Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland.
I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other.
I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy.
Posts
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
My *next* talk in this spring/summer of research combines some longstanding interests of mine (Graham Priest’s Logic of Paradox) and more recent interests (natural deduction and the sequent calculus). I bet you didn’t think that you could creatively apply Gentzen’s thoroughly standard rules of natural deduction to give you a sound and complete calculus for Priest’s LP, but it turns out that you can.
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
It’s neat to see that an old (fiddly, complicated) decidability argument I wrote up in the 1990s is getting some attention. Here, Raj Goré and Anthony Peigné formalise (and generalise) my decidability argument for display formulations of some substructural logics. This is interesting work, worth looking into.
https://link.springer.com/article/10.1007/s11225-026-10239-8
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
I’m looking forward to spending time today with @ohad@mathstodon.xyz, @modaltype@types.pl and other folks at the LFCS at Edinburgh, and getting to talk about some weird substructural modal logic.
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
We’re at that time of the semester in Advanced Logic, where we’re checking our understanding of the key concepts we’ll rely on in our final ascent to the heights of the incompleteness theorems.
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Oh, look! In a few weeks time I’m going to be over in Edinburgh, giving a talk the LFCS. https://informatics.ed.ac.uk/lfcs/lfcs-seminar-tuesday-5th-may-greg-restall
If you’re in town on May 5 and like crazy proof theory, this could be fun. I’ll be talking about what happens when you take a hypersequent calculus for the modal logic S5, and *thoroughly* linearise it, removing all traces of contraction and weakening. The result is stranger than you might think. (Well, it was stranger than I first thought, anyway.) Along the journey we experience strange algebras, cut elimination and decidability arguments, and weird local/global perspective shifts. I learned a lot when thinking about this stuff, so hopefully the audience gets something out of it, too.
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
This Easter season, my church has held an art exhibition on the theme of betrayal, and a short set of reflective services on Maundy Thursday, Good Friday and Holy Saturday.
I was invited to give a short reflection at the Saturday service, and since I have a website to archive my presentations, I’ve uploaded the text of the reflection: https://consequently.org/presentation/2026/holy-saturday-reflection/
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
I’m glad to be back in Glasgow today, this time to give a presentation at the Philosophy Department Senior Seminar. (Seeing the early signs of spring on the train journey from Dundee to Glasgow is an added bonus.)
https://consequently.org/presentation/2026/must-do-mdb-better-glasgow/
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic
This Thursday evening, I will attempt (with some eminent colleagues) to settle longstanding and important questions on the status of mathematics, in a somewhat informative and entertaining fashion, and in the form of a traditional debate.
https://www.stadebates.com/event/05d3ec26-5f9a-4f93-9952-8c9197152b19
Philosopher and logician, from Australia, now based at the University of St Andrews in Scotland. I like thinking about—and helping other people think about—logic and philosophy and the many different ways they can inform and enhance each other. I suppose I’m known for work on substructural logics, logical pluralism, and (more recently) what philosophers should know about proof theory, and proof theorists should know about philosophy. #philosophy #logic