Formal Models of Legal Reasoning

We argue that legal argumentation, as the subject matter as well as a special subfield of Argumentation Studies (AS), has to be examined by making skilled use of the full panoply of tools such as argumentation and story schemes which are at the forefront of current work in AS. In reviewing the literature, we make explicit our own methodological choices (particularly regarding the place of normative deliberation in practical reasoning) and then illustrate the implications of such an approach through the (...) analysis of a case study in the English law of evidence. We argue that a clear distinction must be drawn between practical argumentation and stories. Because of the institutional separation between legal judgment and fact-finding in common-law jury trials, we argue for the combination of argument and story-based analysis. (shrink)

It’s widely accepted that normativity is not subject to truth values. The underlying reasoning is that truth values can only be predicated of descriptive statements; normative statements are prescriptive, not descriptive; thus truth value predicates cannot be assigned to normative statements. Hence, deonticity lacks logical semantics. This semantic monism has been challenged over the last decades from a series of perspectives that open the way for legal logics with imperative semantics. In the present paper I will go back to Kant (...) and review his understanding of practical judgments, presenting it as supported by a pluralistic semantics. From this perspective a norm of Law is a logical expression that includes as content a generic description of a possible behavior by a generality of juridical agents, and assigns to that content the assertion of its obligatory character, accompanied by a disincentive for non-compliance. From this perspective legal norms can be syntactically formalized and assigned appropriate semantic values in such terms that they can be incorporated into valid inferential schemes. The consequence is that we can put together legal logics that handle both the phenomenal and the deontic dimensions of legality. (shrink)

Langdellian “science” and its “formalism” ignore ways form permits and even creates freedom of choice. For example, as Wordsworth notes, though the weaver is restricted by what his form of loom can weave, the weaver may nonetheless choose what and how he weaves. Furthermore, the loom creates weaving possibilities that do not exist without it. Such freedom alongside form is often lost on lawyers, judges, and teachers trained primarily in Langdellian redacted appellate cases where “facts” and other framed matters often (...) wrongly appear as simply given. Similarly, in the context of their redacted appellate cases, many current students may only see constraint in IRAC (Issue-Rule-Application-Conclusion) and other thought forms rather than the fastidious freedoms such forms both provide and create. -/- Overlooking such freedoms is not only misleading in itself. It also misses the need to study how such freedoms are and should be exercised. When facts are simply presented as “given” and strategic and other choices go unrecorded and unnoticed in redacted appellate opinions, no thorough analysis of these overlooked subjects can occur. This is extremely troubling since such overlooked subjects are at the very heart of the lawyer’s craft. -/- Attempting to remedy such Langdellian shortcomings, this article explores, among other things, five basic levels of thought and the framing choices in such levels of thought: references, issues, rules, application of rules, and conclusions. Though often merely taken as “given” in redacted appellate opinions, a good grasp of reference assures that parties are in fact talking about the same matter or matters (the “reference”). It also increases the likelihood of ascertaining and properly framing all the relevant “facts” in a manner reasonably and ethically consistent with a client’s real interests. Similarly, focusing on flexibility of issue framing both brings necessary focus on what is important in the reference and, to the extent reasonable and ethical, again increases the likelihood of frames most consistent with a client’s real interests. A good grasp of applicable rules and how to frame and apply them on its face increases the likelihood of representing a client well. A good grasp of conclusions and how to frame and hedge them also does the same. -/- Grasping the multilevel complexities in play at these multiple levels pushes us beyond briefing redacted appellate cases to the much more difficult and stimulating work of exploring and teaching good legal thought at all its levels. Legal writing professors are pioneers in this regard and others in the academy can learn much from them. -/- Keywords: RIRAC, IRAC, CREAC, Reference, Issue, Analysis, Rule, Application, Conclusion, Frame, Framing, Metaphor, Concept, Category, Legal Thought, Legal Analysis, Rhetoric, Langdell, Wordsworth, Form, Formalism, Sonnet, Text. (shrink)

