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Welcome to the new-style blog. Click on a title to see the full post.

New version website

I said a week or so ago that I was going to investigate moving the Logic Matters website from its current expensively hosted Wordpress incarnation to a (slimmer?) version hosted for free on GitHub. With a lot of help from Gemini and Claude I have a working version up and running, which you are now reading! Check it out: all comments most welcome. I will no doubt tinker with the look and feel of the pages, but for a minimalist first attempt, I am pretty pleased.

Twenty years on, what next?

The Logic Matters blog started on 9 March 2006. Bother! – I missed its twentieth birthday. Raise a belated glass, as that was a milestone of sorts.

Felicity Lott, 1947 – 2026

There have been so many moving obituaries and fond tributes. Here, to mark her passing, is Felicity Lott at the start of her stellar career, singing Pamina at Glyndebourne, almost fifty years ago. How joyous. And there was, by the way, a wonderful episode of This Cultural Life on the BBC a few days ago, a conversation with Felicity Lott, broadcast the day before she died: a life well lived.

ICT paperback is out!

The revised/corrected third edition of Introducing Category Theory is now available as a paperback. To keep the cost minimal, this is again via print-on-demand from Amazon US, Amazon UK, and of course other Amazons too, with ISBN 1068346728.

Proof-reading, with a bit of help from LLMs

What have I learnt over recent weeks, preparing a corrected version of Introducing Category Theory, invoking – at various stages – my friends Claude, Gemini and ChatGPT as proof-reading assistants? Not very helpfully, the take-home message is that LLMs are both extremely useful and also surprisingly bad at proof-reading. To explain …

A new version of ICT

The end is in sight. I have just uploaded another PDF of Introducing Category Theory (now identified as Version 3.4 on the verso of the title page – you might need to clear your brower’s cache to force a download of the latest, greatest, version). Never say never, but I hope no further significant changes will be needed before I set up a paperback version. Fingers crossed.

On the mathematical abilities of LLMs

A very interesting new blog post by Tim Gowers on his recent experiences with ChatGPT 5.5 Pro. A headline: “I would judge the level of the result that ChatGPT found in under two hours to be that of a perfectly reasonable chapter in a combinatorics PhD.” Well worth reading.

Another categorical update

The Victorian floor of my tiny study slopes and dips quite badly and it would have been expensive to engineer a flat, level, surface. So, to finish the redecoration, it has had to be new carpet. No majolica tiles for me. Not like this one (now in the Fitzwilliam Museum), from the series which Isabella d’Este used in her studiolo.

Categorical update

I am still working again through the third edition of the category theory book, correcting typos in the first printed version (fortunately, relatively few are possibly misleading), correcting thinkos (cheeringly not many), rewording a few too-contorted sentences (again pleasingly few), slightly improving some sign-posting, and deleting a few over enthusiastic exclamation marks and the like.

Categorically diverted

Another six large-carrier bags of books have gone to Oxfam. And my tiny redecorated study is at last put together again, and – a miracle! – with no books in piles on the floor. Rather late in the day, it is the nicest-looking room I have ever had. The Morris paper is a real delight. A new dim-out blind works a treat, radically reducing distracting reflections in my large Apple monitor. Gemini has explained how to reassemble a better minimalist music system from kit I already had. So suitably inspired, back to work!

Three books, no toast

With my mind partly on revising the Study Guide, I have been browsing through three relatively recently published logic books. None of them impress as candidates for self-study. I will be brief (unfairly? life is short …).

Partial functions and Church’s Thesis

Alex Oliver and Tim Smiley’s magnum opus Plural Logic runs to some 340 pages before the end matter in the second edition. The final chapters are heavy going, involving detailed developments of some cumbersome (indeed, uninviting) formal theories. I wouldn’t be surprised if few readers have made it to the ‘Postscript’ touching on unfinished business.

