The subject of this paper, Excuses, is one not to be treated, but only to be introduced, within such limits. It is, or might be, the name of a whole branch, even a ramiculated branch, of philosophy, or at least of one fashion of philosophy. I shall try, therefore, first to state what the subject is, why it is worth studying, and how it may be studied, all this at a regrettably lofty level: and then I shall illustrate, in more (...) congenial but desultory detail, some of the methods to be used, together with their limitations, and some of the unexpected results to be expected and lessons to be learned. Much, of course, of the amusement, and of the instruction, comes in drawing the coverts of the microglot, in hounding down the minutiae, and to this I can do no more here than incite you. But I owe it to the subject to say, that it has long afforded me what philosophy is so often thought, and made, barren of -- the fun of discovery, the pleasures of co-operation, and the satisfaction of reaching agreement. (shrink)

In this paper we describe an approach to practical reasoning, reasoning about what it is best for a particular agent to do in a given situation, based on presumptive justifications of action through the instantiation of an argument scheme, which is then subject to examination through a series of critical questions. We identify three particular aspects of practical reasoning which distinguish it from theoretical reasoning. We next provide an argument scheme and an associated set of critical questions which is able (...) to capture these features. In order that both the argument scheme and the critical questions can be given precise interpretations we use the semantic structure of an Action-Based Alternating Transition System as the basis for their definition. We then work through a detailed example to show how this approach to practical reasoning can be applied to a problem solving situation, and briefly describe some other previous applications of the general approach. In a second example we relate our account to the social laws paradigm for co-ordinating multi-agent systems. The contribution of the paper is to provide firm foundations for an approach to practical reasoning based on presumptive argument in terms of a well-known model for representing the effects of actions of a group of agents. (shrink)

Robots are now associated with various aspects of our lives. These sophisticated machines have been increasingly used in different manufacturing industries and services sectors for decades. During this time, they have been a factor in causing significant harm to humans, prompting questions of liability. Industrial robots are presently regarded as products for liability purposes. In contrast, some commentators have proposed that robots be granted legal personality, with an overarching aim of exonerating the respective creators and users of these artefacts from (...) liability. This article is concerned mainly with industrial robots that exercise some degree of self-control as programmed, though the creation of fully autonomous robots is still a long way off. The proponents of the robot’s personality compare these machines generally with corporations, and sporadically with, inter alia, animals, and idols, in substantiating their arguments. This article discusses the attributes of legal personhood and the justifications for the separate personality of corporations and idols. It then demonstrates the reasons for refusal of an animal’s personality. It concludes that robots are ineligible to be persons, based on the requirements of personhood. (shrink)

In this paper we consider persuasion in the context of practical reasoning, and discuss the problems associated with construing reasoning about actions in a manner similar to reasoning about beliefs. We propose a perspective on practical reasoning as presumptive justification of a course of action, along with critical questions of this justification, building on the account of Walton. From this perspective, we articulate an interaction protocol, which we call PARMA, for dialogues over proposed actions based on this theory. We outline (...) an axiomatic semantics for the PARMA Protocol, and discuss two implementations which use this protocol to mediate a discussion between humans. We then show how our proposal can be made computational within the framework of agents based on the Belief-Desire-Intention model, and illustrate this proposal with an example debate within a multi agent system. (shrink)

Autonomous vehicles are one of the most spectacular recent developments of Artificial Intelligence. Among the problems that still need to be solved before they can fully autonomously participate in traffic is the one of making their behaviour conform to the traffic laws. This paper discusses this problem by way of a case study of Dutch traffic law. First it is discussed to what extent Dutch traffic law exhibits features that are traditionally said to pose challenges for AI & Law models, (...) such as exceptions, rule conflicts, open texture and vagueness, rule change, and the need for commonsense knowledge. Then three approaches to the design of law-conforming AV are evaluated in light of the challenges posed by Dutch traffic law, which includes an assessment of the usefulness of AI & Law models of nonmonotonic reasoning, argumentation and case-based reasoning. (shrink)

