In this presentation, advances in modeling the mental dynamics of norms will be presented. In particular, the process from norm-adoption, possibly yielding new normative goals, to different forms of norm compliance will be focused upon, including norm internalization, which is at study in social-behavioral sciences and moral philosophy since long. Of late, the debate was revamped within the rationality approach pointing to the role of norm internalization as a less costly and more re- liable enforcement system than social control. So far, poor attention was paid to the mental underpinnings of internalization. In this presentation, a rich cognitive model of different types, degrees and factors of internalization is shown. The initial implementation of this model on EMIL-A, a normative agent architecture developed and applied to the.

The starting point of the following remarks is that a fundamental aspect of judicial decisions (mainly in trial courts but often also in appellate courts) is the judgment about the facts in issue. In a sense, actually, judicial decisions derive from a sort of combination of legal and factual judgments. Lawyers - and logicians - usually deal with the legal dimension of these decisions and analyze the features and the structure of legal arguments and of legal justifications of a decision. However, the factual dimension of such decisions is no less important since -as it is commonly said- no decision is just if it is based upon the wrong facts.

To decide which norms can be removed from a system, we need to know when a norm is redundant. After shifting the focus of attention in deontic logic from detachment of obligations and permissions to deontic redundancy, I discuss in this paper five benchmark examples of deontic redundancy in reasoning about permissions, intermediate concepts and constitutive norms, deontic dilemmas, temporal deontic reasoning and contrary-to-duty reasoning. Then I discuss those benchmark examples in four formal approaches to deontic reasoning: traditional model logic, dynamic approaches, violation oriented or diagnostic systems, and imperativist or norm based approaches.

We propose a normal modal deontic logic based on a dyadic operator, similar in structure to the temporal “until”. By bringing significant expressiveness to the logic, it allows both the definition of a monadic desirability operator similar to the SDL obligation, and the expression of the relative level of desirability of target formulae. The interpretation of this logic on a linear structure of worlds ordered by desirability makes its semantics more intuitive and concrete than the SDL deontic accessibility relation. We also show that the core modality of the logic permits to represent the Chisholm and Forrester paradoxes of deontic logic in a more precise way, which does not lead to inconsistencies.

This paper looks at deontic logic as resulting from both a betterness ordering on states (i.e., a `deontic preference') and a priority ordering on properties (i.e., a `law' explicitly representing a standard of behavior). The correspondence between these two orderings offers a rich perspective from which to look at deontic scenarios and puzzles, and in particular at contrary-to-duties. The framework naturally lends itself to describing dynamics involving both orderings, thereby providing a new analysis of norm change as `betterness change'.

RoCTL* was proposed to model and specify the robustness of reactive systems. RoCTL* extended CTL* with the addition of Obligatory and Robustly operators, which quantify over failure-free paths and paths with one more failure respectively. This paper gives an axiomatisation for all the operators of RoCTL* with the exception of the Until operator; this fragment is able to express similar contrary-to-duty obligations to the full RoCTL* logic. We call this formal system NORA, and give a completeness proof. We also consider the fragments of the language containing only path quantifiers (but where variables are dependent on histories). We examine semantic properties and potential axiomatisations for these fragments.

The aim of this paper is to strengthen the point made by Horty about the relationship between reason holism and moral particularism. In the literature prima facie obligations have been considered as the only source of reason holism. I strengthen Horty's point in two ways. First, I show that contrary-to-duties provide another independent support for reason holism. Next I outline a formal theory that is able to capture these two sources of holism. While in simple settings the proposed account coincides with Horty's one, this is not true in more complicated or "realistic” settings in which more than two norms collide. My chosen formalism is so-called input/output logic.

We show that a recently developed theory of positive permission based on the notion of derogation is hampered by a triviality result that indicates a problem with the underlying full-meet contraction operation. We suggest a solution that presupposes a particular normal form for codes of norms, adapted from the theory of relevance through propositional letter sharing. We then establish a correspondence between contractions on sets of norms in input/output logic (derogations), and AGM-style contractions on sets of formulae, and use it as a bridge to migrate results on propositional relevance from the latter to the former idiom. Changing the concept accordingly we show that positive permission now incorporates a relevance requirement that wards off triviality.

In earlier works, we used Defeasible Logic to argue that techniques from belief and base revision encounter a number of difficulties in modelling legal dynamics. In particular, we showed that these techniques are not suitable when legal changes are retroactive. This suggested to adopt a different logical model able to express two main timelines, one internal to a given temporal version of the legal system, and another relative to how the legal system evolves over time. In this paper, we adjust our view and show that, under some restrictions, ideas from base revision, if applied to Defeasible Logic or to similar rule-based systems, can indeed capture some significant aspects of annulments, abrogations, and derogations.

The aim of the present paper is to provide a metalogical systematisation in the area of deontic action logic based on Boolean algebra. Differences among the systems in question lie in two aspects: the level of closedness of a deontic action logic and the possibility of performing no action at all. It is also shown that the existing definitions of obligation in those systems are not acceptable due to their unintuitive interpretation or paradoxical consequences. As a solution we propose an axiomatic characterisation of obligation with an adequate class of models.

In this paper, we present an adaptive logic for deontic conflicts, called P2.1r , that is based on Goble's logic SDLaPe - a bimodal extension of Goble's logic P that invalidates aggregation for all prima facie obligations. The logic P2.1r has several advantages with respect to SDLaPe. For consistent sets of obligations it yields the same results as Standard Deontic Logic and for inconsistent sets of obligations, it validates aggregation “as much as possible”. It thus leads to a richer consequence set than SDLaPe. The logic P2.1r avoids Goble's criticisms against other non-adjunctive systems of deontic logic. Moreover, it can handle all the `toy examples' from the literature as well as more complex ones.

