Matthias Egg

Primitive ontology and quantum state in the GRW matter density theory

The paper explains in what sense the GRW matter density theory (GRWm) is a primitive ontology theory of quantum mechanics and why, thus conceived, the standard objections against the GRW formalism do not apply to GRWm. We consider the different options for conceiving the quantum state in GRWm and argue that dispositionalism is the most attractive one.

Expanding Our Grasp: Causal Knowledge and the Problem of Unconceived Alternatives

I argue that scientific realism, insofar as it is only committed to those scientific posits of which we have causal knowledge, is immune to Kyle Stanford’s argument from unconceived alternatives. This causal strategy (previously introduced, but not worked out in detail, by Anjan Chakravartty) is shown not to repeat the shortcomings of previous realist responses to Stanford’s argument. Furthermore, I show that the notion of causal knowledge underlying it can be made sufficiently precise by means of conceptual tools recently introduced into the debate on scientific realism. Finally, I apply this strategy to the case of Jean Perrin’s experimental work on the atomic hypothesis, disputing Stanford’s claim that the problem of unconceived alternatives invalidates a realist interpretation of this historical episode. 1   Stanford’s Argument from Unconceived Alternatives 2   Previous Attempts to Undermine the Problem of Unconceived Alternatives    2.1   The plausibility of unconceived alternatives    2.2   The distinctness of unconceived alternatives    2.3   The induction from past to present 3   Causal Knowledge as a Criterion for the Realist    3.1   How Chakravartty’s proposal differs from earlier causal strategies    3.2   Causal realism and the detection/auxiliary distinction 4   Causal Realism, Unconceived Alternatives, and the Atomic Hypothesis    4.1   Perrin and the philosophers: some initial observations    4.2   Roush and Stanford on Perrin    4.3   From Brownian motion to the reality of atoms    4.4   What we know about atoms 5   Conclusion 1   Stanford’s Argument from Unconceived Alternatives 2   Previous Attempts to Undermine the Problem of Unconceived Alternatives    2.1   The plausibility of unconceived alternatives    2.2   The distinctness of unconceived alternatives    2.3   The induction from past to present    2.1   The plausibility of unconceived alternatives    2.2   The distinctness of unconceived alternatives    2.3   The induction from past to present 3   Causal Knowledge as a Criterion for the Realist    3.1   How Chakravartty’s proposal differs from earlier causal strategies    3.2   Causal realism and the detection/auxiliary distinction    3.1   How Chakravartty’s proposal differs from earlier causal strategies    3.2   Causal realism and the detection/auxiliary distinction 4   Causal Realism, Unconceived Alternatives, and the Atomic Hypothesis    4.1   Perrin and the philosophers: some initial observations    4.2   Roush and Stanford on Perrin    4.3   From Brownian motion to the reality of atoms    4.4   What we know about atoms    4.1   Perrin and the philosophers: some initial observations    4.2   Roush and Stanford on Perrin    4.3   From Brownian motion to the reality of atoms    4.4   What we know about atoms 5   Conclusion

Scientific realism in particle physics : a causal approach

Does particle physics really describe the basic constituents of the material world or is it just a useful tool for deriving empirical predictions? This book proposes a novel answer to that question, emphasizing the importance of causal reasoning for the justification of scientific claims. It thereby responds to general worries about scientific realism as well as to more specific challenges stemming from the interpretation of quantum physics.

What Is Kitcher’s Real Realist Really a Realist about?

Summary I review Philip Kitcher’s defence of scientific realism against the so-called pessimistic induction. While supporting his overall strategy, I claim that there is a lacuna in Kitcher’s argument, which needs to be filled by spelling out more precisely what parts of scientific theories we should be realists about. I attempt to do this and to show that scientific realism can thereby not only be protected against the pessimistic induction but also against a recent argument by Kyle Stanford, known as the “new induction”.