|General Rules of Interpretation|
|General Theories of Interpretation|
Statutory interpretation is the process by which courts interpret and apply legislation. Some amount of interpretation is always necessary when a case involves a statute. Sometimes the words of a statute have a plain and straightforward meaning. But in many cases, there is some ambiguity or vagueness in the words of the statute that must be resolved by the judge. To find the meanings of statutes, judges use various tools and methods of statutory interpretation, including traditional canons of statutory interpretation, legislative history, and purpose. In common law jurisdictions, the judiciary may apply rules of statutory interpretation to legislation enacted by the legislature or to delegated legislation such as administrative agency regulations.
General principles 
The judiciary interprets how legislation should apply in a particular case as no legislation unambiguously and specifically addresses all matters. Legislation may contain uncertainties for a variety of reasons:
- Words are imperfect symbols to communicate intent. They are ambiguous and change in meaning over time.
- Unforeseen situations are inevitable, and new technologies and cultures make application of existing laws difficult.
- Uncertainties may be added to the statute in the course of enactment, such as the need for compromise or catering to special interest groups.
Therefore, the court must try to determine how a statute should be enforced. This requires statutory construction. It is a tenet of statutory construction that the legislature is supreme (assuming constitutionality) when creating law and that the court is merely an interpreter of the law. Nevertheless in practice, by performing the construction the court can make sweeping changes in the operation of the law.
Conflicts between sources of law 
Where legislation and case law are in conflict, there is a presumption that legislation takes precedence insofar as there is any inconsistency. In the United Kingdom this principle is known as Parliamentary Sovereignty. In Australia and in the United States, the courts have consistently stated that the text of the statute is used first, and it is read as it is written, using the ordinary meaning of the words of the statute.
- U.S. Supreme Court: "[I]n interpreting a statute a court should always turn to one cardinal canon before all others. . . .[C]ourts must presume that a legislature says in a statute what it means and means in a statute what it says there." Connecticut Nat'l Bank v. Germain, 112 S. Ct. 1146, 1149 (1992). Indeed, "when the words of a statute are unambiguous, then, this first canon is also the last: 'judicial inquiry is complete.'" 503 U.S. 249, 254.
- Supreme Court of Virginia: "Every part of an act is presumed to be of some effect and is not to be treated as meaningless unless absolutely necessary." Raven Coal Corp. v. Absher, 153 Va. 332, 335, 149 S.E. 541, 542 (1929).
- Supreme Court of Alaska: "In assessing statutory language, unless words have acquired a peculiar meaning, by virtue of statutory definition or judicial construction, they are to be construed in accordance with their common usage." Muller v. BP Exploration (Alaska) Inc., 923 P.2d 783, 787-88 (Alaska 1996);
- Arkansas Supreme Court: "When reviewing issues of statutory interpretation, we keep in mind that the first rule in considering the meaning and effect of a statute is to construe it just as it reads, giving the words their ordinary and usually accepted meaning in common language. When the language of a statute is plain and unambiguous, there is no need to resort to rules of statutory construction. A statute is ambiguous only where it is open to two or more constructions, or where it is of such obscure or doubtful meaning that reasonable minds might disagree or be uncertain as to its meaning. When a statute is clear, however, it is given its plain meaning, and this court will not search for legislative intent; rather, that intent must be gathered from the plain meaning of the language used. This court is very hesitant to interpret a legislative act in a manner contrary to its express language, unless it is clear that a drafting error or omission has circumvented legislative intent." Farrell v. Farrell, 365 Ark. 465, 231 S.W.3d 619. (2006)
- Supreme Court of New Mexico: "The principal command of statutory construction is that the court should determine and effectuate the intent of the legislature using the plain language of the statute as the primary indicator of legislative intent." State v. Ogden, 118 N.M. 234, 242, 880 P.2d 845, 853 (1994) “The words of a statute . . . should be given their ordinary meaning, absent clear and express legislative intention to the contrary,” as long as the ordinary meaning does “not render the statute’s application absurd, unreasonable, or unjust.” State v. Rowell, 121 N.M. 111, 114, 908 P.2d 1379, 1382 (1995) When the meaning of a statute is unclear or ambiguous, we have recognized that it is “the high duty and responsibility of the judicial branch of government to facilitate and promote the legislature’s accomplishment of its purpose.” State ex rel. Helman v. Gallegos, 117 N.M. 346, 353, 871 P.2d 1352, 1359 (1994). - New Mexico v. Juan, 2010-NMSC-041, August 9, 2010
- U.S. Court of Appeals for the Second Circuit: "As in all statutory construction cases, we begin with the language of the statute. The first step is to determine whether the language at issue has a plain and unambiguous meaning with regard to the particular dispute in the case." Barnhart v. Sigmon Coal Co., 534 U.S. 438, 450 (2002) "[U]nless otherwise defined, statutory words will be interpreted as taking their ordinary, contemporary, common meaning." United States v. Piervinanzi, 23 F.3d 670, 677 (2d Cir. 1994).
