Law And Logic

The study presented in this book was entered upon by me from a legal point of view. 'Legal logic' has been known for a long time, concerning itself with the methodology of legal and in particular judicial reasoning. In modern days, however, this 'legal logic' is sometimes also connected with modern formal logic, as it has been developed in the works of G. Boole, A. de Morgan, G. Frege, C.S. Peirce, E. Schroder, G. Peano, A.N. Whitehead, B. Russell and others. For me this gave rise to the as yet not very specific question about the meaning of modern symbolic logic for law. Already in an early stage it appeared that, although traditional legal logic and modern symbolic logic both concern logic, this may not create the misapprehension that a similar matter is at issue. Both concern themselves (among other things) with reasonings and reasoning. Traditional legal logic is, however, as it was said by the German legal theoretician K. Engisch: "a material logic that wants us to reflect on what we have to do if we -within the limits of actual possibility- wish to reach true, or at least correct judgements" (Engisch, 1964, p.5). Modern symbolic logic on the other hand is not concerned with the truth or correctness of the result of an argument, but with its validity, i.e. the question when or under which conditions the truth (correctness) of the conclusion is guaranteed by the truth (correctness) of the premisses.

This book tackles the basics of legal reasoning in twelve chapters, including the principles of classic logic, deductive and inductive reasoning, application of the Socratic method to legal reasoning, and formal and material fallacies.

Have you ever read a legal opinion and come across an odd term like the fallacy of denying the antecedent, the fallacy of the undistributed middle, or the fallacy of the illicit process and wondered how you missed that in law school? You’re not alone: every day, lawyers make arguments that fatally trespass the rules of formal logic—without realizing it—because traditional legal education often overlooks imparting the practical wisdom of ancient philosophy as it teaches students how to “think like a lawyer.” In his book, The Force of Logic: Using Formal Logic as a Tool in the Craft of Legal Argument, lawyer and law professor Stephen M. Rice guides you to develop your powers of legal reasoning in a new way, through effective tips and tactics that will forever change the way you argue your cases. Rice contends that formal logic provides tools that help lawyers distinguish good arguments from bad ones and, moreover, that they are simple to learn and use. When you know how to recognize logical fallacies, you will not only strengthen your own arguments, but you will also be able to punch holes in your opponent’s—and that can make the difference between winning and losing. In this book, Rice builds on the theoretical foundation of formal logic by demonstrating logical fallacies through the use of anecdotes, examples, graphical illustrations, and exercises for you to try that are derived from common case documents. It is a hands-on primer that presents a practical approach for understanding and mastering the place of formal logic in the art of legal reasoning. Whether you are a lawyer, a judge, a scholar, or a student, The Force of Logic will inspire you to love legal argument, and appreciate its beauty and complexity in a brand new way.

The present study which I have subtitled A Study in Law and Logic was prompted by the question of whether an investigation into law and legal systems could lead to the discovery of unrevealed fundamental patterns common to all such systems. This question was further stimulated by two interrelated problems. Firstly, could an inquiry be rooted in specifically legal matters, as distinct from the more usual writings on deontic logic? Secondly, could such inquiry yield a theory which would nevertheless embrace a strict and simple logical structure, permitting substantive conclusions in legal matters to be deduced from simple rules governing some basic concepts? Before the development of deontic logic, W. N. Hohfeld devoted his efforts to this question at the beginning of this century. However, with this exception, few jurists have studied the interrelation between law and logic projected in this way. Nevertheless, two great names are to be found, Gottfried Wilhelm Leibniz and Jeremy Bentham-both philo sophers with legal as weIl as logical training. Bentham's investigations of logical patterns in law have only recently attracted attention; and as for Leibniz, his achievements are still almost totally unexplored (his most important writings on law and logic have not even been translated from Latin). My initial interest in the question was evoked by Professor Stig Kanger. Although primarily a logician and philosopher, Stig Kanger has been interested also in the fundamentals of legal theory.

Provides an essential introduction to classical logic.

Studies in Legal Logic is a collection of nine interrelated papers about the logic, epistemology and ontology of law. All of the papers were written after the publication of the author’s Reasoning with Rules and supplement the issues addressed therein. Some of the papers are new; others have been revised substantially after the publication of their original versions. The emphasis is on analysis, not on logical technicalities. Studies in Legal Logic contains chapters about the nature of norms, the role of coherence in the law, the nature of defeasibility, the role of dialectics in law and artificial intelligence, the statics and dynamics of the law, and the consistency of rules. Moreover, it contains a new, simplified and yet more powerful version of Reason-based Logic and extensive examples of how it can be used for the analysis of legal reasoning. The examples deal with legal theory construction, case-based reasoning, and judicial proof.

This book presents the current state of the art regarding the application of logical tools to the problems of theory and practice of lawmaking. It shows how contemporary logic may be useful in the analysis of legislation, legislative drafting and legal reasoning concerning different contexts of law making. Elaborations of the process of law making have variously emphasised its political, social or economic aspects. Yet despite strong interest in logical analyses of law, questions remains about the role of logical tools in law making. This volume attempts to bridge that gap, or at least to narrow it, drawing together some important research problems—and some possible solutions—as seen through the work of leading contemporary academics. The volume encompasses 20 chapters written by authors from 16 countries and it presents diversified views on the understanding of logic (from strict mathematical approaches to the informal, argumentative ones) and differentiated choices concerning the aspects of law making taken into account. The book presents a broad set of perspectives, insights and results into the emerging field of research devoted to the logical analysis of the area of creation of law. How does logic inform lawmaking? Are legal systems consistent and complete? How can legal rules be represented by means of formal calculi and visualization techniques? Does the structure of statutes or of legal systems resemble the structure of deductive systems? What are the logical relations between the basic concepts of jurisprudence that constitute the system of law? How are theories of legal interpretation relevant to the process of legislation? How might the statutory text be analysed by means of contemporary computer programs? These and other questions, ranging from the theoretical to the immediately practical, are addressed in this definitive collection.