Quarterly Lectures on
Philosophy of Science

Abstract

The Modal-Hamiltonian Interpretation (MHI) of quantum mechanics belongs to the modal family: it is a realist, non-collapse interpretation, according to which the quantum state describes the possible properties of a system but not its actual properties. In particular, the Hamiltonian of the closed quantum system plays a decisive role in the rule that selects the definite-valued observables of the system.

In this presentation the speaker focuses on three points: (a) The MHI is effective in solving the measurement problem, both in its ideal and its non-ideal versions. (b) The MHI can be reformulated under an explicitly Galilean-invariant form in terms of the Casimir operators of the Galilean group. (c) According to the MHI, quantum systems are not individuals, but bundles of the type-properties represented by the observables of the system.

Vorbereitungslektüre

Background Reading

• Not Individuals, Nor Even Objects
• Folien / MaterialSlides / Material

Arnon Levy — Covid-19 Modeling and the Science-Policy Nexus

The appropriate role of scientists in shaping policy is both a philosophically interesting issue and one that has broader socio-political significance. This was brought out dramatically during the Covid-19 crisis. Of particular note was the role of infectious disease modelers, and in particular a group in Imperial College London. My overarching claim is that responsibility for both the process and outcomes of policy-making should remain firmly on the shoulders of political leaders and government officials.

Vorbereitungslektüre

Background Reading

• Birch (2021); Winsberg and Harvard (2024); Streicher, Broadbent, and Hellwell (2025)
• Grüne-Yanoff (2021); Gelfert, John, and Frisch (2025)

Abstract

It is often said by physicists that whereas in classical physics complex numbers are a useful but ultimately dispensable mathematical tool, in quantum mechanics they become necessary or essential to formulating the theory. In this talk, the speaker argues that a remarkably illuminating reason for the special naturalness of complex numbers flows from distinctively quantum phenomena involving spin.

Vorbereitungslektüre

Background Reading

• D. Albert, Quantum Mechanics and Experience (through page 43)
• J. Barrett, Conceptual Foundations of Quantum Mechanics, chs. 2–4
• J. Ismael, Quantum Mechanics

Abstract

Models enable an epistemic agent to understand reality in ways that she could not do if she restricted herself to the unvarnished truth. They simplify, streamline, and distort. The regularities a model reveals are real and informative. But many of them show up only under idealizing assumptions. Models facilitate and channel inferences. The construction and use of models thus underscores the way that epistemic agents advance understanding by contriving representations that foster their epistemic ends.

Vorbereitungslektüre

Background Reading

• C. Elgin, True Enough, Chapter 12

Abstract

Factivism about scientific explanation holds that the explanations generated in science must be true to succeed. Many of our best scientific explanations incorporate idealizations — false assumptions. In this talk, the speaker proposes reframing this debate away from whether it is possible to maintain factivism come what may, to instead recognize the philosophical fruitfulness of how departures from the truth facilitate explanation and, thus, understanding.

Abstract

Models matter. This lecture focuses on representational models — models that stand for a selected part or aspect of the world. The lecture introduces the DEKI account of representation (Denotation, Exemplification, Keying-up, Imputation), which traces the origins to Goodman and Elgin's notion of "representation as."

Vorbereitungslektüre

Background Reading

• R. Frigg & J. Nguyen, Models and Theories: A Philosophical Inquiry (OA)
• R. Frigg & J. Nguyen, Modelling Nature: An Opinionated Introduction to Scientific Representation

Abstract

An overview of the philosophical view called Perspectival Realism as articulated in Massimi (2022, OUP). The talk presents the epistemological approach to science that underpins the view with the question of how reliable scientific knowledge is produced, and elucidates the realist position with a focus on a phenomena-first ontology.

Vorbereitungslektüre

Background Reading

• M. Massimi, Perspectival Realism (OUP 2022)

Abstract

How, if at all, can scientific progress improve our view of the modal facts? According to rationalist approaches to modal epistemology, science has no substantive role. According to modal naturalist approaches, science provides evidence about the structure of the underlying modal space. This lecture distinguishes four versions of modal naturalism, with science playing an increasingly robust evidential role.

Vorbereitungslektüre

Background Reading

• A. Wilson, The Nature of Contingency: Quantum Physics as Modal Realism

Abstract

Methodological naturalism is the view that metaphysicians ought to follow as much of the methodology of science as possible. This lecture presents an argument for methodological naturalism and explores some interesting consequences, then turns to what appears to be the most significant challenge: the context-dependence of scientific methodology.

Abstract

Symmetries are sometimes taken to explain conservation laws rather than vice versa. However, it is not easy to see how to justify this direction of explanation. This talk presents an epistemic account of explanation and the conditions that would have to be fulfilled in order for symmetries to explain conservation laws (but not vice versa).

Talks

1. Andréka & Németi: Relativistic computation
2. Cuffaro: Quantum Computing's Impact on the Foundations of Computational Complexity Theory
3. Zdeborová: Analysis of computational hardness via phase transitions
4. Panel discussion

Vorbereitungslektüre

Background Reading

• Duwell (2021): Physics and Computation

Abstract

Scientists violate principles and practices of routine science to quickly develop interventions against catastrophic threats. This lecture defends two principles to assess fast science: it should satisfy as much as possible the reliability-enhancing features of routine science, and should not depend on the same problematic assumptions as the science estimating the magnitude of the threat.

Abstract

Metaphysics is often held to be continuous with science. And in many respects it is: it has similar aims and may even employ a similar methodology. However, it is arguably very different in one crucial respect: while science clearly makes progress, it is very much less clear that metaphysics does. This talk explains why and responds to objections.

Abstract

Debates about scientific realism and debates about scientific or naturalized metaphysics are generally conducted in isolation from one another. As it happens, these two debates are in fact interwoven, because different approaches to scientific realism reflect different approaches to naturalized metaphysics, and antirealist arguments in the former domain have correlates in the latter.

Abstract

This talk introduces the operational theories approach to research in quantum foundations. The space of operational theories is analogous to the space of possible worlds employed in the possible world semantics for modal logic, so research of this sort can be understood as probing modal structure. Thus operational axiomatisations of quantum mechanics may be interpreted as a novel form of structural realism.

Abstract

A quick rehearsal of the schematic form of the Aspect experiment to test Bell's Inequalities. Then an explanation of how those inequalities can be deduced if we assume Reichenbach's common cause principle, and next, if we assume counterfactual definiteness (made precise in terms of conditionals). Finally, an advocacy for an empiricist stance toward modality.

Vorbereitungslektüre

Background Reading

• Mermin (1981)