Federal jurisdictions may presume that either federal or local government authority prevails in the absence of a defined rule. In Canada, there are areas of law where provincial governments and the federal government have concurrent jurisdiction. In these cases the federal law is held to be paramount. However, in areas where the Canadian constitution is silent, the federal government does not necessarily have superior jurisdiction. Rather, an area of law that is not expressly mentioned in Canada's Constitution will have to be interpreted to fall under either the federal residual jurisdiction found in the preamble of s. 91 -- known as the Peace, Order and Good Government clause -- or the provinces residual jurisdiction of "Property and Civil Rights" under s. 92(13) of the 1867 Constitution Act. This contrasts with other federal jurisdictions, notably the United States and Australia, where it is presumed that if legislation is not enacted pursuant to a specific provision of the federal Constitution, the states will have authority over the relevant matter in their respective jurisdictions.
Internal and external consistency 
It is presumed that a statute will be interpreted so as to be internally consistent. A particular section of the statute shall not be divorced from the rest of the act. The ejusdem generis (or eiusdem generis, Latin for "of the same kind") rule applies to resolve the problem of giving meaning to groups of words where one of the words is ambiguous or inherently unclear. The rule results that where "general words follow enumerations of particular classes or persons or things, the general words shall be construed as applicable only to persons or things of the same general nature or kind as those enumerated." 49 F. Supp. 846, 859. Thus, in a statute forbidding the concealment on one's person of "pistols, revolvers, derringers, or other dangerous weapons," the term "dangerous weapons" may be construed to comprehend only dangerous weapons of the kind enumerated, i.e., firearms, or perhaps more narrowly still, handguns. A hypothetical court may have to determine whether a sword, a Japanese throwing star, or a Taser fit into the "other" category of the statute. Here, the term "other dangerous weapons" must be given a meaning of the "same kind" as the word of established meaning.
A statute shall not be interpreted so as to be inconsistent with other statutes. Where there is an inconsistency, the judiciary will attempt to provide a harmonious interpretation.
Statements of the legislature 
Legislative bodies themselves may try to influence or assist the courts in interpreting their laws by placing into the legislation itself statements to that effect. These provisions have many different names, but are typically noted as:
- Declarations, sometimes suffixed with of Policy or of Intent; or
- Sense of Congress, or of either house in multi-chamber bodies.
Also known as canons of construction, canons give common sense guidance to courts in interpreting the meaning of statutes. Most canons emerge from the common law process through the choices of judges. Proponents of the use of canons argue that the canons constrain judges and limit the ability of the courts to legislate from the bench. Critics argue that a judge always has a choice between competing canons that lead to different results, so judicial discretion is only hidden through the use of canons, not reduced.
Textual canons are rules of thumb for understanding the words of the text. Some of the canons are still known by their traditional Latin names.
- Plain meaning
- When writing statutes, the legislature intends to use ordinary English words in their ordinary senses. The United States Supreme Court discussed the plain meaning rule in Caminetti v. United States, 242 U.S. 470 (1917), reasoning "[i]t is elementary that the meaning of a statute must, in the first instance, be sought in the language in which the act is framed, and if that is plain... the sole function of the courts is to enforce it according to its terms." And if a statute's language is plain and clear, the Court further warned that "the duty of interpretation does not arise, and the rules which are to aid doubtful meanings need no discussion."
- Ejusdem generis ("of the same kinds, class, or nature")
- When a list of two or more specific descriptors is followed by more general descriptors, the otherwise wide meaning of the general descriptors must be restricted to the same class, if any, of the specific words that precede them. For example, where "cars, motor bikes, motor powered vehicles" are mentioned, the word "vehicles" would be interpreted in a limited sense (therefore vehicles cannot be interpreted as including airplanes).
- Expressio unius est exclusio alterius ("the express mention of one thing excludes all others")
- Items not on the list are impliedly assumed not to be covered by the statute or a contract term. However, sometimes a list in a statute is illustrative, not exclusionary. This is usually indicated by a word such as "includes" or "such as."
- In pari materia ("upon the same matter or subject")
- When a statute is ambiguous, its meaning may be determined in light of other statutes on the same subject matter.
- Noscitur a sociis ("a word is known by the company it keeps")
- When a word is ambiguous, its meaning may be determined by reference to the rest of the statute.
- Reddendo singula singulis ("refers only to the last")
- When a list of words has a modifying phrase at the end, the phrase refers only to the last, e.g., firemen, policemen, and doctors in a hospital.
