Argumentation Schemes for Statutory Interpretation: A Logical Analysis

This paper shows how defeasible argumentation schemes can be used to represent the logical structure of the arguments used in statutory interpretation. In particular we shall address the eleven kinds of argument identified MacCormick and Summers [6] and the thirteen kinds of argument by Tarello [11]. We show that interpretative argumentation has a distinctive structure where the claim that a legal text ought or may be interpreted in a certain way can be supported or attacked by arguments, whose conflicts may have to be assessed according to further arguments. 1. Background: Arguments in Interpretation This paper aims at developing a fresh formal analysis of interpretive arguments, i.e., arguments meant to support a particular interpretation of a statutory test, and to justify its choice over competing interpretations. Our theoretical framework is based on three different dimensions: legal theories on interpretive arguments, argumentation theories for analysing such arguments, and argumentation logics for formalising them. In this section we will briefly present the legal doctrinal backgrounds for our formal analysis: MacCormick and Summers’s [6] analysis of interpretive arguments, Tarello’s [11] classification of interpretation canons, and Alexy and Dreier’s [1] analysis of criteria for solving interpretive conflicts. Generally speaking, the so-called interpretation canons — i.e., the different rules to be applied to interpreting statutes — that are employed in legal systems can be viewed as patterns for constructing arguments aimed at justifying certain interpretations, while attacking other interpretations. 1.1. The Proposal of MacCormick and Summers MacCormick and Summers [6, 464-5], summarising the outcomes of a vast study on statutory interpretation, involving scholars from many different legal systems, distinguish eleven types of arguments: 1. Arguments from ordinary meaning express the principle that if a statutory provision can be interpreted according to the meaning a native speaker of a given language would ascribe to it, it should be interpreted in this way, unless there is a reason for a different interpretation. 2. Arguments from technical meaning express the principle that if a statutory provision concerns a special activity that has a technical language, it ought to be interpreted in the appropriate technical sense, as opposed to its ordinary meaning. 3. Arguments from contextual harmonization express the principle that if the statutory provision belongs to a larger scheme in a statute or set of statutes, it should be interpreted in light of the whole statute it is part of, or in light of other statutes it is related to. 4. Arguments from precedent express the principle that if a statutory provision has a previous judicial interpretation, it should be interpreted in conformity with it. Where there is a hierarchy of courts, this principle needs to be applied in such a way to imply that the lower court must conform to the judgment of higher one. 5. Arguments from analogy express the principle that if a statutory provision is similar to provisions of other statutes, then it should be interpreted to preserve the similarity of meaning, even if this requires a departure from ordinary meaning. 6. Arguments from a legal concept express the principle that if the general legal concept has been previously recognized and doctrinally elaborated in law, it should be interpreted in such a way as to maintain a consistent use of the concept through the system as a whole. 7. Arguments from general principles express the principle that whenever general principles, including principles of law, are applicable to the statutory provision, one should favour the interpretation of that is most in conformity with these general legal principles. 8. Arguments from history express the principle that if the statute has come to be interpreted over a period of time in accord with the historically evolved understanding of a particular point, its application to a case should be interpreted in line with this historically evolved understanding. 9. Arguments from purpose express the principle that if a purpose can be ascribed to a statutory provision, or even to the whole statute, the provision should be interpreted as applied to a particular case in a way compatible with this purpose. 10. Arguments from substantive reasons express the principle that if there is some goal that can be considered to be fundamentally important to the legal order, and if the goal can be promoted by one rather than another interpretation of the statutory provision, then the provision should be interpreted in accord with the goal. 11. Arguments from intention express the principle that if a legislative intention concerning a statutory provision can be identified, the provision should be interpreted in line with that intention. 1.2. The Proposal of Tarello Some years before the comparative inquiry of MacCormick and Summers, a list of interpretive arguments was developed by Tarello [11, Ch. 8]. While being based mainly on the Italian tradition, this categorisation has had a broad influence also outside Italy, being adopted in particular by Perelman [9, 55-9]: 1. Arguments a contrario exclude interpretations according to which a legal statement explicitly saying “if A then B” is given the meaning “if A or C then B”, where C is any proposition not entailed by A. 2. Arguments a simili ad simile (or analogical) support interpretations according to which, a term in a legal statetment is extended to include entities that are not literally included in its scope, but present a relevant similarity with the entities literally included. 3. Arguments a fortiori support interpretations of a legal statement according to which a term in the statement, which apparently denotes a single class of subjects or acts, is extended to other subjects or acts, since these additional subjects or acts deserve to a larger extent the normative qualification linked to that term. 4. Arguments from completeness of the legal regulation exclude interpretations that create legal gaps. 5. Arguments from the coherence of the legal regulation exclude interpretations of different legal statements that make them conflicting. 6. Psychological arguments support interpretations driven by the actual intent of the authors of legal text (for instance, on the basis of the travaux préparatories). 7. Historical arguments support interpretations giving a legal statement the same meaning that was traditionally attributed to other statements governing the same matter. 8. Apagogical arguments exclude the interpretation of a normative statement that generates an absurdity. 9. Teleological arguments support the interpretation of a legal statement by attributing to it a rational purpose which is identified from the goals or interests that the law is supposed to promote; 10. Parsimony arguments exclude interpretations that are redundant under the assumption that the legislator does not make useless normative statements. 11. Authoritative arguments support interpretations already given by any authoritative judicial or doctrinal subject. 12. Naturalistic arguments support interpretations aligning a legal statement to human nature or the nature of the matter regulated by that statement. 13. Arguments from equity support (exclude) (un)fair or (un)just interpretations. 14. Arguments from general principles support (exclude) interpretations that are suggested by (incompatible with) general principles of the legal system. Tarello’s list complements MacCormick and Summers’ list, since the latter focuses on the kinds of input on which the interpretive argument is based (ordinary language, technical language, statutory context, precedent, etc.) while the first focuses on the reasoning steps by which the interpretive argument is constituted. 1.3. Priorities and Conflicts between Interpretive Arguments Interpretive argument can be in conflict one against another, leading to opposite conclusions. In fact, as MacCormick [5] observes, “there may be arguments of many types available, and each is capable of generating an interpretation of a given text at variance with that generated by some other possible argument”. To address such conflicts, we need to assume or argue that one of the conflicting arguments is stronger than its competitors. Some legal traditions provide indeed general criteria for addressing conflicts of arguments on the basis of their priorities. For instance, Alexy and Dreier [1, 95ff.] indicate various criteria according to which conflicts between interpretive arguments are adjudicated in German law: 1. In criminal law, arguments based on the wording of the text to be applied have strong priority. 2. In criminal law arguments based on ordinary meaning take priority over arguments which refer to technical terminology. 3. A strong priority for the wording obtains where the state wishes to interfere with individual rights of freedom. 4. A strong priority for the wording obtains for prescriptions on time limits. 5. A weak priority for arguments based on wording obtains in general. 6. Genetic arguments, based on the intention of the historical legislator, prevail over argument not based on authority (i.e., argument not based on the historical legislator’s intention, on precedent, or on dogmatic consensus), though not over linguistic arguments. 7. Rightness reasons based on the constitution or on superior sources have precedence over those who are not so grounded. 8. The idea that a scrutiny is required when limitations to individual liberties are at issue has led some to the idea, refused by others, that substantive arguments based on individual rights prevail over arguments based on collective goals. 1.4. A General Structure for Interpretive Arguments By analysing the different interpretive canons we can may identify a shared structure including the following elements: an expression E (word, phrase, sentence, etc.)