"In the tripartite structure of the U.S. federal government, it is the job of courts to say what the law is, as Chief Justice John Marshall announced in 1803. When courts render decisions on the meaning of statutes, the prevailing view is that a judge’s task is not to make the law, but rather to interpret the law made by Congress. The two main theories of statutory interpretation— purposivism and textualism—disagree about how judges can best adhere to this ideal of legislative supremacy. The problem is especially acute in instances where it is unlikely that Congress anticipated and legislated for the specific circumstances being disputed before the court. While purposivists argue that courts should prioritize interpretations that advance the statute’s purpose, textualists maintain that a judge’s focus should be confined primarily to the statute’s text.
Regardless of their interpretive theory, judges use many of the same tools to gather evidence of
statutory meaning. First, judges often begin by looking to the ordinary meaning of the statutory
text. Second, courts interpret specific provisions by looking to the broader statutory context.
Third, judges may turn to the canons of construction, which are presumptions about how courts
ordinarily read statutes. Fourth, courts may look to the legislative history of a provision. Finally, a
judge might consider how a statute has been—or will be—implemented. Although both
purposivists and textualists may use any of these tools, a judge’s theory of statutory interpretation
may influence the order in which these tools are applied and how much weight is given to each