talks

:: 2024

Geometrizing Inference: The Use of Diagrams in Scholastic Logic. Invited talk at the conference 'Surveying the Realm of Medieval Geometry (XII-XV c.)', Florence (Italy), October 9 - 11, 2024.
The Region Connection Calculus, Euler Diagrams and Aristotelian Diagrams (joint work with Claudia Anger). Poster presentation at Diagrams 2024: the 14th International Conference on the Theory and Application of Diagrams, Münster (Germany), September 27 - August 1, 2024.
Category Theory for Aristotelian Diagrams: The Debate on Singular Propositions (joint work with Alexander De Klerck and Leander Vignero; talk delivered by Alexander De Klerck). Diagrams 2024: the 14th International Conference on the Theory and Application of Diagrams, Münster (Germany), September 27 - August 1, 2024.
Euler Diagrams, Aristotelian Diagrams and Syllogistics (joint work with Hans Smessaert). Diagrams 2024: the 14th International Conference on the Theory and Application of Diagrams, Münster (Germany), September 27 - August 1, 2024.
Alpha-Structures and Ladders in Logical Geometry (joint work with Alexander De Klerck; talk delivered by Alexander De Klerck). Square 2024: the 8th World Congress on the Square of Opposition, San José (Costa Rica), September 9 - 13, 2024.
"Must" People Reason Logically with "Permission" in Daily Situations? An Explorative Experimental Investigation in Human Reasoning of Normative Concepts (joint work with Wai Wong, Meimei Yang, Walter Schaeken and Joost Vennekens; talk delivered by Wai Wong). CogSci 2024: the 46th Annual Meeting of the Cognitive Science Society, Rotterdam (the Netherlands), July 24 - 27, 2024.

:: 2023

The Logical Geometry of the Region Connection Calculus. Research seminar of the Center for Logic and Philosophy of Science (CLPS), Leuven (Belgium), December 15, 2023.
Diagrammatic Innovations in Louvain Logic Notebooks. LECTIO XII Annual Conference: Innovationes Lovanienses, Leuven (Belgium), December 6 - 8, 2023.
STARTDIALOG: Towards a Systematic Theory of Aristotelian Diagrams in Logic. Logica Universalis Webinar series, online, November 15, 2023.
First-Order Logic, Quarc, and the Logical Geometry of Existential Import. ECAP 11: the 11th European Congress of Analytic Philosophy, Vienna (Austria), August 21 - 25, 2023.
The Logical Geometry of the Region Connection Calculus. Second Syllogism and Argumentation workshop, Santiago (Chile)/virtual, July 28, 2023.
Categories of Aristotelian Diagrams (joint work with Alexander De Klerck and Leander Vignero; talk presented by Alexander De Klerck). 17th Congress of Logic, Methodology and Philosophy of Science and Technology (CLMPST), Buenos Aires (Argentina), July 24 - 29, 2023.
Aristotelian Diagrams from Ancient Logic to Artificial Intelligence. Research seminar of the Laboratoire SPHère (CNRS UMR 7219), Paris (France), April 21, 2023. (Postponed due to personal circumstances.)
The Algebra of Aristotelian Diagrams. Antwerp Algebra Colloquium, Antwerp (Belgium), March 24, 2023.
From Euler Diagrams to Aristotelian Diagrams. World Logic Day celebration, Santiago (Chile) - Puebla (Mexico) - online, January 13, 2023.