This paper examines the deontic logic of the Talmud. We shall find, by looking at examples, that at first approximation we need deontic logic with several connectives: O_T A (Talmudic obligation); F_T A (Talmudic prohibition); F_D A (Standard deontic prohibition); O_D A (Standard deontic obligation). In classical logic one would have expected that deontic obligation O_D is definable by O_D A = F_D ¬A and that O_T and F_T are connected by O_T A = F_T ¬A. This is not the case in the Talmud for the T (Talmudic) operators, though it does hold for the D operators. We must change our underlying logic. We have to regard {O_T,F_T} and {O_D,F_D} as two sets of operators , where O_T and F_T are independent of one another and where we have some connections between the two sets. We shall list the types of obligation patterns appearing in the Talmud and compare Talmudic Logic with modern deontic logic.

This paper introduces Exclusion Logic - a simple modal logic without negation or disjunction. We show that this logic has an efficient decision procedure. We describe how Exclusion Logic can be used as a deontic logic. We compare this deontic logic with Standard Deontic Logic and with more syntactically restricted logics.

Privacy policies are often defined in terms of permitted messages. Instead, in this paper we derive dynamically the permitted messages from static privacy policies defined in terms of permitted and obligatory knowledge. With this new approach, we do not have to specify the permissions and prohibitions of all message combinations explicitly. To specify and reason about such privacy policies, we extend a multi-modal logic introduced by Cuppens and Demolombe with update operators modeling the dynamics of both knowledge and privacy policies. We show also how to determine the obligatory messages, how to express epistemic norms, and how to check whether a situation is compliant with respect to a privacy policy.We axiomatize and prove the decidability of our logic.

Compliance is often achieved `by design' through a coherent system of controls consisting of information systems and procedures . This system-based control requires a new approach to auditing in which companies must demonstrate to the regulator that they are `in control'. They must determine the relevance of a regulation for their business, justify which set of control measures they have taken to comply with it, and demonstrate that the control measures are operationally effective. In this paper we show how value-based argumentation theory can be applied to the compliance domain. Corporate values motivate the selection of control measures (actions) which aim to fulfill control objectives, i.e. adopted norms (goals). In particular, we show how to formalize the dialogue in which companies justify their compliance decisions to regulators using value-based argumentation. The approach is illustrated by a case study of the safety and security measures adopted in the context of EU customs regulation.

We provide a logical analysis of private international law, the body of law establishing when courts of a country should decide a case (jurisdiction) and what legal system they should apply to this purpose (choice of law). A formal model of the resulting interaction among multiple legal systems is proposed based on modular argumentation. It is argued that this model may be useful for understanding this rather esoteric, but increasingly important, domain of the law. Moreover, it might be useful for modelling the way in which interactions between heterogeneous agents, belonging to different and differently regulated virtual societies, can be governed without recourse to a central regulatory agency.

In 1926, Ernst Mally proposed the first system of deontic logic. His system turned out to be unacceptable. How can it be repaired? We discuss several proposals to reformulate it in terms of strict implication, relevant implication and strict relevant implication.

The paper presents a logical framework for the integration of interactions between institutional agents, human agents and software agents. It is shown, through a case study, that the relationships between actions performed by these three kinds of agents are defined in terms of the Searle's ”counts as” concept and their justifications are based on the roles hold by human agents or by a causal relationships between human agent actions and software agent actions. The logical framework concentrates on the concepts of counts as, causality and role.

Sometimes it is impossible to attribute responsibility to individuals when something goes wrong, or right, especially when many different agents are involved. Moral norms may dictate that certain events are not to happen, but responsibility can only be attributed to an agent if this agent was able to do the right thing, she knew what she ought to do, and she did not accidentally fail in completing her task. The fact that we cannot attribute responsibility for certain unfortunate events due to the absence of these conditions is called the problem of many hands. This contribution presents a logical analysis of the problem of many hands in the framework of XSTIT with intentions, as developed by Jan Broersen. The problem of many hands is analysed in terms of an inference from the existence of a norm and the fact that all agents are acting responsibly to the conclusion that the norm is obeyed. To make that inference valid, additional assumptions are necessary, to ensure that the fairness conditions are met. As the formal analysis shows, tasks can be distributed so as to minimize the gap in this inference, but it cannot be completely bridged: at some point we have to acknowledge that moral responsibility falls short of guaranteeing moral norm fulfilment.

The aim of this work is to propose a model-theoretic semantics and a complete logic for the dynamics of commitments. In the first part of the article, a formalization of the concept of social commitment in STIT logic is presented. STIT is one of the most prominent formal accounts of agency. It is the logic of constructions of the form "agent i sees to it that φ”. In the second part, the article presents an extension of STIT logic by dynamic operators which enable to describe two basic operations on commitment: commitment creation and commitment cancelation. The logic is used to develop an axiomatic and semantic analysis of commitment change in multi-agent systems.

The purpose of this contribution is to set up a language to evaluate the results of concerted action among interdependent agents against predetermined properties that we can recognise as desirable from a deontic point of view. Unlike the standard view of logics to reason about coalitionally rational action, the capacity of a set of agents to take a rational decision will be restricted to what we will call agreements, that can be seen as solution concepts to a dependence structure present in a certain game. The language will identify in concise terms those agreements that act accordingly or disaccordingly with the desirable properties arbitrarily set up in the beginning, and will reveal, by logical reasoning, a variety of structural properties of this type of collective action.