- Generalia specialibus non derogant ("the general does not detract from the specific")
- Described in The Vera Cruz (1884) 10 App. Cas. 59 as: "Now if anything be certain it is this, that where there are general words in a later Act capable of reasonable and sensible application without extending them to subjects specially dealt with by earlier legislation, you are not to hold that earlier legislation indirectly repealed, altered, or derogated from merely by force of such general words, without any evidence of a particular intention to do so." This means that if a later law and an earlier law are potentially—but not necessarily—in conflict, courts will adopt the reading that does not result in an implied repeal of the earlier statute. Lawmaking bodies usually need to be explicit if they intend to repeal an earlier law.
Substantive canons instruct the court to favor interpretations that promote certain values or policy results.
- "Charming Betsy" Canon
- National statute must be construed so as not to conflict with international law. See Murray v. The Charming Betsy, 6 U.S. (2 Cranch) 64 (1804): "It has also been observed that an act of Congress ought never to be construed to violate the law of nations if any other possible construction remains..."
- Interpretation in Light of Fundamental Values
- Statute does not violate fundamental societal values. See, for example, Holy Trinity Church v. United States, 143 U.S. 457 (1892).
- Rule of Lenity
- In construing an ambiguous criminal statute, the court should resolve the ambiguity in favor of the defendant. See McNally v. United States, 483 U.S. 350 (1987); See, e.g., Muscarello v. U.S., 524 U.S. 125 (1998) (declining to apply the rule of lenity); Evans v. U.S., 504 U.S. 255 (1992) (Thomas, J., dissenting); Scarborough v. U.S., 431 U.S. 563 (1977) (Stewart, J., dissenting); See United States v. Santos (2008).
- Avoidance of abrogation of state sovereignty
- See Gregory v. Ashcroft, 501 U.S. 452 (1991); see also Gonzales v. Oregon, 546 U.S. 243 (2006); see also Nevada Dept. of Human Resources v. Hibbs, 538 U.S. 721 (2003)
- "Indian" Canon
- National statute must be construed in favor of Native Americans. See Chickasaw Nation v. United States, 534 U.S. 84 (2001): "statutes are to be construed liberally in favor of Indians with ambiguous provisions interpreted to their benefit." This canon can be likened to the doctrine of contra proferentem in contract law.
Deference canons instruct the court to defer to the interpretation of another institution, such as an administrative agency or Congress. These canons reflect an understanding that the judiciary is not the only branch of government entrusted with constitutional responsibility.
- Deference to Administrative Interpretations (US Chevron deference)
- If a statute administered by an agency is ambiguous with respect to the specific issue, the courts will defer to the agency's reasonable interpretation of the statute. This rule of deference was formulated by the United States Supreme Court in Chevron v. Natural Resources Defense Council, 467 U.S. 837 (1984).
- Avoidance Canon (Canon of Constitutional Avoidance)
- If a statute is susceptible to more than one reasonable construction, courts should choose an interpretation that avoids raising constitutional problems. In the US, this canon has grown stronger in recent history. The traditional avoidance canon required the court to choose a different interpretation only when one interpretation was actually unconstitutional. The modern avoidance canon tells the court to choose a different interpretation when another interpretation merely raises constitutional doubts.
- Clear statement rule
- When a statute may be interpreted to abridge long-held rights of individuals or states, or make a large policy change, courts will not interpret the statute to make the change unless the legislature clearly stated it. This rule is based on the assumption that the legislature would not make major changes in a vague or unclear way, and to ensure that voters are able to hold the appropriate legislators responsible for the modification.
- Leges posteriores priores contrarias abrogant (Subsequent laws repeal those before enacted to the contrary, aka "Last in Time")
- When two statutes conflict, the one enacted last prevails.
Critics of the use of canons argue that canons impute some sort of "omniscience" to the legislature, suggesting that it is aware of the canons when constructing the laws. In addition, it is argued that the canons give a credence to judges who want to construct the law a certain way, imparting a false sense of justification to their otherwise arbitrary process. In a classic article, Karl Llewellyn argued that every canon had a "counter-canon" that would lead to the opposite interpretation of the statute.
However, it could be argued that the fundamental nature of language is to blame for the problem of "for every canon, a counter." Interpreting whether a statute applies to a given set of facts often boils down to analyzing whether a single word or short phrase covers some element of the factual situation before the judge. The expansiveness of language necessarily means that there will often be good (or equally unconvincing) arguments for two competing interpretations. A judge is then forced to resort to documentation of legislative intent, which may also be unhelpful, and then finally to his or her own judgment of what outcome is ultimately fair and logical under the totality of the circumstances. Canons of statutory construction give judges the ability to decide questions of statutory interpretation that necessarily rely on an element of judicial discretion.