:: 2022

From Aristotelian Diagrams to Logical Geometry. Inaugural lecture as research professor of logic, Institute of Philosophy, Leuven (Belgium), November 10, 2022.
Leonardi.DB: A Database of Aristotelian Diagrams. Logica Universalis Webinar series, online, October 19, 2022.
Deontic DMN: Representing Deontic Statements in DMN with Bitstring Semantics (joint work with Wai Wong, Joost Vennekens and Walter Schaeken; talk presented by Wai Wong). DecisionCamp 2022: Business Rules and Decision Management Technologies, Berlin (Germany)/virtual, September 26 - 28, 2022.
How do Humans Reason With and Between' Obligatory' and 'Permitted'? An Experimental Study of the Relationship Between Deontic Terms (joint work with Wai Wong, Joost Vennekens and Walter Schaeken; poster presented by Wai Wong). XPRAG 2022: the 9th Experimental Pragmatics Conference, Pavia (Italy), September 22 - 23, 2022.
From Aristotelian Diagrams to Logical Geometry. Invited inspirational talk at the Graduate Symposium of Diagrams 2022: the 13th International Conference on the Theory and Application of Diagrams, Rome (Italy), September 17, 2022.
Aspect Shifting in Aristotelian Diagrams (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Diagrams 2022: the 13th International Conference on the Theory and Application of Diagrams, Rome (Italy), September 14 - 16, 2022.
From Euler Diagrams to Aristotelian Diagrams (joint work with Hans Smessaert). Diagrams 2022: the 13th International Conference on the Theory and Application of Diagrams, Rome (Italy), September 14 - 16, 2022.
A Database of Aristotelian Diagrams: Empirical Foundations for Logical Geometry (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Diagrams 2022: the 13th International Conference on the Theory and Application of Diagrams, Rome (Italy), September 14 - 16, 2022.
Two Perspectives on Existential Import. Square 2022: the 7th World Congress on the Square of Opposition, Leuven (Belgium), September 9 - 13, 2022.
On the Ubiquity of Symmetry in Logical Geometry (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Symmetry 2022: the 12th SIS-Symmetry Congress, Porto (Portugal), July 11 - 17, 2022.

From Existential Import in Syllogistics to Translations between Modal Logics. Invited talk at the Syllogism and Argumentation workshop, Santiago (Chile)/virtual, June 23, 2022.

:: 2021

On the Cognitive Potential of Derivative Meaning in Aristotelian Diagrams (joint work with Hans Smessaert and Atsushi Shimojima; talk delivered by Hans Smessaert). Diagrams 2021: the 12th International Conference on the Theory and Application of Diagrams, online, September 28 - 30, 2021. (Virtual conference due to the Covid-19 pandemic.)
Schopenhauer's Partition Diagrams and Logical Geometry (joint work with Jens Lemanski; talk delivered by Jens Lemanski). Diagrams 2021: the 12th International Conference on the Theory and Application of Diagrams, online, September 28 - 30, 2021. (Virtual conference due to the Covid-19 pandemic.)
Extending Knowledge Space Theory to Contingent Information with Bitstring Semantics (joint work with Wai Wong, Walter Schaeken and Joost Vennekens; talk delivered by Wai Wong). MathPsych/ICCM 2021: Annual Joint Meeting of the Society for Mathematical Psychology and the International Conference on Cognitive Modeling, July 1 - 12, 2021. (Virtual conference due to the Covid-19 pandemic.)
The Modal Logic of John Fabri of Valenciennes (fl. c. 1500) (joint work with Christophe Geudens; talk delivered by Christophe Geudens). Workshop: How to Investigate Student Notes from the Renaissance (ca. 1300-1600)?, Leuven (Belgium), May 20 - 21 and 27 - 28, 2021.
Boolean Considerations on John Buridan's Octagons of Oppositions, Medieval Logic and Ontology (MeLO) seminar, Leuven (Belgium), March 26, 2021. (Virtual seminar due to the Covid-19 pandemic.)
Aristotelische diagrammen: eeuwenoud, springlevend [Aristotelian diagrams: centuries old, alive and kicking. The state of affairs in logical geometry], Lessen voor de eenentwintigste eeuw 2021 (studium generale program), Leuven (Belgium), March 8, 2021.

:: 2020

.Using Multigraphs to Study the Interaction between Opposition, Implication and Duality Relations in Logical Squares (joint work with Hans Smessaert). Diagrams 2020: the 11th International Conference on the Theory and Application of Diagrams, Talinn (Estonia), August 24 - 28, 2020. (Virtual conference due to the Covid-19 pandemic.)

Free Rides in Logical Space Diagrams versus Aristotelian Diagrams (joint work with Hans Smessaert and Atsushi Shimojima). Diagrams 2020: the 11th International Conference on the Theory and Application of Diagrams, Talinn (Estonia), August 24 - 28, 2020. (Virtual conference due to the Covid-19 pandemic.) [Best Paper Award at Diagrams 2020!]
The Logical Geometry of Knowability. Fifth CLPS/DWMC Symposium on Analytic and Medieval Philosophy, Leuven (Belgium), May 29, 2020. (Event postponed due to the Covid-19 pandemic.)

:: 2019

Logical Geometry and Probability. Brown bag talk at the Center for Logic and Philosophy of Science (CLPS), Leuven (Belgium), October 11, 2019.

