On February 5, 2026, we were honored to welcome Nicola Guarino, one of the most prominent figures in the field of applied ontology, as the keynote speaker at the First Swiss Colloquium on Applied Ontology (SCAO 2026), SCOR’s flagship event. His keynote lecture addressed the philosophical notion of truthmaking from the perspective of applied ontology and was followed by an interactive question-and-answer session.
The abstract, a recording of the lecture (excluding the Q&A session), and the slides are available below. To receive updates on upcoming SCOR-related events, readers are invited to subscribe to our newsletter at the bottom of the homepage and/or follow SCOR on LinkedIn.
Nicola Guarino (retired Research Associate, ISTC-CNR; former Director of LOA)
“Truthmakers and Explanation”
Abstract
According to so-called truthmaker essentialism, which seems to be the dominant view, the truthmaker of a proposition is something whose very existence entails the truth of the proposition. There are various positions concerning the ontological nature of such truthmakers, but typically the truthmaker of a necessary proposition like “x is a person” would be x itself, while the truthmaker of a contingent proposition like “x is red” would be either the fact that x is red, or a particular redness trope (or event) involving x. Under this view, truthmaking simply establishes a correspondence between propositions and entities in our ontology. Especially for contingent propositions, this mechanism, however, is rather opaque concerning the specific aspects, belonging to the very nature of x, that are responsible for the truth of such propositions. In short, this view of truthmaking (which we shall label strong truthmaking) appears to have a limited explanatory value.
There is however a non-orthodox position, proposed by Josh Parsons, which rejects truthmaker essentialism, and assumes that it is not the mere existence of the truthmaker that is responsible for the truth of the proposition, but rather the way the truthmaker intrinsically is. Let us call this view weak truthmaking. Under this view, truthmaking depends not so much on whether something exists, but on how something is in itself, independently of anything else. In this sense, weak truthmaking appears to be more informative than strong truthmaking, and in the past it has proved indeed to be extremely useful in conceptual modelling. In particular, under this view an individual quality, like the color of a rose, can be seen as the minimal weak truthmaker of a proposition stating that such rose is red: it is because of its color (and not, say, its smell) that the rose is red.
In this talk I will discuss the technical details of Parsons’ notion of truthmaking, proposing a way to address some of its limits in the light of concrete applications in conceptual modelling.
I will conclude with some practical examples showing how the explanatory power of a conceptual model can be improved by making its truthmakers explicit.
Short bio
Nicola Guarino is a retired research associate at the Institute of Cognitive Sciences and Technologies of the Italian National Research Council (ISTC-CNR), and former director of the ISTC-CNR Laboratory for Applied Ontology (LOA) based in Trento. He has been playing a leading role in the ontology field, developing a strongly interdisciplinary approach that combines Computer Science, Philosophy, and Linguistics. Among the most well known results of his lab, the OntoClean methodology and the DOLCE foundational ontology. He has been founder and co-editor-in-chief of the Applied Ontology journal, founder and former president of the International Association for Ontology and its Applications (IAOA), and editorial board member of International Journal of Semantic Web and Information Systems and Journal of Data Semantics. He is also an ER fellow and a fellow of the European Association for Artificial Intelligence (EurAI). Recently he received the Peter P. Chen award for outstanding contributions to the field of conceptual modeling.
On the theoretical side, his current research interests are focusing on the ontological foundations of knowledge representation and conceptual modeling and specifically the ontology of events, processes, and relationships, while on the application side he has been focusing on enterprise modeling, ontology of economics, and manufacturing. He is also interested in leveraging ontological analysis and semantic technologies to improve cognitive transparency, social accountability, and participatory governance of artificial intelligence artifacts.