Bergen Logic Group

Logic, Reasoning, and Justification

A one-day in-person workshop organized by the Department of Philosophy, University of Bergen.

 A triangle drawn in two dimensions but showing a shape that is impossible to reproduce in three dimensions
愚木混株 cdd20

Main content


10.00 Coffee

Greg Restall (Univ. of St. Andrews)
Proofs for Relevant Consequence, with Star and Perp
In this talk, I show how to incorporate insights from the model-theoretic semantics for negation (insights due to J. Michael Dunn, in his paper “Star and Perp: Two Treatments of Negation’’), into a proof-first understanding of the semantics of negation. I then discuss how a logical pluralist may understand the underlying accounts of proofs and their significance. The result is a new perspective from which to view the connection between relevance and different notions of logical consequence.

Shawn Standefer (National Taiwan University)
Extensionality, intensionality, and hyperintensionality in non-classical logics
In this talk, I will present the distinction between extensional, intensional, and hyperintensional contexts in propositional logic. I will examine this distinction in the context of some non-classical logics, especially relevant logics. I will argue that relevant logics are, by their own lights, hyperintensional. As such, this makes them excellent logics for investigating phenomena that need hyperintensional analysis.


Anna-Sara Malmgren (Inland Norway University of Applied Sciences)
Another problem that logic (probably) can’t solve
There are many problems that logic can’t solve. The conflicts in the Middle East, the problem of evil, the climate crisis, and ordinary marriage problems, are plausibly among those: with some obvious qualifications, we don’t expect the application of formal tools to lead to radical breakthroughs in our efforts to resolve them. This talk is about a problem that might seem different: one that it’s more tempting to think that logic can solve, or at least throw considerable light on. It’s a puzzling underspecification problem in the theory of justification that I call 'the problem of relevant completeness'. On reflection it’s not that surprising that logic can’t solve this problem either. But then how should it be approached?

Alex Paseau (Oxford)
What is Formalisation?
Turning informal language into symbolic form is the logician's art. But what is this art, skill, or possibly science, logicians are so adept at? What criteria guide it? You might expect the question to have an easy answer given that logicians are as a group excellent formalisers (almost by definition). But practice is one thing and theory another, and logicians or philosophers of logic have so far not greatly clarified what formalisation consists in. My talk’s aim will be to take a step towards a more complete list of criteria of acceptable or good formalisation. It will thereby cast some light on the main function of a logic: capturing logical consequence.