Carlo Rovelli’s inspiring “Relational Quantum Mechanics” serves several aims at once: it provides a new vision of what the world of quantum mechanics is like, and it offers a program to derive the theory’s formalism from a set of simple postulates pertaining to information processing. I propose here to concentrate entirely on the former, to explore the world of quantum mechanics as Rovelli depicts it. It is a fascinating world in part because of Rovelli’s reliance on the information-theory approach to (...) the foundations of quantum mechanics, and in part because its presentation involves taking sides on a fundamental divide within philosophy itself. (shrink)

I think van Fraassen is right to see the development of quantum mechanics as a turning point for physical science with a profound moral for philosophy, and not just for the philosophy of science. But the moral is not that even a completely successful physical theory may fail to account for the appearances by showing how they arise within the reality it represents. The moral is more radical: it is that a physical theory – even a fundamental theory – may (...) be completely successful in all its applications without offering a representation of reality at all. (shrink)

[This paper is part of a book symposium on Bas van Fraassen's Scientific Representation: Paradoxes of Perspective (OUP, 2010)].

There is no distinct correspondence theory of truth, truth is correspondence to fact. If facts are taken to be true propositions, we wind up with just another version of the correspondence theory's ostensible competitor, the redundancy theory of truth. If instead facts are taken to be Armstrong's states of affairs, or Tractarian facts, or Mellor's _facta<D>, we get a _truthmaker<D> principle, that for every truth there is a truthmaker; something whose existence implies the proposition in question. Truthmaker principles are interesting (...) and useful, but go far beyond truth as correspondence with fact, and so are not really theories of truth at all. (shrink)

A recent article argues that the modal interpretation of quantum mechanics does not do justice to immediately repeated non-disturbing measurements. This objection has been raised before, but the article presents it in a new, detailed, precise form. I show that the objection is mistaken.