:: 2018

A Guided Tour of Logical Geometry, Based on the Keynes-Johnson Octagon. Invited keynote talk at Square 2018: the 6th World Congress on the Square of Opposition, Crete (Greece), November 1 - 5, 2018.
The Interplay between Aristotelian and Duality Relations in Four Octagons of Opposition (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Square 2018: the 6th World Congress on the Square of Opposition, Crete (Greece), November 1 - 5, 2018.
Aristotelian Diagrams for the Proportional Quantifier 'Most' (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Square 2018: the 6th World Congress on the Square of Opposition, Crete (Greece), November 1 - 5, 2018.
Ordering Relations, Partitions and Aristotelian Diagrams (joint work with Hans Smessaert). Logic Now and Then 4 (LNAT4), Brussels (Belgium), September 20, 2018.
Writing and Drawing in Logic - The Case of Aristotelian Diagrams. Workshop on Practices of Writing and Reading in Logic, affiliated workshop of UNILOG 2018, Vichy (France), June 23 - 24, 2018.
Towards a Typology of Diagrams in Linguistics (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Diagrams 2018: the 10th International Conference on the Theory and Application of Diagrams, Edinburgh (UK), June 18 - 22, 2018.
Aristotelian and Duality Relations Beyond the Square of Opposition (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Diagrams 2018: the 10th International Conference on the Theory and Application of Diagrams, Edinburgh (UK), June 18 - 22, 2018.
Response to Nicolas Zaks, Plato on the Semantics of Negation in the Sophist (257b-c). Fourth CLPS/DWMC Symposium on Analytic and Medieval Philosophy, Leuven (Belgium), June 4, 2018.
The Role of Aristotelian Diagrams in Scientific Communication. 8th Visual Learning Conference, Budapest (Hungary), April 26 - 28, 2018.
Aristotelian Diagrams: the Forgotten Icons of Logic (joint work with Hans Smessaert). Workshop on Scholarly Forgetting in the Humanities, Helmstedt (Germany), April 19 - 21, 2018.
Response to Catarina Dutilh Novaes, Metaphors for Argumentation: A Social-Epistemological Approach. Thursday Lectures, Leuven (Belgium), March 1, 2018.

:: 2017

The Logical Geometry of Russell's Theory of Definite Descriptions. Poster presentation at the Fourth Philosophy of Language and Mind Conference (PLM4), Bochum (Germany), September 21 - 23, 2017.
The Logical Geometry of Russell's Theory of Definite Descriptions. Research Colloquium 'Logic and Epistemology' of the Institut für Philosophie II, Bochum (Germany), July 13, 2017.
Duality and Lexicalization in Medieval Squares of Opposition. Third CLAW/DWMC Symposium on Analytic and Medieval Philosophy, Leuven (Belgium), May 31, 2017.

:: 2016

The Logical Geometry of Russell's Theory of Definite Descriptions. Research Seminar of the Center for Logic and Analytical Philosophy (CLAW), Leuven (Belgium), November 15, 2016.
The Interaction between Logic and Geometry in Aristotelian Diagrams (joint work with Hans Smessaert). Diagrams 2016: the 9th International Conference on the Theory and Application of Diagrams, Philadelphia, PA (United States), August 7 - 10, 2016.
Visualising the Boolean Algebra B_4 in 3D (joint work with Hans Smessaert). Poster presentation at Diagrams 2016: the 9th International Conference on the Theory and Application of Diagrams, Philadelphia, PA (United States), August 7 - 10, 2016.
The Continuity between Logic and Metalogic from the Perspective of Logical Geometry. Workshop 'Language and Metalanguage, Logic and Metalogic - Revisiting Tarski's Hierarchy', Louvain-la-Neuve (Belgium), May 19 - 20, 2016.
Response to Mingyu Ma, Supposition and Reference. Second CLAW/DWMC Symposium on Analytic and Medieval Philosophy, Leuven (Belgium), April 22, 2016.

