Peter Smith's Blog, page 73

The Pavel Haas Quartet at the Edinburgh Festival

Pavel Haas Quartet
Photo: Marco Borggreve

With their last CD newly shortlisted for another Gramophone Award, The Pavel Haas Quartet have started their new season with a concert at the Edinburgh Festival, playing Shostakovich’s String Quartet No. 7, Schubert’s ‘Rosamunde’ Quartet and the Ravel Quartet. You can listen for another four weeks at the BBC site, here. They are in terrific form – who would guess that they have only been playing with their new violist for half a year? – and the Schubert here is quite exceptional. Catch this concert while you can!

The post The Pavel Haas Quartet at the Edinburgh Festival appeared first on Logic Matters.

Decaffeinated sets

It is a familiar enough point that while logic texts for beginners often fall into talking about sets (sets of premisses entailing conclusions, sets of objects being extensions of predicates, sets of objects being domains of quantification, etc.), this set talk is doing no substantive work at least in elementary contexts. It can be construed in a decaffeinated way, as talk about no more than virtual classes in Quine’s sense.

I found myself making a few remarks to this effect at scattered places in  IFL2, but doing so distracted a bit from the flow of exposition. So I’ve decided to gather together various remarks into one four-page chapter. Here it is:

A very short word about sets

What do people think? I’d very much welcome comments. I don’t want to avoid distractions of one kind by e.g. being thought distractingly misguided!

The post Decaffeinated sets appeared first on Logic Matters.

Mesh wifi – Deco M5

Not my usual sort of post, but this might be of interest to anyone out there dithering about getting a mesh wifi system for home. The take home message? Just do it, you won’t regret it — and the TP-link Deco M5 will probably suit you very well.

And for those still with me,  who want more detail ….

We have a two storey Edwardian house, small but extended, with a lot of internal brick walls. Our Virgin broadband gives 100 Mb/s download speeds in theory. In practice, the wifi from the Virgin Hub 3.0 was — on a bad day — delivering a fluctuating 2 or 4 Mb/s in my study or at the back of the kitchen. OK, we were getting better using two old Apple Airports, but one died recently so it really was time to look for a replacement system. Our needs are modest: ideally, a system delivering steady wifi throughout the house, for ordinary laptop use, some iPlayer or movie streaming to the Apple TV, and (what in particular we didn’t have before) enough bandwidth for reliable quality FaceTime video without sitting next to the router. We have no need for fancy control of the system: plug-and-play-and-forget-about-it is what we were after.

Looking at reviews, in the PC/Mac magazines, on review sites, and from purchasers, it seems that there are a number of mesh wifi systems that get a lot of more-or-less five-star reviews. Though in each case, some purchasers report very bad experiences. So you pays your money and takes your chances …

Some of the systems are definite overkill for a smallish house where the incoming broadband is not lightning fast and where we haven’t got dozens of devices. So I went for the TP-link Deco M5 (there’s now a fancier M9, not yet available in the UK; but this is more expensive and again provides more than we could need so I didn’t wait for it). I plumped for the Deco basically on price — and on aesthetic grounds, where TP-link have taken a leaf out of Apple’s book. The small units and their chargers are rather nicely designed, and even smaller (and hence more unobtrusive) than you expect.

Setting up the three Decos on the iPhone app was simplicity itself. (Odd maybe not to have the option of a Web set up, but since there are no fancy controls, I guess it isn’t needed.) Twenty minutes or so and we were good to go.  (A firmware update became available after a couple of days: oh heavens, I thought, am I about to spoil things, now everything is working perfectly? But no, updating via the app went entirely smoothly first time — another  encouraging sign!)

And so to the 64K dollar question: how well does it all work? We are now normally getting 100Mb/s more or less throughout the house (just a bit slower in one bedroom, it seems) — ‘normally’ meaning so long as the broadband feed from Virgin is behaving. In other words, we are getting the benefit of all the speed we are notionally paying for. The wifi connection has been extremely stable and reliable, with no noticeable dropouts at all. Those transatlantic FaceTime video chats work a treat, far from the Hub. The Decos just sit there, performing as advertised.

So, in summary — for our routine needs — the Decos really do fill the bill. I needed a family prod or three to take the plunge; should have done it a year ago.

The post Mesh wifi – Deco M5 appeared first on Logic Matters.

