Introduction to legal reasoning[*]

This is a book about legal reasoning. But it is not a book about a lot of the reasoning that lawyers, judges, and ordinary citizens engage in when they deal with legal matters. Some laws - for instance, the tax codes - require people to do mathematical calculations.

What we mean here by legal reasoning is the reasoning required to determine what the law is rather than the reasoning required to apply it. And applying the law requires not only types of reasoning that are not our topic but also requires, if one is in court, reasoning about what the evidence shows and also reasoning applying such legal doctrines as res judicata and collateral estoppel to determine whether the legal issue for which the evidence is adduced has already been conclusively decided.

Determining what the law is, although it is not all the reasoning required when we engage with the law - as the examples above illus­trate - is nonetheless a topic worth a book-length treatment. That is because every aspect of it is controversial. In our treatment of it we will present and argue for our views about the controverted matters. At the same time, however, we will present opposing views and what we think are the best arguments put forward for those views. Legal reasoning - reasoning required to determine what the law is - has been surrounded by an air of mystery, at least since Sir Edward Coke described the common law as ‘an Artificial perfection of reason' (Coke 1639). Legal decision-making is frequently described as a ‘craft', one that involves special forms of reasoning accessible only to those with legal training and experience (Kronman 1995; Fried 1981; see also Leiter 1996).

Our view is that the reasoning used to determine the law is just ordi­nary reasoning - moral, empirical, and deductive.

Here is how we proceed. Part I describes the circumstances that give rise to law and sets out our understanding of the most important prob­lems of jurisprudence. This is important as background for our analy­sis of legal reasoning.

Part II takes up the methodology of interpreting canonical legal texts - a vast array that includes constitutions, statutes, administrative rules and orders, and judicially crafted rules, as well as the legally authori­tative texts constitutive of private ordering (contracts, wills, trusts, deeds, leases, and so on). Our basic position is that interpretation, properly so-called, consists in recovering the meaning intended by the texts' authors. In defending that position, we explore its many compet­itors, such as textualism, dynamic interpretation, and the employment of highest-level purposes or concepts. In addition, we examine the interpreter's predicament when there is no authors' intended meaning, or when that intended meaning is absurd or perverse. Finally, we ask whether interpreting a constitution is fundamentally different from interpreting other canonical legal texts.

Part III addresses legal reasoning in the application and development of common law. We have several aims in this part of the book. We hope to clarify the reasoning methods judges use, to demonstrate that a variety of other supposed methods of legal decision-making are illusory, and to explain the different roles judges occupy within the legal system, as adjudicators and as lawmakers.

We also look at the techniques lawgivers use to guide decision-making by actors and adjudicators. They may establish determinate rules that require only interpretation in context. Alternatively, they may employ legal ‘standards' that delineate a zone of decision-making and define certain broad objectives that guide decision-making by future reasoners.

In sum, we find no ground for the claim that judges and others acting under law employ special methods of reasoning different from the methods employed by all reasoners in all contexts that call for decision-making. This holds true with respect both to the interpreta­tion of legal texts and to common law adjudication.