Synergy and Disagreement

Marc Andree Weber (Universität Mannheim, University of Heidelberg)

The Senior Professorship for Theoretical Philosophy at Heinrich Heine University kindly invites you to attend the talk by Marc Andree Weber within the Research Colloquium, from 6:30pm to 8pm (CET) on May 20, 2025.

Abstract: Synergy effects are taken to occur if equally well-informed and competent people agree, or nearly agree, that a certain proposition is true (or that it is false); these people should then take their agreement as confirmation that their reasoning has been correct and adopt an even greater (or lower) credence towards the issue under debate. Thus understood, synergy effects appear to occur quite frequently. In my talk, I will argue that a necessary condition for synergy effects to occur is that we cannot take our evidence at face value. This might happen either because we should be epistemically cautious in cases of presumed asymmetrical proneness to error (cases in which the relevant evidence supports either credence 1 or credence 0 towards the proposition at issue are the prime examples hereof); or because background information rules out the option supported by our remaining evidence. This result preserves the intuitive appeal of considerations on synergy but significantly restricts their scope. It thereby also reconciles considerations on synergy with a natural interpretation of conciliatory views on peer disagreement.

Speaker: Marc Andree Weber is an Academic Staff Member at the Chair of Theoretical Philosophy/Philosophy of Language at the University of Mannheim. Since October 2021, he is doing research on the ethics of belief within the DFG-funded project The Moral Dimension of Doxastic Norms. In 2022 and 2023, he was interim professor for theoretical philosophy, first at Heidelberg University and then at Hamburg University. From 2017 to 2018, he worked as an Assistant Professor at the Chair of Epistemology and Theory of Science at the University College Freiburg. Before that, he was a member of the interdisciplinary research projects “Dealing Reasonably with Blurred Boundaries” and “Deep Disagreements”. Marc Andree Weber studied Mathematics and Philosophy in Heidelberg and Melbourne. He earned his PhD in 2011 with a thesis on the transtemporal identity of persons. In 2019, he completed his habilitation with a thesis on the epistemic significance of disagreement. Recent relevant publications include: (2014). Die Zerlegung des Ichs. Über die Grundlagen personaler Identität. Münster: Mentis; (2019) Meinungsverschiedenheiten. Eine erkenntnistheoretische Analyse. Frankfurt a.M.: Klostermann (Philosophische Abhandlungen, Bd. 118); (2024) The Astute and the Kindly Ones. Epistemological Remarks on Disagreements in Politics and Law. Grazer Philosophische Studien 101.1, 1–27 and (2024) An Argument for Moral Evidentialism. Theoria 90.6, 583–602.

Marc Andree Weber's talk will be held in a hybrid format: in person in Room 24.53 01.81 and with the option to join via Zoom. For the Zoom link, please email [email protected]. We look forward to your participation.