Table of Contents

Welcome to the homepage of the research group on Reasoning, Rationality and Science at the Institute for Philosophy II, Ruhr-University Bochum.

Description of the Group

The Reasoning, Rationality and Science Group is coordinated by Dunja Šešelja and Christian Straßer. Dunja is a philosopher of science with special interests in the dynamics and rationality of scientific inquiry, from pursuit-worthiness to information sharing, the division of scientific labor and communicating science (wisely) to the public. Christian is a logician, specialized in formal models of defeasible reasoning (nonmonotonic logic, formal argumentation). They have been collaborating since many years and finally founded this group with the support of the Ruhr University Bochum to join forces and gather enthusiastic researchers around them to investigate the many fascinating questions surrounding reasoning, rationality and science.


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Members and Guests

Current Members


Currently the group hosts the following researchers:

  • Permanent staff
    • Dunja Šešelja (permanent student, aka full professor, Wasserstraße 221, office 4/202)

      dunja.jpg Dunja is working in social epistemology and philosophy of science. She serves as a co-editor in chief of the European Journal for Philosophy of Science. Her research topics include formal modeling of scientific inquiry (with focus on agent-based modeling), scientific disagreements and controversies, pursuit-worthiness of scientific theories, and integrated history and philosophy of science. Find more information on her academia page and her page at TU Eindhoven, where she is employed on 25%.

    • Christian Straßer (permanent student aka full professor, Wasserstraße 221, office 4/401)

      pass2.png Christian is a professor of Logic in Philosophy and Artificial Intelligence at the Institute for Philosophy II at Ruhr University Bochum. He is specialized in non-monotonic logics, defeasible reasoning, argumentation, deontic and adaptive logics. He is interested in utilizing formal methods (such as logical or computational methods) in philosophy. Beyond logic his research interests spread into the philosophy of science and social epistemology. You find more information on him here and his CV here (and a pdf here).

    • Prof. Dr. Dr. Cali (Hoomanologist)

      cali.png The –without doubt– most prominent and cheerful member of the group is the Hoomanologist Cali, specialized for Hooman intelligence and well-known for his books “How to train the hooman. The limitations of the hooman mind.” While working in our group he also got interested in logic, see his latest book “My barks don’t lie. Semantic paradoxes as a trademark of Hooman language.” Yes, we can learn a lot from him …

  • Doctoral- and Post-Doctoral researchers
    • Matteo Michelini (Cotutelle PhD student, TU Eindhoven and Ruhr-University Bochum)

      matteo-michelini.jpg Matteo is a cotutelle PhD student of TU Eindhoven and Ruhr University Bochum. He works with agent-based models in the areas of social epistemology and philosophy of science.
      Matteo is jointly supervised by Dunja and Wybo Houkes.

    • Luca Redondi (PhD, Wasserstraße, office 4/422)

      luca.jpeg Luca has a background in ethics with a focus on Kant and is especially interested in deontic logic. He works on applications of deontic logic and explanation in bioethics within the LoDEx project on Logical Methods for Deontic Explanation.

    • Minkyung Wang (PostDoc, Wasserstraße 221, office 4/403)

      minkyung.jpg Minkyung is a postdoctoral researcher in Logic in Philosophy and ArtificialIntelligence. Her current research focuses on integrating logical and probabilistic reasoning, which is addressed in formal epistemology, social epistemology, and formal argumentation. As a mathematical philosopher, she is keen on using formal methods to solve philosophical problems, particularly those related to epistemology, decision theory, and ethics. Her webpage is here.

    • Eliot Watkins (PostDoc, Wasserstraße, office 4/403)

      eliot.jpg Eliot Watkins joined the research group as a postdoc in 2024 after completing a PhD in Philosophy at MIT. His research focuses on the nature of reasons and the semantics of normative natural language. Examples of some of the more unusual positions defended by Eliot in recent work include the claim that reasons to eat ham sandwiches needn’t be reasons to eat sandwiches, and the claim that there are normative reasons for smoke detectors to behave in some ways and not others. At Bochum, Eliot is working as a part of LoDEX (Logical Methods of Deontic Explanation) — a WEAVE-funded collaboration between Ruhr-University Bochum, TU Vienna and the University of Luxembourg. You can find out more about his research here.

