12 September 2009

Classification and its Continents

Reading a concise note from the Max Planck Institut für Wissenschaftsgeschichte on 'Patent Classification and Scientific Taxonomies: Law as a Space of History of Science?', Hanoch Dagan's 2006 paper 'Legal Realism and the Taxonomy of Private Law' and Emily Sherwin's 'Legal Taxonomy' in 15 Legal Theory (2009) 25-54, the latter a variant on her 2006 paper. HLA Hart can wait till tomorrow.

The Max Planck note concerns the International Patent Classification (IPC), created by the international Strasbourg Agreement of 1971 and administered by WIPO. The Classification
represents a hierarchically structured legal taxonomy in which technological and biological objects are classified into sections, classes, subclasses and groups. Although its primary activity is one of ordering scientific and technological objects, the patent classificatory scheme is mainly understood as a legal exercise.
The note comments that
the IPC is engaged in a certain mode of (re-)production of scientific objects as legal properties (as inventions), as well as constituting relations between these different properties by placing them into a hierarchical order of past inventions. In a way, the IPC can be understood as a mapping exercise, which creates novel (the question is: legal, scientific, or both?) relations between objects on the basis of a legal perception of scientific "nature". In other words, the IPC represents an unofficial site of scientific classification; however, it is one which is put to nonimmediate, nonscientific use.

The third interesting aspect about the IPC conjoins the preceding observations. IPC’s practice of cutting and intermediating between what is taken to be a novel (inventive) scientific object and objects already known to society as belonging to the legal category of "prior art" – in other words, the accumulated body of scientific knowledge generally known – exerts peculiar ontological effects. On the one hand, the IPC could be understood as a metaphor for the reality of different kinds of scientific objects. On the other hand, the metaphor could also be taken as a means: as ways by which a nonnegligible kind of scientific history and reality are generated.
Civilisation and its discontents, nu, as we stack concepts and creatures in a hierarchy of boxes.

Sherwin's article derives from
the ambition to taxonomize law and the different methods a legal taxonomer might employ. Three possibilities emerge.

The first is a formal taxonomy that classifies legal materials according to rules of order and clarity. Formal taxonomy is primarily conventional and has no normative implications for judicial decision-making.

The second possibility is a function-based taxonomy that classifies laws according to their social functions. Function-based taxonomy can influence legal decision-making indirectly, as a gatekeeping mechanism, but it does not provide decisional standards for courts. Its objective is to assist in analysis and criticism of law by providing an overview of the body of legal doctrine.

The third possibility is a reason-based taxonomy that classifies legal rules and decisions according to the moral principles or "legal principles" thought to justify them. Reason-based taxonomy of this type offers courts a set of high-level decisional rules drawn from legal data. Its objective is to guide courts in deciding new cases and evaluating precedents.

A predominantly formal taxonomy facilitates legal analysis and communication. A functional taxonomy can assist those who make and apply law by providing a purposive overview of the field. Reason-based taxonomy may be useful to lawmakers but is unhelpful when offered as a guide to adjudication of disputes.
Given my biases I'm less interested in taxonomy generation for knowledge discovery (ie retrieval of what's been 'filed') and more interested in the construction of categories, although there's a dynamic involving identification of classes (eg the living/dead dichotomy implicit in the preceding post), identification of relationships between those classes, tagging of entities according to those classes and action on the basis of those tags, action that on occasion leads to reconstruction of the classes by the tagged or the taggers. Gadamerian hermeneutic circle, anyone?

Sherwin states
In recent years, a number of scholars in the United Kingdom and elsewhere have turned their attention legal taxonomy , debating how best to organize and classify the common law.  To some extent, taxonomy inevitably plays a role in legal analysis: to think intelligently about law, one must sort legal rules and decisions into categories and generalize about fields of law. For English taxonomers, however, classification of the common law is not simply an incidental task but an independent theoretical project, important in its own right.
The U.K. debate over legal taxonomy grew out of a wave of scholarship on the subjects of restitution and unjust enrichment.  A significant portion of this work focused not on the content of particular legal rules but on how the law of restitution should be organized and what place it occupies within the larger picture of private law. Is restitution a category of substantive law, on a par with tort or contract, or is it a set of remedies? Does unjust enrichment as a ground for relief cut across the fields of private law, or is it confined to cases in which tort and contract law do not support a claim? This line of inquiry led in turn to broader efforts to categorize the whole of private law.
Perhaps the best known legal taxonomer is Oxford’s late Regius Professor Peter Birks. Birks’s master project is a “map” of the common law based on the Institutes of Justinian. Birks’s classification begins at the highest level of generality with a division between public and private law. Birks then divides private law into the law of persons, the law of rights, and the law of actions; and further divides rights into property rights and obligations between parties. Next, he sorts obligations according to the different “causative events” that give rise to them and alternatively according to the different remedial outcomes associated with obligations, such as compensatory damages or restitution of gains.
For Birks, this framework yielded various taxonomic insights. For example, Birks argues that it is a mistake to speak of “tort, contract, and restitution” as the pillars of law. Tort and contract are “causative events” for rights, while restitution is an outcome common to various rights; therefore the classification “tort, contract, and restitution” is “bent.”  Accordingly, Birks insists that the correct series of causative events must be “tort, contract, unjust enrichment, and other events,” with “restitution, compensation, punishment, and other goals” cutting across them as the outcomes of legal claims.  Birks also takes the view that the categories of law must not overlap. For example, “unjust enrichment” cannot include enrichment attributable to “wrongs,” because unjust enrichment and wrongs are discrete categories of causative events.
Birks’s project sparked a variety of criticisms, not only by those who dis- agreed with the particulars of his scheme but also by those who rejected his overall approach to classification of law. Birks’s critics view his taxonomy as formalistic and pointless because it lacks normative content. Some of these critics argue that legal classification must be attuned to the social and economic background in which laws operate.  Others propose that legal classification should track the justifications for legal rules.
American scholars have shown little interest in comprehensive taxonomy of law in the manner of Birks.  Lawyers, judges, and legal scholars constantly engage in taxonomy, sorting the law into classes as they discuss and apply it. Treatises, textbooks, and Restatements often posit or assume fairly systematic taxonomies within fields of law. Large-scale doctrinal essays may also be consciously styled as contributions to the taxonomy of law; some well-known examples are Warren and Brandeis’s article identifying interference with privacy as a type of tort and Fuller and Purdue’s article classifying the interests that may be harmed by a breach of contract.  Nevertheless, the debate surrounding Birks’s taxonomic work has gone largely unnoticed in the United States, perhaps because legal taxonomy appears to have little practical consequence.
In this essay, I examine several different approaches to legal taxonomy. The principal contending methods of legal classification are formal classification of legal doctrine based on logical relations among legal rules; function-based classification based on the social roles of legal rules, and reason-based classification based on common rationales underlying legal rules and decisions. These different possible approaches to classification serve different purposes and range widely in their ambitions to guide and constrain judicial decision-making.
I begin with a brief taxonomy of legal taxonomy, in which I pose three questions about the enterprise of classifying law. First, what is the subject matter to be classified? Second, what are the criteria for classification? Third, what are the purposes of legal classification? I address these questions in the order just presented, although the classifier’s purpose often limits or deter- mines both the choice of subject matter and the criteria for classification. To illustrate the different approaches I identify, I return briefly in the final section to the problem of unjust enrichment, which has occupied such a central role in English legal taxonomy