This paper challenges the Critical Legal Studies (CLS) claims of legal indeterminacy. It shall use a legal formalist logic and language as its main assertion, further maintaining that the CLS claims is only grounded in ambiguity and confusion. CLS is a legal theory that challenges and overturns accepted norms and standards in legal theory and practice. They maintained that law in the historical and contemporary society has an alleged impartiality, and it is used as a tool of privilege and power (...) – law is politics. Consequently, CLS maintained that these results to indeterminacy of law. Legal indeterminacy can be summed up as contrary to the common understanding that legal materials, statutes and case law, do not really answer legal disputes. Legal principles and doctrines, as CLS scholars claim, are said to be indeterminate, for it is riddle with gaps, conflicts, and anomalies that are widely present even in simple cases. Legal indeterminacy also rises because of the underlying political power – law is politics – that implicates law as merely a tool for oppression. This thesis shows that CLS assertions with legal indeterminacy is only grounded on ambiguity. On one hand, using the main concept of legal formalist logic and language grounded with sub-arguments: inherent generality of legal language, reasoned elaboration, and neutral principles, it refutes the CLS claims of legal indeterminacy. On the other, the paper maintains that their main reason of legal indeterminacy, ‘law is politics’, is merely a statement of fact that currently happens in society is sentimental and weak through counterexamples. (shrink)

Recent attempts to resolve the Paradox of the Gatecrasher rest on a now familiar distinction between individual and bare statistical evidence. This paper investigates two such approaches, the causal approach to individual evidence and a recently influential (and award-winning) modal account that explicates individual evidence in terms of Nozick's notion of sensitivity. This paper offers counterexamples to both approaches, explicates a problem concerning necessary truths for the sensitivity account, and argues that either view is implausibly committed to the impossibility of (...) no-fault wrongful convictions. The paper finally concludes that the distinction between individual and bare statistical evidence cannot be maintained in terms of causation or sensitivity. We have to look elsewhere for a solution of the Paradox of the Gatecrasher. (shrink)

Aunque el derecho probatorio y el derecho procesal se han dedicado desde siempre al estudio de los problemas relacionados con las pruebas y el establecimiento de los hechos en los procesos judiciales, el énfasis ha estado siempre en el aspecto formal, doctrinal y procedimental en detrimento de los fundamentos filosóficos y teóricos. Durante los últimos años ha habido un intento sostenido de explorar estos fundamentos combinando no sólo las herramientas tradicionales proporcionadas por la lógica, la gramática y la retórica, sino (...) también los avances hechos en ciencias como la estadística y la probabilidad, la medicina y la psicología forenses, la psicología de la percepción, la epistemología y la filosofía de la ciencia. El presente libro reúne las contribuciones de destacados juristas y filósofos latinoamericanos a esta nueva perspectiva interdisciplinaria, conocida como epistemología jurídica. El libro está dividido en tres grandes temas: la primera parte explora los problemas epistemológicos del conocimiento de los hechos en los procesos judiciales; la segunda se enfoca en el problema de los estándares de prueba; y la sección final discute el testimonio de los expertos. En su conjunto el libro ofrece un panorama tanto de los problemas centrales de la epistemología jurídica, como del estado del arte de la disciplina. (shrink)

En el presente artículo se examinan varias propuestas que abordan la argumentación como un ejercicio válido y necesario de control judicial; ello, a través del estudio de diversos elementos doctrinales, como lo son la representación democrática argumentativa, la interpretación previa y la debida justificación de las decisiones, así como la ponderación y la aplicación de los principios, entre otros. Al margen de lo anterior, nuestra intención no es otra sino la de presentar una descripción del estado del arte de dichas (...) cuestiones, el cual es presentado en un repaso detallado en varios planteamientos teóricos que, directa o indirectamente, evalúan el papel de la argumentación como eje del control judicial. (shrink)