    • Soong Yoo (PhD student, Wasserstraße 221, office 4/423)

      soong-yoo.jpg Should epistemic workers of the world unite? There are some thoughts or decision we would make only when hanging around with friends, colleagues, and strangers. Same for people doing cognitive tasks for their living. Soong is working with agent-based-models in hope to see how computer simulations would predict and suggest a better conveyor belt of knowledge production.
      Soong is jointly supervised by Dunja and Christian.


  • Christiane Dahl (admin, Building GA 04/42, Mondays at Wasserstraße 4/402)

    letterbox_400__trans_18c974cb771c27d50886ec64e546607f_letterbox_650__trans_74c76e999bc593d614f4b18f45adddd4_foto_cd.jpg Christiane is running the offices of Markus Werning, Kristina Liefke, Dunja, and Christian.

Student Staff

  • Jessica Krumus

    jessica.jpg Jessica is a Bachelor student in Philosophy and Biology. She has a special interest in logic and metaphysics. After tutoring for the Logic introductory lecture, she started as a student research assistent for Dunja and Christian.

  • Tom-Felix Berger

    tomfelix.jpg Tom-Felix is a Master’s student in philosophy at the Ruhr University Bochum and a Master’s student in data science at Fernuniversität Hagen. He works as a student assistant for Christian and Dunja and adds content to the LoDEx website. His main research interest is in the evolution of moral thought in humans, which he investigates using formal tools such as agent-based modelling and game theory.


Current Guests

  • Zheng Zhou (Beijing Normal University)

    zheng.jpg Zheng is a PhD student from the School of Philosophy at Beijing Normal University. Since December 2023, he has been conducting a one-year visit in Bochum. Zheng’s interests primarily lie in the application of formal argumentation in normative reasoning and deontic explanation. His email is

Previous guests

  • Ofer Arieli (Professor of Computer Science at the School of Computer Science, The Academic College of Tel-Aviv)

    ofer.jpg visted our group from for one month until the 10th of June 2024

  • Javier Osorio Mancilla, Autonomous University of Madrid: Javier will stay with us from January 15-30. He will give a talk for our MA and PhD students.
  • Ofer Arieli (Tel Aviv) visited us for a week in May 2023.
  • Badran Raddaoui (Wasserstraße 221, office 4/403, Associate Professor, Telecom SudParis, Polytechnic Institute of Paris).

    badran.png Badran is spending his sabbatical as a guest in Bochum.

  • Leon van der Torre (Luxembourg) and Reka Markovich (Luxembourg) visited us for a week in March 2023.
  • Martin Justin (Master Student, University of Ljubljana)

    martin-justin.jpg Martin is a master’s student of philosophy at University of Ljubljana. As an exchange student at RUB, he is working with Dunja on his thesis about disagreement in scientific communities.

Previous Staff

Previous PostDocs

  • Kees van Berkel (Assistant Prof. TU Vienna)

    kees.png Kees is a PostDoc in the Reasoning, Rationality & Science group. You find his webpage here. He works on logical methods for normative reasoning. This includes methods from modal logic, nonmotonic logic, proof theory, and formal argumentation. He is working together with Christian on formal explanation of reasoning with normative systems. Kees is furthermore interested in the metaethical principle of `ought implies can’ (both from a philosophical and logical point of view), and the philosophy of practical reasoning.

Previous Student Staff

  • Lisa Michajlova

    lisa.jpg Lisa is now finishing her Bachelor of Science in Mathematics with minor in Philosophy. She currently works as a student assistant with Christian on Probabilistic Argumentation theory. She studies the Probabilistic Framework by Haenni and investigates argument strength defined for example by Pfeifer. Lisa loves playing sports including table tennis and chess.

Associate Members

  • Daniel Frey (Currenta, Leverkusen)

    s200_daniel.frey.jpg Daniel frequently collaborates with us on agent-based models. He is equally interested in the implementation side of things (e.g., NetLogo) and the conceptual considerations underlying formal models. His master thesis offers an investigation into Kevin Zollman’s notion of transient diversity.