Great expectations

Well, that all took rather longer than expected … A lot of repairing and filling and preparation (the joys of a late Victorian house). But at last the miniature room that counts as my study is redecorated. A carpet remains to be laid in ten days, but I’ll be able to reshelve the books in logic corner before then, once the new paint is safely “cured”. A pity to hide the William Morris wallpaper mutters Mrs Logic Matters: but needs must.

Since it is the Feast of the Annunciation …

Some of my very favourite paintings are Annunciations … the stunning Leonardo and Botticelli in the Uffizi, the lovely small painting from a predella by Domenico Veneziano close to home in the Fitzwilliam, the wonderful Filippo Lippi in the National Gallery.

But here instead is the rather strange but still very striking Annunciation, with Saint Emidius by Carlo Crivelli, also in the National Gallery.

Hoffmann, Limits of Mathematics

In the last couple of years, Dirk Hoffmann has published English translations of two of his books which originally appeared in German. In 2024, he gave us Gödel’s Incompleteness Theorems (Springer), which I will discuss in a future post. And then last year he published Limits of Mathematics: A Journey Through the Key Areas of Mathematical Logic (Springer), translating the third edition of his Grenzen der Mathematik.

Gödel, slowly …

As I said some weeks ago, I am slowly revising my Introduction to Gödel’s Theorems; I am still only about a third of the way through. I haven’t yet spotted any real horrors, but I’ve found some ways of re-arranging the material for the better, and there are quite a few sections which now strike me as not quite as relaxed and accessible as they should be. I started off planning a mildly revised reprint; but it looks as though the book will end up sufficiently changed for the result to count as a new edition later this year.

A Wittgenstein problem …

It is time at last to redecorate my small but now rather depressingly shabby study.

Gödel, Lean, Fra Angelico, Schubert

So far – but then I am still in the foothills, tinkering with early chapters – I have found just a couple of minor expositional stumbles in An Introduction to Gödel’s Theorems. I have spotted, though, quite a few places where I can make the text run just that bit more smoothly. And my friend Gemini Pro has also chipped in with perhaps two or three helpful small suggestions per chapter.

Gödel’s Theorems (and logicisms) revisited

I didn’t at all intend to return to my Introduction to Gödel’s Theorems (which I’ve not really read for a dozen years, apart from correcting a small handful of typos in the PDF). But I had occasion to look something up, and – hey, ho! – I’ve found myself over the last week beginning to tinker with early chapters (so far in very minor ways, for added clarity). And having started, I guess will intermittently continue. Not that I’m planning any major changes: I much like the structure of the book as it is. I’ll just be maximising accessibility, and perhaps adding footnotes pointing to a few…

ICT, the third edition

There comes a tipping point, when the prospect of yet another round of proof-reading becomes intolerable and you think, dammit, the book as it is will now just have to do! So I have drawn a line, put the latest version of Introducing Category Theory online, set up the printing of a paperback, and will organize a hardback too.

New Issue: Journal for the Philosophy of Mathematics

The first issue of the new Journal for the Philosophy of Mathematics appeared back in September 2024. A second issue, now edited by Alex Paseau, has now appeared, just a day before the end of 2025. This is a collection of just seven, again mostly invited, pieces. And despite the officially quite wide-ranging remit of the journal, five of the seven papers are about sets and pluralities.

Two books to miss? Brandom and Bardi

More than twenty years ago, Robert Brandom wrote Making it Explicit, a 762 page ramble of hand-waving pretentiousness. The sort of philosophical tome I detest. His shortened version Articulating Reasons just exposed how creaky the whole Brandomian edifice is – my esteemed colleague Alex Oliver had fun taking a bash in the LRB.

The Big Red Logic Books – last year, this year.

As I have said more than once before, self-publishing was exactly appropriate for the Big Red Logic Books. I am way past the stage of needing the brownie points that are gained by continuing conventional publication. The books are aimed at students, so why not make them available as widely as can be? — free to download as PDFs, for those happy to work from their screens, and at minimal-cost as print-on-demand paperbacks for the still significant number who (faced with a long text) prefer to work from a physical copy. What’s not to like?

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