There is an increasing need for norms to be embedded in technology as the widespread deployment of applications such as autonomous driving, warfare and big data analysis for crime fighting and counter-terrorism becomes ever closer. Current approaches to norms in multi-agent systems tend either to simply make prohibited actions unavailable, or to provide a set of rules which the agent is obliged to follow, either as part of its design or to avoid sanctions and punishments. In this paper we argue (...) for the position that agents should be equipped with the ability to reason about a system’s norms, by reasoning about the social and moral values that norms are designed to serve; that is, perform the sort of moral reasoning we expect of humans. In particular we highlight the need for such reasoning when circumstances are such that the rules should arguably be broken, so that the reasoning can guide agents in deciding whether to comply with the norms and, if violation is desirable, how best to violate them. One approach to enabling this is to make use of an argumentation scheme based on values and designed for practical reasoning: arguments for and against actions are generated using this scheme and agents choose between actions based on their preferences over these values. Moral reasoning then requires that agents have an acceptable set of values and an acceptable ordering on their values. We first discuss how this approach can be used to think about and justify norms in general, and then discuss how this reasoning can be used to think about when norms should be violated, and the form this violation should take. We illustrate how value based reasoning can be used to decide when and how to violate a norm using a road traffic example. We also briefly consider what makes an ordering on values acceptable, and how such an ordering might be determined. (shrink)

In this paper 1 1 This is a version of a paper originally presented at ArgMAS 2014. we address some limitations with proposals concerning an argumentation scheme for practical reasoning grounded on action-based alternating transition systems augmented with values. In particular, we extend the machinery to enable the proper representation of, and ability to reason with, goals. This allows the more satisfactory representation of certain critical questions, and the means to explicitly record differences between agents as to what will count (...) as the fulfillment of goals and the promotion of values. It also allows us to express desires in terms of values, and to make plain the relation between a change in circumstances and the promotion and demotion of values. Three detailed examples are used to illustrate the additional kinds of problem the extensions allow us to consider. (shrink)

Norms provide a valuable mechanism for establishing coherent cooperative behaviour in decentralised systems in which there is no central authority. One of the most influential formulations of norm emergence was proposed by Axelrod :1095–1111, 1986). This paper provides an empirical analysis of aspects of Axelrod’s approach, by exploring some of the key assumptions made in previous evaluations of the model. We explore the dynamics of norm emergence and the occurrence of norm collapse when applying the model over extended durations. It (...) is this phenomenon of norm collapse that can motivate the emergence of a central authority to enforce laws and so preserve the norms, rather than relying on individuals to punish defection. Our findings identify characteristics that significantly influence norm establishment using Axelrod’s formulation, but are likely to be of importance for norm establishment more generally. Moreover, Axelrod’s model suffers from significant limitations in assuming that private strategies of individuals are available to others, and that agents are omniscient in being aware of all norm violations and punishments. Because this is an unreasonable expectation, the approach does not lend itself to modelling real-world systems such as online networks or electronic markets. In response, the paper proposes alternatives to Axelrod’s model, by replacing the evolutionary approach, enabling agents to learn, and by restricting the metapunishment of agents to cases where the original defection is observed, in order to be able to apply the model to real-world domains. This work can also help explain the formation of a “social contract” to legitimate enforcement by a central authority. (shrink)

The design and analysis of norms is a somewhat neglected topic in AI and Law, but this is not so in other areas of Computer Science. In recent years powerful techniques to model and analyse norms have been developed in the Multi-Agent Systems community, driven both by the practical need to regulate electronic institutions and open agent systems, and by a theoretical interest in mechanism design and normative systems. Agent based techniques often rely heavily on enforcing norms using the software (...) to prevent violation, but I will also discuss the use of sanctions and rewards, and the conditions under which compliance by autonomous agents (including humans) can be expected or encouraged without sanctions or rewards. In the course of the paper a suggested framework for the exploration of these issues is developed. (shrink)

The paper discusses the potential value of a deontic approach to database specification. More specifically, some different types of integrity constraints are considered and a distinction is drawn between necessary (hard) and deontic (soft) constraints.Databases are compared with other normative systems. A deontic logic for database specification is proposed and the problems of how to react to, and of how to correct, or repair, a situation which arises through norm violation are discussed in the context of this logic. The limitations (...) of the proposed logic and possible modifications and extensions of it are analysed. (shrink)

In ethics, ‘probabilism’ refers to a position defended by a number of Catholic theologians, mainly in the sixteenth and seventeenth centuries. They held that, when one is uncertain which of a range of actions is the right one to perform, it is permissible to perform any which has a good chance of being the right one—even if there is another which has a better chance. This paper considers the value of this position from the viewpoint of modern ethical philosophy. The (...) unusual nature of probabilism as a theory focusing upon permissibility, rather than right-making properties, is explored and related to some modern attempts to set out ‘satisficing’ and ‘hybrid’ ethical theories. Such theories try to distinguish between what is best and what is permissible, and probabilism can be understood as an alternative way of supplementing a theory of right-making properties by adding to it a theory of permissibility. But a more radical version is also possible, where one abandons any attempt to identify right actions or right-making properties, and instead considers permissibility alone. Accordingly, a ‘multi-account theory’ of permissibility is proposed and defended as a model of how many people actually make moral decisions. (shrink)