The author singles out various conceptions of rationality used in practical legal discourse: formal and substantive rationality, instrumental goal‐ and means‐rationality, communicative rationality. Practical rationality is expressed in decisions justified by epistemic and axiological premises according to the rules of justificatory reasoning. Five levels of analysis of this justification are identified. Rules, principles and evaluations are used as justifying arguments and their characteristics determine the dimensions of rationality of decision depending on the features of rules, various conceptions of principles, and (...) kinds of relativisation of evaluations. The dimensions of legal rationality depend mainly on three singled out conceptions of rationality, i.e., formal rationality dealing with the deep structure of justification, instrumentally oriented rationality as content of justifiability, and communicative rationality linked with the pragmatics of human interaction. Legitimacy, according to the presented analysis, appears as a subclass of external justification dealing with axiological premisses in terms of instrumental rationality and/or communicative rationality. (shrink)

Successful accounts of analogy in law have two burdens to discharge. First, they must reflect the fact that the conclusion of an argument by analogy is a normative claim about how to decide a certain case. Second, they must not fail to accord relevance to the fact that the source case was authoritatively decided in a certain way. We argue in the first half of this paper that the common view of the structure of analogical arguments in law cannot overcome (...) these hurdles. In the second half we develop an original account that aims to succeed where others failed. (shrink)

This paper deals with two issues in the field of reasoning by analogy in the law. The one issue is whether there exists such a thing as analogous rule application, or whether there is only the ‘normal’ application of a broadened rule. It is argued that if rules, as the entities made by a legislator, are distinguished from generalised solutions for cases, the idea of analogous application of rules makes sense. It is also shown how the so-called ‘reason-based model of (...) rule application’, in contrast to the traditional modus ponens or subsumption model, makes it easy to give a logical account of analogous rule application. The other issue is how to argue logically about whether two cases are sufficiently similar to adopt the outcome of the one case for the other case. Section 3 provides a general logical model to establish this. The model is based on the comparison of the reasons for and against a particular solution in the two cases. (shrink)

SummaryThis contribution offers an evaluation of e contrario reasoning in which the interpretation of a legal rule is based on the context of the law system (contextual e contrario reasoning). A model is presented which will show all the explicit and implicit elements of the argument at work and will also point out how these distinct parts are interrelated. By questioning the content and justificatory power of these elements, the weak spots in the argument can be laid bare. It will (...) be argued that e contrario reasoning inevitably requires a dubious argumentative step, which renders the argument intrinsically weak. The model is applied to a European lawsuit on French cheese. (shrink)

In this paper I investigate the similarities betweenthe dialectical procedure in the pragma-dialecticaltheory and dialectical procedures in AI and Law. I dothis by focusing on one specific type of reasoning inlaw: analogy argumentation. I will argue that analogyargumentation is not only a heuristic forfinding new premises, but also a part of thejustification of legal decisions. The relevantcriteria for the evaluation of analogy argumentationare not to be found at the logical level of inference,but at the procedural level of the discussion. I (...) willproceed as follows. I start with an outline ofPrakken's theory of argumentation frameworks andprocedural models. Then, I will discuss Peczenik'sanalysis of analogy argumentation and try to combineit with the descriptive-normative research ofMacCormick and Summers. Finally, I propose asystematization of the criteria for the evaluation ofanalogy argumentation within the framework of apragma-dialectical notion of an argumentation scheme. (shrink)

The presence of premises expressing comparison is a problem for the Aristotelian theory of the dialectical method, first because there is no general theory of comparison in the Organon and secondly because along with propositions on the opposition and inflexion of the terms, comparative statements seem to fall outside the explicit description which Aristotle gives of possible premises. The purpose of this paper is to offer a synthetic theory of comparisons according to Aristotle’s Topics , in an attempt both to (...) supply the aforementioned absence and to highlight the importance of the second problem. There are three main types of premises on the more, the less and the similar : some comparing the degree of possession of a predicate, others comparing the plausibility of a predication and finally, others expressing an analogy. Once expounded the very marked differences that occur between these three classes of propositions, the paper analyses the various kinds of argumentation based on comparative premises and offers a formalization of its logical laws. The complexity of this theory and the volume of topoi involved in the comparisons show the magnitude of a problem that has not been sufficiently studied. (shrink)

In this contribution two approaches of legal analogy-argumentation will be discussed: the traditional, monological approach and the dialogical approach. This contribution aims at answering the question in how far these approaches may serve as adequate instruments for rational reconstructions of this analogy-argumentation. We will also indicate along which lines the insights resulting from these approaches may be developed further in order to arrive at a more comprehensive and systematic method for a rational reconstruction of argumentation of this sort. We will (...) make use of the insights gained from the pragma-dialectical argumentation theory. (shrink)

This paper presents in outline Luigi Ferrajoli’s axiomatic and general theory of law, as developed in his lifelong work Principia Iuris . The first section focuses on the three main aspects of the theory: the methodological, the theoretical and the pragmatic, which respectively represent the theory’s syntax, semantics and its pragmatics. Ferrajoli identifies three deontic gaps of norms: firstly, the one between their validity and efficacy ; secondly, the one between their justice and validity ; and finally, and most importantly, (...) the one between validity and existence (i.e. normative force). The presence of such gaps is, according to Ferrajoli, the extraordinary innovation that entrenched constitutions have brought into modern legal systems, by establishing norms that are superior to statutes and case law. In this sense, all normative phenomena (except for the constitution itself) can be conceived both as norms and as facts. In the second section the role of juridical science is briefly discussed. (shrink)

In practical reasoning, reasonableness ‐ as opposed to rationality ‐ is an important concept. This paper explores the notion of reasonableness as applied exclusively to legal decisions. Conflicting values or legal requirements can make rationally deduced solutions unattainable, and may call for criteria of reasonableness, Conflicting values must be weighed, and weighed against each other, in search of a point of equilibrium between them. Legal cases are more or less difficult to solve, depending on the difficulty of finding a unique (...) optimal equilibrium. The relevance of factual and ideal consensus for the determination of a reasonable legal decision is underlined. Finally, a definition of “reasonable legal decision” is proposed. (shrink)

This essay discusses the developments and trends of research in legalargumentation of the last 25 years. The essay starts with a survey of thevarious approaches which can be distinguished: the logical approach, therhetorical approach, and the dialogical approach. Then it identifies varioustopics in the research, which constitute the various components of aresearch programme of legal argumentation: the philosophical component, thetheoretical component, the reconstruction component, the empiricalcomponent, and the practical component. It concludes with a discussion ofthe main trends in the research (...) of the last 25 years. (shrink)