ARTICLE CONTENTS INTRODUCTION I. THE LINGUISTIC INDETERMINACY THEORY OF PATENT LAW A. Background on Patents B. The Problem of Claim Meaning II. THE INTERPRETATION-CONSTRUCTION DISTINCTION A. A Simple Example B. Interpretation 1. What Is Interpretation? 2. The Problem of Apparent Ambiguity 3. The Problem of Unfamiliar Language C. Construction 1. What Is Construction? 2. Choosing a Second-Order Theory of Construction 3. Filling Gaps and Drawing Lines on Vagueness D. Payoffs III. APPLYING THE INTERPRETATION-CONSTRUCTION DISTINCTION TO PATENT LAW A. An Initial Outline 1. Interpreting the Linguistic Meaning of Claims 2. Constructing the Legal Effect of Claims B. An Illustration: Phillips v. AWH Corp. 1. Interpretation 2. Construction C. Prior Articulations of the Interpretation-Construction Distinction in Patent Law IV. WHY DISPUTES ARE OVER CONSTRUCTION A. The Conventional Framing: Dictionary Versus Specification as Guides to Linguistic Meaning B. The Real Dispute: Linguistic Meaning Versus the "Tree" Invention 1. Doctrine Treats the Patentee's Invention as Equivalent to the Linguistic Meaning of Claim Text 2. The Patentee's Invention Is Not the Linguistic Meaning of Claim Text 3. Examples of Conflation C. The Consequences of Conflation 1. The Incorrect Diagnosis of Linguistic Indeterminacy 2. Obscuring Judicial Policy-Making 3. Conflating Linguistic Context with Policy Context 4. The Demise of the Construction-to-Save-Validity Doctrine D. Disputes over Gap-Filling Construction 1. The Problem of Vagueness 2. The Problem of Deliberate Ambiguity 3. The Problem of Irreducible Ambiguity V. WHY DISPUTES ARE NOT ABOUT LINGUISTIC MEANING A. Our Existing Interpretative Tools Are Adequate B. Reversal Rates Do Not Prove Linguistic Ambiguity C. Theories of Linguistic Ambiguity Are Not Plausible 1. The Scientific Jargon Theory 2. The Evolving Language Theory 3. The Radical Indeterminacy Theory VI. IMPLICATIONS A. Linguistic Tools and Claim Interpretation B. Policy Arguments and Claim Construction C. The Resolution of Vagueness D. The Role of Institutional Allocation CONCLUSION INTRODUCTION
The uncertainty over how courts will apply patent claims in adjudicating infringement is a real and very substantial problem in patent law today. A large literature addresses this problem. (1) The common premise of this literature is that the uncertainty arises because claim language is itself uncertain, (2) and the proposals for reform accordingly focus on linguistic solutions. (3) For example, judges and scholars debate whether the best source of linguistic meaning is dictionary definitions, (4) or the context provided by the whole patent document, (5) or testimony from expert witnesses. (6) A closely related debate is institutional: whether appellate judges, trial judges, or juries are best equipped to implement a particular linguistic solution and discern linguistic meaning. (7) At the pessimistic extreme, Dan Burk and Mark Lemley argue that claim language is so innately indeterminate that it should be abolished altogether. (8) Although the proposed solutions vary widely, there is wide agreement that the source of the difficulty is that claim language is vague or ambiguous. (9) We will call this the "linguistic indeterminacy thesis."