Old Glory

Now, how did that happen? Wanting to re-read Jonathan Raban’s Coasting, his evocation of a journey of discovery sailing round Britain, first published over thirty years ago, I just found a couple of days ago that our copy has disappeared from the shelves. A mystery:  I wonder what happened to it. So it is very good to discover that the book has recently been republished, along with four other books by Raban, by Eland, in rather handsomely produced paperbacks. I remember the book as being extraordinarily well written. The blurb on our new copy tells me that  Raban here “moves seamlessly between awkward memories of childhood as the son of a vicar, a vivid chronicle of the shape-shifting sea and incisive descriptions of the people and communities he encounters. As he faces his terror of racing water, eddies, offshore sandbars and ferries on a collision course, so he navigates the complex and turbulent waters of his own middle age. Coasting is a fearless attempt to discover the meaning of belonging and of his English homeland.” Which indeed is how I recall the book. I look forward to it!

I’ve been put in mind to read Coasting again because I have recently been re-reading with great  enjoyment two of Raban’s other books that are on our shelves (as it happens, another two of the five that have been republished by Eland). First there was For Love & Money, which is subtitled “Writing, Reading, Travelling: 1969–87”, and which reprints some early reviews and occasional pieces. The writing is consistently humane and insightful, but more than that, it is just so beautifully readable (the number of times I thought, “I wish I could write even half as well”). And then there was Raban’s early masterpiece, Old Glory from 1981, notionally recounting his voyage down the Mississippi in a small boat.

I say “notionally” as this complex work is lightly disguised as a straight travel book, a literal recounting of a journey taken. But the one-time English literature lecturer warns us clearly enough. One of the epigraphs of the book is from T. S. Eliot (writing of the  Mississippi), starting “I do not know much about gods; but I think that the river/Is a strong brown god …” The other epigraph is from Jean François Millet: “One man may paint a picture from a careful drawing made on the spot, and another may paint the same scene from memory, from a brief but strong impression; and the last may succeed better in giving the character, the physiognomy of the place, though all the details may be inexact.” So we are set up for this to be a mythic tale, and for the “Jonathan Raban” who features as the narrator and his adventures to be a very inexact rendition of the author and his own journey. And a mythic tale is what we get, an ordeal by water, with auguries and signs, battles fought, a princess won (but also lost, for this is a flawed epic, and the journey ends in emptiness). But woven together with this are encounters with American myths of frontiers and journeys. And, presciently — so striking, reading again now, nearly forty years later —  Raban notes the “deep, unsatisfied capacity for hero-worship” that makes many Americans (far from the artificialities of the coasts) long for a “strong” leader, a saviour. This is a many layered book, artful in the artlessness of its transparent prose. Wonderful.

The post Old Glory appeared first on Logic Matters.

Getting it right …

After a bad day battling with my intro logic book and feeling really rather despondent about it, I stumbled over this, from Philip Roth, whose Americal Pastoral I’m currently reading:

“Writing turns you into somebody who’s always wrong. The illusion that you may get it right someday is the perversity that draws you on. What else could? As pathological phenomena go, it doesn’t completely wreck your life.”

Yes, one day, I will get it right …

The post Getting it right … appeared first on Logic Matters.

IFL2: the introductory chapters again

After a hiatus, back to work on the second edition of my Introduction to Formal Logic. I’ve been tidying and (I hope!) slightly improving again the first tranche of chapters — so here they are again:

IFL2: Chapters 1 – 7

A quick look at the Table of Contents should give you a good idea of what they are about if you don’t know the book. If you do know the first edition, then the main change is that I now take a somewhat different line about the notion of logical validity.

The headline news, anyway, is that these really are introductory chapters (general scene-setting before we start work in earnest on propositional logic in Chapter 9).  So I introduce ideas like: validity, deduction vs induction, showing validity by ‘proofs’, showing invalidity by ‘counterexamples’, logical validity vs validity (necessary preservation of truth more generally). The chapters aim to be accessible and reasonably user-friendly without talking down to the reader. So these chapters hopefully should be of interest and of use to any philosophy student about to start a logic course next term/semester (indeed, they should be of use to any beginning philosopher). Do please spread the word, and do point prospective students to the link!

I’ll leave these chapters online, freely available, for the next couple of months or so. In the meantime, all comments/corrections as always most gratefully received!

The post IFL2: the introductory chapters again appeared first on Logic Matters.

In wonderland

A Cambridge story, from Arnie Koslow.

Back in the day, the Moral Sciences Club met in the rooms of Richard Braithwaite, then the Club’s chairman. A sofa at the front provided the regular seating for the nervous figure of Alfred Ewing at one end and the obscurely oracular John Wisdom at the other.

