A Logic for Reasoning about Group Norms

We present a number of modal logics to reason about group norms. As a preliminary step, we discuss the ontological status of the group to which the norms are applied, by adapting the classification made by Christian List of collective attitudes into aggregated, common, and corporate attitudes. Accordingly, we shall introduce modality to capture aggregated, common, and corporate group norms. We investigate then the principles for reasoning about those types of modalities. Finally, we discuss the relationship between group norms and types of collective responsibility

Towards a Logic of Epistemic Theory of Measurement

We propose a logic to reason about data collected by a num- ber of measurement systems. The semantic of this logic is grounded on the epistemic theory of measurement that gives a central role to measure- ment devices and calibration. In this perspective, the lack of evidences (in the available data) for the truth or falsehood of a proposition requires the introduction of a third truth-value (the undetermined). Moreover, the data collected by a given source are here represented by means of a possible world, which provide a contextual view on the objects in the domain. We approach (possibly) conflicting data coming from different sources in a social choice theoretic fashion: we investigate viable opera- tors to aggregate data and we represent them in our logic by means of suitable (minimal) modal operators

Aggregazione di giudizi

L’aggregazione di opinioni individuali per formare una decisione collettiva è l’oggetto di studio di Judgment Aggregation, una disciplina che coinvolge logica, economia, filosofia politica ed informatica. Il problema della presa di decisione collettiva a partire da posizioni individuali è comune nella vita di tutti i giorni e, sebbene la procedura da seguire sembri evidente, i risultati possono nascondere paradossi sorprendenti. La formalizzazione del problema dell’aggregazione di giudizi individuali ha permesso di portare un buon numero di risposte, di evidenziare legami con la teoria della scelta sociale e l’aggregazione di credenze, e di aprire la strada a nuove ricerche che permettono di applicare buona parte dei risultati ad altri paradigmi della decisione collettiva. Obiettivo di questo lavoro è di introdurre il problema dell’aggregazione di giudizi, motivare l’interesse per tali questioni, presentando i risultati principali ottenuti e indicando alcune delle piste di ricerca attuali.The aggregation of individual opinions to form a collective decision is the object of study of Judgment Aggregation, a discipline involving logic, economics, political philosophy and computer science. The problem of collective decision-making from individual positions arises in everyday life and, although the procedure to follow seems evident, the results can hide surprising paradoxes. The formalization of the problem of the aggregation of individual judgements has made it possible to bring a good number of answers, to highlight links with social choice theory and the aggregation of beliefs, and to pave the way to new research that allows to apply most of the results to other paradigms of collective decision-making. The aim of this work is to introduce the problem of judgement aggregation, to motivate interest in such issues, presenting the main results obtained so far and highlighting some of the current research tracks