PD Dr. Gordian Haas

Research Fellow
Fon: +49 (0)30 31805472

Gordian Haas is a habilitated philosopher who wrote his doctoral thesis on rational belief-forming processes. His areas of specialization include the philosophy of science in general and the analysis of democratic decision-making procedures and criteria of scientific significance in particular. His research is characterized by the application of formal methods.

Gordian Haas has over 20 years of teaching experience and has authored two monographs and numerous scientific publications in leading journals. Among other positions, he has worked as a Akademischer Oberrat (senior academic councillor) and as a deputy professor at various German universities and was a Humboldt Fellow at U.C. Berkeley.

Since 2019, Gordian Haas has been working as an expert for the European Commission and regularly evaluates projects in the field of education and research.

Gordian Haas joined the nexus institute in 2021 and is primarily involved in the field of deliberative democracy at the intersection between politics, society, and science.

Publications (selection)


Haas, Gordian: Minimal Verificationism: On the Limits of Knowledge. Berlin/Boston: De Gruyter 2015 (= Epistemische Studien Vol. 31. Ed. M. Esfeld, S. Hartmann, A. Newen)

Haas, Gordian: Revision und Rechtfertigung: Eine Theorie der Theorieänderung. Heidelberg: Synchron 2005. (= Philosophische Impulse Vol. 5. Ed. F. Mühlhölzer, W. Spohn)


Haas, Gordian: JuDAS: A Theory of Rational Belief Revision. In: Synthese 2018. DOI 10.1007/s11229-018-01958-0.

Haas, Gordian: Four Ways in which Theories of Belief Revision Could Benefit from Theories of Epistemic Justification. In: Erkenntnis 2018. DOI 10.1007/s10670-018-0028-2.

Haas, Gordian: Formale Repräsentation von Überzeugungen und Theorien der Überzeugungsrevision. In: M. Grajner, G. Melchior (Hrsg.) Handbuch Erkenntnistheorie. Springer 2018.

Haas, Gordian: A Brief Remark on Non-prioritized Belief Change and the Monotony Postulate. In: Acta Analytica Vol. 31 (2016) Issue 3.

Haas, Gordian: Argumentationstheoretische Betrachtungen zum „Ackermann“. In: Zeitschrift für Germanistik Vol. 26 (2016) Issue 1.

Haas, Gordian: Epistemic Accessibility as a New Criterion of Significance. In: W. Freitag, H. Rott, H. Sturm et. al. (Hrsg.) Von Rang und Namen: Essays in Honour of Wolfgang Spohn. Münster: Mentis 2016.

Haas, Gordian: Some Remarks on the Definition of Lehrer’s Ultrasystem. In: E.J. Olsson (Hrsg.) The Epistemology of Keith Lehrer. Philosophical Studies Series 95. Dordrecht: Springer 2003.