One meeting, the room is packed, and a latecomer hovers at the door, looking for somewhere to sit.

From the chair, Braithwaite booms “There is space on the sofa … between the March Hare and the Mad Hatter.”

The post In wonderland appeared first on Logic Matters.

A reading resolution kept!

For some years now, I’ve kept a list of the novels that I’ve being reading or re-reading  — my memory for this sort of thing being pretty bad. But the list used to grow depressingly slowly; so very many good (or better!) novels, more coming out every month, and so little time, it seemed, to read them. This year, then, I made a New Year’s Resolution: really cut-back on non-work-related internet in the evenings. I’ve never been one for FaceBook, though Twitter can be addictive. But how the hours can disappear on newspaper/magazine sites, other political sites (especially in these days of Brexit and Trump), arts/music sites, not to mention nerdy stuff …! So I, as I say, I resolved to Cut Right Down.

And for once, this is a resolution that has been kept pretty well. In the last six months, I’ve now read as many novels as the whole of last year — and had much more enjoyable and relaxing evenings into the bargain. I can honestly recommend it hugely.

There’s no real pattern or plan to my reading. I usually just take down from the shelves something old or new that appeals at the time — and the shelves are an pretty eclectic mix, given that Mrs Logic Matters and I both have a taste for browsing charity-shops for serendipitous finds. But I do make a rule of reading a Dickens every winter! — so this year, I lapped up Dombey and Son (which I confess I hadn’t read before as an adult). And, since it is his bicentennial year, I thought I’d try to read or re-read a good amount of Turgenev, who I do find particularly appealing. More about him, perhaps, another time.

My big recent discovery has been the novels of Helen Dunmore. I was very taken with her late novel Exposure earlier in the year; here’s an insightful review by Kate Clanchy. And then a bit later I was in a charity shop — serendipity indeed! — as they were putting on the table a set of completely-as-new recent paperback copies of her first ten novels which had been donated a few mintues before. So I snaffled the lot, and am now beginning to read her novels in chronological order. A poet as well as a novelist, Dunmore’s are beautifully written as well as wonderfully thoughtful books.

What else? Let me just mention three for reading on a summer’s night for sheer enjoyment. The latest Sarah Dunant, In the Name of the Family, takes up her fictional but historically rich version of the Borgias where Blood and Beauty leaves off. If you don’t know the earlier book, you really are missing a treat: if you do know it, you’ll have surely read the sequel already. Six months or so ago, Gail Honeyman’s Eleanor Oliphant is Completely Fine was top of the paperback bestseller lists. We’re usually a bit resistant to hype; but we started reading it in a bookshop on an enthusiastic recommendation — and were hooked. But the book I’ve loved most of all in the last six months is one from 1979 which I’d never read before, Penelope Fitzgerald’s tragi-farce (her word) Offshore. Here’s a nice piece about it by Alan Hollinghurst. Sheer delight on many levels.

The post A reading resolution kept! appeared first on Logic Matters.

[Security, etc.]

[Just an update to say that I have now installed an SSL certificate so that this becomes a “secure” site served via https, which will stop some browsers telling you this isn’t a secure site. I’ve also moved domain registrar and done other stuff behind the scenes. Let me know if I have broken anything!]

The post [Security, etc.] appeared first on Logic Matters.

It is not the case that p

You can of course very often express the negation of p  by saying ‘it’s not the case that p’.

But some logicians in intro texts incautiously claim more — saying something like “This is cumbersome, but it works in every case” (that’s a quote, but no names, no pack drill!).

However it surely overshoots to claim that prefixing  ‘it’s not the case that’ by itself produces the negation of what you start with in every case. Here are some examples:

Jack loves Jill, or Jill is much mistaken about Jack’s feelings.
It’s not the case that Jack loves Jill, or Jill is much mistaken about Jack’s feelings.

Aren’t both  true if Jill is sadly mistaken?

Jack loves Jill and it’s not the case that Jill loves Jack.
It’s not the case that Jack loves Jill and it’s not the case that Jill loves Jack.

Aren’t both false if Jill loves Jack?

Jones, who is a Russian agent, loves caviar.
It’s not the case that Jones, who is a Russian agent, loves caviar.

Aren’t neither true if Jones isn’t a Russian agent?

So what are your favourite counterexamples to the claim that ‘it’s not the case that p’ always expresses the negation of p?

The post It is not the case that p appeared first on Logic Matters.