  • Badran Raddaoui (Associate Professor, Telecom SudParis, Polytechnic Institute of Paris)

    badran.png Badran Raddaoui is an associate professor of computer science at the Polytechnic Institute of Paris. His research interests include reasoning under inconsistency and uncertainty, formal models of argumentation, satisfiability and constraints programming. Further topics that he is interested in concerns the application of symbolic AI techniques for data and graph mining.



Presenters in bold font.


  • Minkyung presented on the The Utility Theory of Cogent Belief at NEW II, Northeastern University, Boston.
  • Christian presented at the LUCI research colloquium (University Milan) on Reasoning and Explaining with Norms and Defaults (joint work with Ofer Arieli, Kees van Berkel and Zheng Zhou).


  • Kees presented on Towards Deontic Explanations in Formal Argumentation (joint work with Christian) at the NOREA workshop in Leuven
  • Christian presented a keynote Towards Deontic Explanation: an Argumentative Proof Calculus for the workshop “Reasoning with Imperfect Information in Social Settings”
  • 30-31st of March: Will Fleisher (Georgetown), Dan Friedman (Stanford), and Dunja Šešelja,
    “Towards epistemically responsible fact-checking of scientific claims” at the Workshop “(Mis)Interpretation of scientific evidence”
  • 16th of March: Will Fleisher (Georgetown), Dan Friedman (Stanford), and Dunja Šešelja,
    “Towards epistemically responsible fact-checking of scientific claims” at the University of Twente Philosophy Speakers Series
  • 8th of March: Will Fleisher (Georgetown), Dan Friedman (Stanford), and Dunja Šešelja,
    “Towards epistemically responsible fact-checking of scientific claims” at the Centre for Science Studies at Aarhus University
  • 22nd of February: Wybo Houkes, Matteo Michelini, Javier Osorio, Dunja Šešelja, and Christian Straßer,
    “How Scientists Can Benefit from Disagreements” at Workshop on Agent-Based Models of Epistemic Communities



  • Louise Dupuis de Tarlé, Matteo Michelini, AnneMarie Borg, Gabriella Pigozzi, Juliette Rouchier, Dunja Šešelja, Christian Straßer,
    An Agent-Based Model of MySide Bias in Scientific Debates,
    Forthcoming in JASSS.
  • Said Jabbour, Badran Raddaoui, Christian Straßer,
    Towards a Principle-based Framework for Assessing the Contribution of Formulas on the Conflicts of Knowledge Bases,
    , Forthcoming IJCAI 2024.
  • Ofer Arieli, Kees van Berkel, Christian Straßer,
    Defeasible Normative Reasoning: A Proof-Theoretic Integration of Logical Argumentation,
    Forthcoming, AAAI 2024.


  • Kees van Berkel, Reka Markovich, Christian Straßer, Leon van der Torre,
    Arguing About Choosing a Normative System: Conflict of Laws,
    Legal Knowledge and Information Systems (JURIX 2023), p. 73–82, 2023
  • Dunja Šešelja,
    Agent-based modeling in the philosophy of science,
    forthcoming in the Stanford Encyclopedia of Philosophy
  • Ofer Arieli, AnneMarie Borg and Christian Straßer,
    A Postulate-Driven Study of Logical Argumentation,
    conditionally accepted for Artificial Intelligence Journal
  • Daniel Cserhalmi Friedman and Dunja Šešelja,
    Scientific Disagreements, Fast Science and Higher-Order Evidence,
    accepted for Philosophy of Science
  • Said Jabbour, Badran Raddaoui and Christian Straßer,
    A Comparative Study of Ranking Formulas based on Consistency,
    accepted for publication in IJCAI 2023 (15% acceptance rate)
  • Jesse Heyninck, Badran Raddaoui and Christian Straßer,
    Ranking-based Argumentation Semantics applied to Logical Argumentation,
    accepted for publication in IJCAI 2023 (15% acceptance rate)
  • Matteo Michelini, Javier Osorio, Wybo Houkes, Dunja Šešelja, and Christian Straßer,
    “Scientific disagreements and the diagnosticity of evidence: how too much data may lead to polarization”,
    accepted for publication in JASSS (Journal of Artificial Societies and Social Simulation), 2023.
  • Christian Straßer and Lisa Michajlova,
    “Evaluating and Selecting Arguments in the Context of Higher Order Uncertainty” accepted for publication in Frontiers of Artificial Intelligence

Workshops and Conferences