Fifty years of effort in artificial intelligence (AI) and the formalization of legal reasoning have produced both successes and failures. Considerable success in organizing and displaying evidence and its interrelationships has been accompanied by failure to achieve the original ambition of AI as applied to law: fully automated legal decision-making. The obstacles to formalizing legal reasoning have proved to be the same ones that make the formalization of commonsense reasoning so difficult, and are most evident where legal reasoning has to (...) meld with the vast web of ordinary human knowledge of the world. Underlying many of the problems is the mismatch between the discreteness of symbol manipulation and the continuous nature of imprecise natural language, of degrees of similarity and analogy, and of probabilities. (shrink)

Presumption is a complex concept in law, affecting the dialogue setting. However, it is not clear how presumptions work in everyday argumentation, in which the concept of “plausible argumentation” seems to encompass all kinds of inferences. By analyzing the legal notion of presumption, it appears that this type of reasoning combines argument schemes with reasoning from ignorance. Presumptive reasoning can be considered a particular form of reasoning, which needs positive or negative evidence to carry a probative weight on the conclusion. (...) For this reason, presumptions shift the burden of providing evidence or explanations onto the interlocutor. The latter can provide new information or fail to do so: whereas in the first case the new information rebuts the presumption, in the second case, the absence of information that the interlocutor could reasonably provide strengthen the conclusion of the presumptive reasoning. In both cases the result of the presumption is to strengthen the conclusion of the reasoning from lack of evidence. As shown in the legal cases, the effect of presumption is to shift the burden of proof to the interlocutor; however, the shift a presumption effects is only the shift of the evidential burden, or the burden of completing the incomplete knowledge from which the conclusion was drawn. The burden of persuasion remains on the proponent of the presumption. On the contrary, reasoning from definition in law is a conclusive proof, and shifts to the other party the burden to prove the contrary. This crucial difference can be applied to everyday argumentation: natural arguments can be divided into dialectical and presumptive arguments, leading to conclusions materially different in strength. -/- . (shrink)

Concepts as reasonable doubt, cognitive biases and emotions are now a theoretical problem for the practice of law, and the law understood as legal argumentation. From a theoretical point of view, the screenplay written by Reginald Rose, Twelve Angry Men, is an outstanding example to analyze some of these concepts, and its influence on procedural stage. Cognitive biases and informal fallacies are theoretical challenge to legal argumentation.

Uses erotetic logic to model the courtroom objection "Improper Cross!". -/- Readers downloading the article should also please download the erratum et corrigendum, which is locally available.

This chapter briefly reviews the present state of judgment aggregation theory and tentatively suggests a future direction for that theory. In the review, we start by emphasizing the difference between the doctrinal paradox and the discursive dilemma, two idealized examples which classically serve to motivate the theory, and then proceed to reconstruct it as a brand of logical theory, unlike in some other interpretations, using a single impossibility theorem as a key to its technical development. In the prospective part, having (...) mentioned existing applications to social choice theory and computer science, which we do not discuss here, we consider a potential application to law and economics. This would be based on a deeper exploration of the doctrinal paradox and its relevance to the functioning of collegiate courts. On this topic, legal theorists have provided empirical observations and theoretical hints that judgment aggregation theorists would be in a position to clarify and further elaborate. As a general message, the chapter means to suggest that the future of judgment aggregation theory lies with its applications rather than its internal theoretical development. (shrink)

Note: The author holds the copyright, and there was no agreement, express or implied, not to use a facsimile PDF. -/- Using erotetic logic, the paper defines the "the whole truth" in a manner consistent with U.S. Supreme Court precedent. It cannot mean "the whole story," as witnesses in an adversary system are permitted /only/ to answer the questions put to them, nor are they permitted to speculate, add irrelevant material, etc. Nor can it mean not to add an admixture (...) of falsity, as that is already included in "nothing but the truth," and, strictly speaking, in "the truth," as any such as admixture renders the whole thing false (given bivalence is presupposed) by &-introduction. (shrink)