European perception 
Following the German scholar Friedrich Carl von Savigny (1779-1861) the four main interpretation methods are:
- Grammatical interpretation: using the literal meaning of the statutory text ("grammatical" is actually the wrong word, but it is commonly used for this type of interpretation).
- Historical interpretation: using the legislative history, to reveal the intent of the legislator.
- Systematic interpretation: considering the context of provisions, if only by acknowledging in which chapter a provision is listed.
- Teleological interpretation: then the purpose of the law is considered.
It is controversial whether certain interpretation methods must be preferred. Germans prefer a "grammatical" (literal) interpretation, because the statutory text has a democratic legitimation, and "sensible" interpretations are risky, in particular in view of German history. "Sensible" means different things to different people. The modern common law perception that courts actually make law is very different. All of the above methods may seem reasonable:
- It may be considered undemocratic to ignore the literal text, because only that text was passed through democratic processes. Indeed, there may be no single legislative "intent" other than the literal text that was enacted by the legislature, because different legislators may have different views about the meaning of an enacted statute. It may also be considered unfair to depart from the literal text because a citizen reading the literal text may not have fair notice that a court would depart from its literal meaning, nor fair notice as to what meaning the court would adopt. It may also be unwise to depart from the literal text if judges are generally less likely than legislatures to enact wise policies.
- But it may also seem unfair to ignore the intent of the legislators, or the system of the statutes. So for instance in Dutch law, NO general priority sequence for the above methods is recognized.
It should be noted that the freedom of interpretation largely varies by area of law. Criminal law and tax law must be interpreted very strictly, and never to the disadvantage of citizens, but liability law sometimes is even interpreted contra legem, because here (usually) both parties are citizens.
Over time, various methods of statutory construction have fallen in and out of favor. Some of the better known rules of construction methods are:
See also 
- Interpretation Act
- Judicial activism
- Judicial interpretation
- Legal interpretation in South Africa
- Statutory term analysis
- Rule of law
- Pepper v. Hart  AC 573
- Norman J. Singer, Sutherland Statutory Construction, 6th Edition, Vol. 1A, §20.12 (West Group 2000)
- American Jurisprudence 2d, Vol. 73, "Statutes" (West Group 2001)
- Garner, Bryan A.. Ed. In Chief. (1999). Black’s Law Dictionary (7th ed.). St. Paul, MN: West Publishing. p. 602.
- Einer Elhauge. Statutory Default Rules: How to Interpret Unclear Legislation. Harvard University Press (2008), p. 237–39. ISBN 978-0-674-02460-1.
- "United States v. Jin Fuey Moy", 241 U.S. 394, 401 (1916).
- Einer Elhauge. Statutory Default Rules: How to Interpret Unclear Legislation. Harvard University Press (2008), p. 148. ISBN 978-0-674-02460-1.
- Green v. Bock Laundry Machine Co., 490 U.S. 504 (1989).
- Karl N. Llewellyn, Remarks on the Theory of Appellate Decision and the Rules of Canons About How Statutes are to be Construed, 3 Vand. L. Rev. 395 (1950) repubished with permission in 5 Green Bag 297 (2002).
Further reading 
- CRS Report for Congress: "Statutory interpretation: General Principles and Recent Trends" (public domain - can be copied into article with citations)
- The multi-volume Sutherland Statutory Construction is the authoritative text on the rules of statutory construction.
- Karl Llewellyn, Remarks on the Theory of Appellate Decisions and the Rules or Canons About How Statutes Are to Be Construed 3 Vand. L. Rev. 395 (1950).
- United States of America v. William C. Scrimgeour 636 F.2d 1019 (5th Cir. 1981) discusses most aspects of statutory construction.
- Brudney & Ditslear, Canons of Construction and the Elusive Quest for Neutral Reasoning
- Sinclair, Michael, "Llewellyn's Dueling Canons, One to Seven: A Critique". New York Law School Law Review, Vol. 51, Fall 2006.
- Jon May, "Statutory Construction: Not For The Timid", The Champion Magazine (NACDL), January/February 2006.
- Corrigan & Thomas, “Dice Loading” Rules Of Statutory Interpretation, 59 NYU Annual Survey Of American Law 231, 238 (2003).
- The Rules of Statutory Construction (Virginia)
- Statutory Interpretation, by Ruth Sullivan, 1997. Canadian examples and explanations.
- Menahem Pasternak, Christophe Rico, Tax Interpretation, Planning, and Avoidance: Some Linguistic Analysis, 23 Akron Tax Journal, 33 (2008) (http://www.uakron.edu/law/lawreview/taxjournal/atj23/docs/Pasternak08.pdf).