This Article challenges the widely shared premise. The uncertainty in how courts will apply claims does not characteristically arise because of uncertainty regarding linguistic meaning. There may be some occasional cases in which linguistic ambiguity (where language has more than one sense) produces underdeterminacy of legal outcomes, and more cases in which vagueness (where language has borderline cases) causes uncertainty; but we argue that uncertainty in claim application most typically arises because judges have core policy disagreements about the underlying goals of claim construction. In order to explicate and distinguish between these different sources of uncertainty, we will draw upon what has been called the "interpretation-construction distinction" in recent constitutional theory. (10)
Stated simply, modern constitutional theory draws a distinction between determining the linguistic meaning of a text ("interpretation"), and giving legal effect to that text ("construction"). (11) To take an example, there is some uncertainty in constitutional law about the contours of the state action doctrine as applied to the First Amendment. (12) But the source of this uncertainty is not linguistic indeterminacy, and the answer to the doctrinal problem cannot be found in better evidence about linguistic practices in the late eighteenth century. The linguistic meaning of the First Amendment's state action requirement--that "Congress" is bound--is clear. The cause of the uncertainty is not that people do not know what "Congress" means as a matter of semantics, but that strictly limiting the First Amendment to congressional action--and allowing other government actors to establish religions and censor speech--would result in outcomes that seem unwise or unjust. Courts react to this problem by engaging in constitutional construction: the courts craft constitutional doctrine with a broader scope of application for the First Amendment. Uncertainty about this doctrine results when judges disagree on how much broader the scope should be in light of the underlying reasons of policy and principle. This normative dispute over legal effect is very different from a dispute about the semantic meaning of the word "Congress."
The interpretation-construction distinction does not tell us how to resolve these disputes over legal effect. Rather, the payoff of drawing the distinction is antecedent: it tells us which issues are problems of linguistic meaning, and which issues are problems of legal effect. This is important because the two types of problems call for different solutions. More and better linguistic information (such as more accurate definitions or data about usage) can solve problems of linguistic uncertainty and hence result in more accurate interpretations. Linguistics cannot resolve policy debates and thus cannot resolve issues of construction. The limits of linguistics are especially apparent when the linguistic meaning of a claim underdetermines the claim's legal effect. We shall call the space where linguistic information underdetermines legal effect the "construction zone."
The confusion between interpretation and construction--and the use of the wrong tools because of a misdiagnosis of the problem--is endemic in patent law. As mentioned above, the premise of the literature has been that the problems of claim construction stem from linguistic uncertainty. The same is true of the case law. The leading modern case on analyzing patent claims (we will use "analysis" to denote an activity that encompasses both interpretation and construction) is Phillips v. AWH Corp., (13) which deals with whether a patent claim to "steel baffles" covered non-bullet-deflecting steel baffles. Reflecting the consensus that the problem with claims is their linguistic indeterminacy, the opinion features an extended discussion of the role of dictionaries and other sources in determining linguistic meaning. (14) But this was a fool's errand. Nobody in Phillips--none of the litigants, and none of the judges in the majority or the two dissents-disputed the linguistic meaning of "steel baffle" or that this linguistic meaning covered a non-bullet-deflecting baffle. (15) The dispute in Phillips was over the wisdom of giving legal effect to this linguistic meaning, because the patentee's stated purpose for the invention was a bullet-resistant reinforced wall, while the accused product did not deflect bullets. (16) Giving legal effect to the semantic meaning would thus arguably extend the monopoly scope of the patent to something that the patentee had not really invented. What Phillips really represents is a conflict about the underlying goal of claim construction: is it to give effect to the linguistic meaning of text, or is it to tailor patent scope to the real invention? As we will explain, these two goals are fundamentally different, and the inquiry becomes incoherent--and uncertain--when judges oscillate between them.
In this Article, we are not taking a position on the question whether allowing patentees a broader monopoly than what they had invented or foreseen is good patent policy; that is a question for another day. Our point is that the interpretation-construction distinction provides a conceptual tool that allows scholars, lawyers, and judges to identify this policy disagreement as the true cause of disputes. Because most disputes over claim "meaning" are actually normative disputes over policy issues, a solution to the claim construction debate cannot be found in better linguistic sources. Efforts at reform should focus instead on resolving the policy disagreement among judges.
Here is a road map. Part I provides background on patent claims and describes the conventional debate about problems in claim analysis, which attributes uncertainty to textual defects. Part II then begins by laying out a general theory for analyzing legal texts, in particular distinguishing between the interpretation of linguistic meaning and the construction of legal effect. We then lay out the kinds of problems that are generally addressed through interpretation, and the kinds of problems that generally fall under the rubric of construction. We will also distinguish between two kinds of construction. At a high level, courts engage in construction by determining whether to follow the linguistic meaning of text or to follow something else in making their decisions. At a lower level, ira court chooses to follow the linguistic meaning of text, it must decide how to fill in the gaps when the linguistic meaning does not fully answer a legal dispute (i.e., the dispute falls within the construction zone). As we will explain, both types of...