:: 2015

Interactively Illustrating the Context-Sensitivity of Aristotelian Diagrams. Ninth International and Interdisciplinary Conference on Modeling and Using Context (CONTEXT 2015), Larnaca (Cyprus), November 2 - 6, 2015.
Shape Heuristics in Aristotelian Diagrams (joint work with Hans Smessaert). SHAPES 3.0, Larnaca (Cyprus), November 2, 2015.
Aristotelian Diagrams for Multi-Operator Formulas in Avicenna and Buridan (joint work with Hans Smessaert). 15th Congress of Logic, Methodology and Philosophy of Science (CLMPS), Helsinki (Finland), August 3 - 8, 2015.
Metalogical Decorations of Logical Diagrams (joint work with Hans Smessaert). 15th Congress of Logic, Methodology and Philosophy of Science (CLMPS), Helsinki (Finland), August 3 - 8, 2015.
Response to Luca Gili, Thomas Aquinas on Future Contingents. First CLAW/DWMC Symposium on Analytic and Medieval Philosophy, Leuven (Belgium), May 22, 2015.
Buridan's and Avicenna's Aristotelian Diagrams for Combined Operators. First CLAW/DWMC Symposium on Analytic and Medieval Philosophy, Leuven (Belgium), May 22, 2015.
One-Sided versus Two-Sided Readings of Many and Few (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Logic Now and Then 3 (LNAT3), Brussels (Belgium), February 5, 2015

:: 2014

A Unified Account of Aristotelian and Hasse Diagrams. Fourth Young Researchers Days in Logic, Philosophy and History of Science (YRD 4), Brussels (Belgium), September 26 - 27, 2014.
Logical and Geometrical Complementarities between Aristotelian Diagrams (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Diagrams 2014: the 8th International Conference on the Theory and Application of Diagrams, Melbourne (Australia), July 28 - August 1, 2014.
The Relationship between Aristotelian and Hasse Diagrams (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Diagrams 2014: the 8th International Conference on the Theory and Application of Diagrams, Melbourne (Australia), July 28 - August 1, 2014.
Logical Geometries and Information in the Square of Oppositions and its Extensions. Square 2014: the 4th World Congress on the Square of Opposition, Rome/Vatican (Italy), May 5 - 9, 2014.
Algebraic and Cognitive Aspects of Presenting Aristotelian Diagrams (joint work with Hans Smessaert). Square 2014: the 4th World Congress on the Square of Opposition, Rome/Vatican (Italy), May 5 - 9, 2014.
The Unreasonable Effectiveness of Bitstrings in Logical Geometry (joint work with Hans Smessaert; talk delivered by Hans Smessaert). Square 2014: the 4th World Congress on the Square of Opposition, Rome/Vatican (Italy), May 5 - 9, 2014.
A Unified Account of Aristotelian and Hasse Diagrams. Fourth Philosophy Graduate Conference, Leuven (Belgium), March 28, 2014.
Logical Geometry: Platonic Representations of Aristotelian Logic. Common Seminar of the Institute of Philosophy (HIW), Leuven (Belgium), March 26, 2014.
The Dynamics of Surprise. Poster presentation at the second Day on Research in the Humanities and Social Sciences, Leuven (Belgium), March 12, 2014.

:: 2013

Neighborhood Semantics for Public Announcement Logic. Congress on Logic and Philosophy of Science (CLPS 13), Ghent (Belgium), September 16 - 18, 2013.
Weak and Strong Interpretations of the Dynamic Turn in Epistemic Logic. Third Philosophy Graduate Conference, Leuven (Belgium), March 22, 2013.

:: 2012

The Role of Information in Logical Geometry (joint work with Hans Smessaert). Research Seminar of the Center for Logic and Analytical Philosophy (CLAW), Leuven (Belgium), November 23, 2012.
Surprise in Probabilistic Dynamic Epistemic Logic. Logic and Interactive Rationality (LIRA) Workshop, ILLC, Amsterdam (the Netherlands), October 4, 2012.
Surprise in Probabilistic Dynamic Epistemic Logic. Conference of the Reasoning Club, Brussels (Belgium), September 17 - 19, 2012.
Logical Omniscience and Structured Propositions. Third Young Researchers Days in Logic, Philosophy and History of Science (YRD 3), Brussels (Belgium), September 3 - 4, 2012.
Algebraic Aspects of Duality Diagrams. Poster presentation at Diagrams 2012: the 7th International Conference on the Theory and Application of Diagrams, Canterbury (UK), July 2 - 6, 2012.
Surprise in Probabilistic DEL. 10th Conference on Logic and the Foundations of Game and Decision Theory (LOFT 2012), Sevilla (Spain), June 18 - 20, 2012.
The Role of Information in Logical Geometry (joint work with Hans Smessaert). Informal workshop of the research groups on logical geometry and n-opposition theory, Leuven (Belgium), June 11, 2012.
Information in the Square of Oppositions (joint work with Hans Smessaert). Trends in Logic XI, Bochum (Germany), June 3 - 5, 2012.
The Dynamics of Surprise. Modal Logic workshop, Brussels (Belgium), May 8, 2012.
A Brief Overview of Logical Geometry. PhDs in Logic IV, Ghent (Belgium), April 12 - 13, 2012.
Reduction Axioms in Dynamic Logics of Agency. Second Philosophy Graduate Conference, Leuven (Belgium), March 23, 2012.

