor magically goes from screen to screen (and the current menubar moves with it), just as with a multi-monitor set-up. It really does work a treat, extremely stably. And by the way, you can hit the home button on the iPad to navigate to other open apps in the usual way, and then return to Duet Display to pick up there.

You can get Duet Display for the iPad from the app store, and then download the free OSX or Windows companions from their site. If you don’t know it, a very warmly recommended bargain.

Why not ask your local friendly logician?

Logicians are perhaps of rather limited use to the world (as I’m occasionally reminded by Mrs Logic Matters). But they can be tolerably helpful when you are in danger of inadvertently confusing  use and mention, or if you want to avoid getting into muddles about variables, and so on.

Consider this:

A set is merely the result of collecting objects of interest, and it is usually identified by enclosing its elements with braces (curly brackets).

No: what gets surrounded by curly brackets in forming an expression identifying a set are expressions designating the elements, not the elements themselves. (And odd to say that sets are usually identified this way, using lists enclosed in curly brackets, when that only works for finite sets!)

Or how about this:

A property is a statement that asserts something about one or more variables. For example, the two statements “x is a real number” and “ and ” are clearly properties that assert something, respectively, about x and y.

Ok: it makes sense to say e.g. that

“ is a real number” asserts something about ,

because   is a denoting term. But it doesn’t express any complete claim to say that

 ” x is a real number” asserts something about x

if “x” is left as a dangling free variable. And we can’t tidy up by imagining there is a governing quantifier, as you can’t quantify across quotes. Anyway, a property isn’t a statement of any kind (even if we allow open sentences with unbound variables to count as statements) — properties are what are expressed by open sentences, or are their semantic values, or some such.

How about this?

[An example of a compound sentence is]

(means  “P and Q” and is called conjunction)

What convention on quotation marks is in play which would make it right to have the quotation marks this way round? And, being pernickety — but why not? —  it is certainly not the case that the wff is called “conjunction”! It is a conjunction.

Quite rightly, any logician would balk at write each of the above. Not so the mathematician Daniel Cunningham in his brand new book Set Theory: A First Course (CUP, 2016). Those quotations are all from the first six pages.

This seems a huge pity as the book later promises well as an introductory set theory text. I’ll report back in due course on the real content, once the book gets going. But it really is worth talking to your local friendly logician to avoid silly foul-ups like these.

Solomon Feferman (13.xii.1928 — 26.vii.2016)

I’m sad to hear that Solomon Feferman, an intellectual hero of mine, has died.

Those Brexit blues again

The admirable John Lanchester, writes on Brexit in the latest London Review of Books, which has made his piece freely available.

If you are not all Brexited out, then this strikes me as particularly insightful about some of the social currents at work, and more than usually worth a read.