Marion Vorms

Senior lecturer (maîtresse de conférences) in philosophy of science at University Paris 1 Panthéon-Sorbonne, permanently affiliated at IHPST (Institute for the history and philosophy of science and technology, CNRS).

Leader of the IHPST's Decision, Reasoning, and Uncertainty research team.


Junior member of Institut universitaire de France.


Honorary research fellow at the University College Division of Psychology and Languages Sciences

Associate research fellow at the Centre de recherche sur la justice et le règlement des conflits (legal studies, University of Paris 2 Panthéon-Assas).

Formerly affiliated research scholar at Cambridge History and Philosophy of Science department


Member of the Scientific Advisory Board of the French National Public Health Agency (Santé Publique France).


Alumna of the École normale supérieure de la rue d'Ulm, agrégée in philosophy.


Download full CV here.

I am a philosopher of science with interdisciplinary interests and methods. Since my PhD in philosophy (Paris 1, 2009), I have acquired postdoctoral training in cognitive and experimental psychology (UCL, 2011-2012, Birkbeck, 2015-2018) and completed a Master 2 in law (Paris 2, 2022).

My research lies at the intersection of the philosophy of science, the psychology of reasoning, and law. Its overarching and unifying theme is evidential reasoning - how people deal with heterogeneous, incomplete and uncertain evidence when searching for answers to factual questions, most often in view of a decision.

My current projects revolve around three main themes.

First, I am interested in evidential reasoning in the legal context. I approach this question from the triple perspective of the philosophy of science (e.g. this involves comparing issues of confirmation and standards of proof in the empirical sciences with what happens in court, as well as revisiting aspects of the epistemology of testimony in the light of testimonial evidence - see paper in progress here), the law (I study how different procedural constraints affect the reasoning of judges and jurors), and the psychology of reasoning (this involves experimentally testing different hypotheses about the inferential processes involved in reasoning about evidence).

Drawing on my Master 2 thesis in law, I am currently writing a book on French evidence law (Droit de la preuve), of which I propose a critical analysis through an epistemological and comparative perspective. See the book's extended synopsis in English here, and read more on my ongoing work on evidential reasoning in law here.

The second major issue I am concerned with is the status and role of scientific expertise in public and individual decision-making: how can and should scientists communicate the irreducibly uncertain conclusions that can be drawn from the current state of research? What standards of proof should govern their responsibility to make claims (and to what extent does this depend on what is at stake in subsequent decisions)? How can they be useful and relevant without being paternalistic? How do they inform without prescribing? I have given a series of talks about these topics (see talks).

Throughout these last two years, I have carried out an in-depth inquiry into the role of scientific information in a French public health trial, the Mediator case. Read more on this case and my ongoing work on it here.

Finally, the most abstract part of my work is devoted to the study of beliefs - their formation and dynamics; here I combine classical philosophical analysis (on doubt, belief change, but also on the evidential role of testimony) and psychological experiments. In particular, I seek to challenge ideas about cognitive biases that are widely accepted but whose empirical basis is highly controversial. Read more on my ongoing experimental projects here.