Category Archives: This and that

Postcard from Cornwall

A photo taken along the South West Coast Path, as it runs to St Anthony Head in Cornwall. It’s a particularly beautiful stretch of the path, and a quick ferry ride takes us across the bay from the apartment we rent this time of … Continue reading

Posted in This and that | Leave a comment

Maddy on sets, categories, and the multiverse

Here are three large-scale issues. First, in what good sense or senses, if any, does ZFC provide a foundation for mathematics. Second, can category theory provide an alternative(?), or better(?) foundation for some or all mathematics? Third, should set theory … Continue reading

Posted in This and that | 2 Comments

Empty domains #3 – from Vej Kse

The following was posted as a comment to Empty domains #1 by Vej Kse — but I think it is particularly interesting and worth highlighting as a stand-alone post.  There is an elegant and natural (from a user’s perspective) way to allow … Continue reading

Posted in This and that | 7 Comments

Empty domains #2

Here is a long quotation from Oliver and Smiley in their Plural Logic, motivating their adoption of a universally free logic (i.e. one allowing empty domains and empty terms). If empty singular terms are outlawed, we are deprived of logic as a tool … Continue reading

Posted in This and that | 6 Comments

New foundations?

This I find intriguing: Can we actually use [homotopy] type theory as the foundation for mathematics? That is, must we consider the objects of mathematics to “really” be built out of sets, with “types” just a convenient fiction for talking … Continue reading

Posted in This and that | 5 Comments

As good as it gets

We have been to some excellent local concerts over the last few months which I haven’t mentioned here (from the likes of Igor Levit, Rachel Podger and the English Concert, Cuarteto Casals, and a particularly on-form Academy of Ancient Music … Continue reading

Posted in This and that | Leave a comment

David Makinson’s Sets, Logic and Maths

As I go through chapters of my Introduction to Formal Logic, heavily rewriting them for the second edition (only scattered paragraphs are surviving unaltered from the first edition, and I’m adding wholy new chapters too), I’m occasionally pulling other introductory books … Continue reading

Posted in This and that | Leave a comment

Dennett: losing the plot

I’ve tried to read Daniel Dennett’s From Bacteria to Bach and Back. But I’ve lost the plot, and given up quite early in the book. I seem to now find Dennett’s penchant for metaphors, claims that are “sorta” true, analogies, free-wheeling speculation, his having-his-cake-and-eating-it … Continue reading

Posted in This and that | 2 Comments

Going cold turkey

I can’t say I’m surprised that an election has been called. As it becomes clearer and clearer (to the Tories in power — they were warned!)  how horribly long and messy and potentially disastrous the Brexit process will be, you can see why Theresa May, her Chancellor, and … Continue reading

Posted in This and that | 3 Comments

A word for our times

TrumpBrexiety (© Lucy Mangan)

Posted in This and that | Leave a comment