Lon Fuller’s The Morality of Law (rev. ed. 1969) makes some engaging points about statutory interpretation. And, along the way, he develops an analogy I haven’t seen anywhere else in the statutory interpretation, comparing statutory interpretation to a surviving son’s effort to complete his deceased father’s unfinished invention. (In other words, he combines two of my favorite topics!)

After endorsing the Rule in Heydon’s Case (also called the Mischief Rule) as an interpretive framework, and offering a friendly amendment to it (p. 83 – “If any criticism can be made of this analysis, it is that it should have included a fifth point to be ‘discerned and considered,’ which might read somewhat as follows: ‘How would those who must guide themselves by its words reasonably understand the intent of the Act, for the law must not become a snare for those who cannot know the reasons of it as fully as do the Judges.’”), he offers this purposivist approach:

… An inventor of useful household devices dies leaving the pencil sketch of an invention on which he was working at the time of his death. On his deathbed he requests his son to continue work on the invention, though he dies without having had a chance to tell the son what purpose the invention was to serve or anything about his own plans for completing it. In carrying out his father’s wish the son’s first step would be to decide what the purpose of the projected invention was, what defect or insufficiency of existing devices it was intended to remedy. He would then try to grasp the underlying principle of the projected invention, the ‘true reason of the remedy’ in the language of Heydon’s Case. With these problems solved he would then proceed to work out what was essential to complete the design for the projected device.

Let us now ask of the son’s action questions of the sort commonly asked concerning the interpretation of statutes. Was the son faithful to his father’s intention? If we mean, ‘Did he carry out an intention the father had actually formed concerning the manner of completing the design?’ why, of course, the question is quite unanswerable for we do not know whether the father had any such intention, and if so, what it was. If we mean, ‘Did he remain within the framework set by the father, accepting the father’s conception of a need for the projected device and his father’s general approach to the problem of supplying that need?’ then the answer, on the facts supposed, is yes. If the son were able to call on his father’s spirit for help, the chances are that this help would take the form of collaborating with the son in the solution of a problem the father had left unsolved. So it is usually with difficult problems of interpretation. If the draftsman of a statute were called into direct consultation, he would normally have to proceed in the same manner as the judge by asking such questions as the following: Does this case fall within the mischief which the statute sought to remedy? Does it fall within the ‘true reason of the remedy’ appointed by the statute, that is, is the prescribed remedy apt for dealing with this particular manifestation of the general mischief at which the statute was aimed?

pp. 84-85. Note the invocation of collaborative partnership, rather than the (far more common) faithful agent approach (e.g., Judge Posner’s analogy to the Army captain who receives a truncated command by radio and must decide what to do).

Fuller also makes the following crucial point about the reciprocity between legislature and judiciary that undergirds a body of law worthy of the name:

With all its subtleties, the problem of interpretation occupies a sensitive, central position in the internal morality of the law. It reveals, as no other problem can, the cooperative nature of the task of maintaining legality. If the interpreting agent is to preserve a sense of useful mission, the legislature must not impose on him senseless tasks. If the legislative draftsman is to discharge his responsibilities he, in turn, must be able to anticipate rational and relatively stable modes of interpretation. This reciprocal dependence permeates in less immediately obvious ways the whole legal order. No single concentration of intelligence, insight, and good will, however strategically located, can insure the success of the enterprise of subjecting human conduct to the governance of rules.

p. 91

In this way, Fuller prefigures a point explored by Richard Pildes in his 1982 law student note in the Harvard Law Review, 95 Harv. L. Rev. 892 (1982). Pildes sought, in effect, to answer the question, what statutory interpretation approach by the judiciary legitimates the policy supremacy of the legislature? (The daring feature of Pildes’s project is, of course, the notion that legislative supremacy is as much in need of legitimation as is judicial interpretation of statutes.) It seems reasonably clear that Fuller would have answered something like, “Purposivism.” To which one can add: So much the better for purposivism. (See also Fuller at p. 106: “[L]aw is the enterprise of subjecting human conduct to the governance of rules. Unlike most modern theories of law, this view treats law as an activity and regards a legal system as the product of a sustained purposive effort.” ; and at p. 146: “A statute is obviously a purposive thing, serving some end or congeries of related ends.”)