:: 2011

Group Theory and Duality Diagrams. Logic Now and Then 2 (LNAT 2), Brussels (Belgium), December 21 - 22, 2011.
Logical Geometry: What, How, and Why? Informal workshop of the research groups on logical geometry and n-opposition theory, Leuven (Belgium), November 11 - 12, 2011.
An Algebraic Perspective on Duality in Logic and Language. Poster presentation at the first Day on Research in the Humanities and Social Sciences, Leuven (Belgium), November 10, 2011.
An Algebraic Perspective on Duality in Logic and Language. Poster presentation at Semantics and Philosophy in Europe 4 (SPE 4), Bochum (Germany), September 26 - October 1, 2011.
Structures of Oppositions in Public Announcement Logic. And: Some Algebraic Remarks on Duality. Symposium on the Logic of Opposition (affiliated symposium of CLMPS 14), Nancy (France), July 19 - 26, 2011.
Neighborhood Semantics for Dynamic Epistemic Logics. 14th Congress of Logic, Methodology and Philosophy of Science (CLMPS), Nancy (France), July 19 - 26, 2011.
The Dynamic Turn in Epistemic Logic: A Philosophical Perspective. First Philosophy Graduate Conference, Leuven (Belgium), April 1, 2011.
Epistemic Dynamics and Logical Omniscience. Research Seminar in Logic and Language, TiLPS, Tilburg (the Netherlands), March 10, 2011.
Epistemic Dynamics and Logical Omniscience. Research Seminar of the Center for Logic and Analytical Philosophy (CLAW), Leuven (Belgium), March 9, 2011.

:: 2010

The Use of Corpus Linguistics in the Philosophy of Mathematical Practice (joint work with Benedikt Löwe and Bernhard Schröder). First International Meeting of the Association for the Philosophy of Mathematical Practice (APMP), Brussels (Belgium), December 9 - 11, 2010.
Narrative and Information. Logical and Philosophical Comments on Benedikt Löwe's 'Formal Models of Narrative'. Third Workshop in the Philosophy of Information, Brussels (Belgium), November 18 - 19, 2010.
Agreeing to Disagree in Probabilistic Dynamic Epistemic Logic. Research Seminar in Logic and Language, TiLPS, Tilburg (the Netherlands), October 28, 2010.
Contemporary Epistemic-Doxastic Logic and the Lockean Thesis. Logic, Reasoning and Rationality (LRR 10), Ghent (Belgium), September 20 - 22, 2010.
Looking for the Right Notion of Epistemic Plausibility Model. Second Young Researchers Days & Workshop on Logic, Philosophy and History of Science (YRD 2), Brussels (Belgium), September 6 - 7, 2010.
Some Remarks on the Model Theory of Epistemic Plausibility Models. 9th Conference on Logic and the Foundations of Game and Decision Theory (LOFT 2010), Toulouse (France), July 5 - 7, 2010.
Reversed Squares of Opposition in PAL and DEL. Square 2010: the 2nd World Congress on the Square of Opposition, Corte (France), June 17 - 20.
Formalizing Dynamic Probabilistic Agreement Theorems. Research Seminar of the Formal Epistemology Project (FEP), Leuven (Belgium), June 1, 2010.
Agreeing to Disagree in Probabilistic DEL. Logic and Interactive Rationality (LIRA) Workshop, ILLC, Amsterdam (the Netherlands), April 12, 2010.
Towards a Dynamics of Realistic Knowledge: Neighborhood Semantics for Public Announcement Logic. VAF IV: Fourth Conference of the Dutch-Flemish Association for Analytic Philosophy, Leuven (Belgium), January 20 - 22, 2010.

:: 2009

''It is easy to see that...'' A corpus study of mathematical proof. Logic Tea Colloquium, ILLC, Amsterdam (the Netherlands), April 21, 2009.