Dealing reasonably with blurred boundaries

Vagueness and Indeterminacy as a Challenge for Philosophy and Law

Research project within the funding initiative
»Schlüsselthemen der Geisteswissenschaften« (»Key Issues in the Humanities«)
of the Volkswagen Foundation

Blurred Boundaries
We live in a world of blurred boundaries. In nature, continuos transitions are ubiquitous phenomena. Geography distinguishes between different climate zones, biology between different developmental stages, medicine between normal and high blood pressure, engineering science between secure and insecure nuclear power plants, and so on. Yet, every scientist will grant that those distinctions are a matter of degree. At the same time, scientific theories are in need of clear distinctions and precise concepts. However, sharply delineated categories and concepts do not eliminate continuous transitions from the world. When a continuum is divided into different parts, borderline cases and grey areas appear.

Semantic Vagueness
The linguistic counterpart to the problem of blurred boundaries is the problem of semantic vagueness. There are many expressions in natural language whose extensions do not seem to be sharply delineated. Semantic vagueness can cause fallacies and paradoxes. The sorites argument (»Paradox of the heap«), for example, is widely recognised as a fallacy. However, it is a matter of controversy just what the mistake is. A number of theories of vagueness have been developed in philosophy and linguistics which are barely known outside these disciplines.

Vagueness and Indeterminacy in Law
Under the heading of the "indeterminacy of law", semantic and ontological vagueness are regarded as a central methodological problem in jurisprudence. In fact, the problems posed by vagueness and indeterminacy are particularly troublesome in law, as the practice of adjudication is constantly faced with hard cases which the judges are hardly free to leave undecided. It is part of everyday legal practice to apply laws expressed in general terms to specific cases, in order to check whether the elements of statutory definition are ful­filled. However, judges frequently find it anything but clear whether a particular state of affairs still falls under a legal predicate or not. ("Subsumption problem", "legal construction")

Law as bottleneck
Law finds itself dealing with cases from all walks of life: sooner or later, almost every socially relevant question of demarcation ends up as the object of legal adjudication. The law, in other words, is a bottleneck, and the research project places itself at this bottleneck. The manifold ways of dealing with blurred boundaries which we find in legal practice provide us not only with a wealth of empirical case-studies, but also with a touchstone with which to test the theoretical solutions developed in philosophy, linguistics and jurisprudence. Any such solution should work in legal adjudication.

Fields of application
The bottleneck aspect of law is used to tap the project's fields of application, for example:
• Environmental and technology law
In environmental and technology law, threshold values and other regimes decide over the legality of technical devices, for example over admissible levels of emission. The project members dealing with demarcation in environmental and technology law are based in the RWTH Aachen University.
• Health and illness
Is there a continuum between »healthy« und »ill«? This question is connected to a number of questions regarding the payment of health services under social security and insurance law.
• Danger, Risk and Security
In political debates on public security, considerations of risk or danger are frequently meant to legitimise highly controversial security measures. In constitutional law, the standards for legitimate infringements on rights are notoriously fuzzy.

Aims of the project
The research group examines the semantics, ontology and epistemology of vagueness and indeterminacy. It is based on the assumption that the phenomena of vagueness and indeterminacy in different fields of application have similar structures, so that understanding them poses similar theoretical problems and requires similar methods. The theoretical aim of the project is to identify and systematize phenomena of vagueness and indeterminacy in different fields of application. The practical aim is to develop and implement procedures of dealing reasonably with blurred boundaries.

Project chairs
Prof. Dr. Geert Keil
Institut für Philosophie
Humboldt-Universität Berlin

Prof. Dr. Ralf Poscher
Institut für Staatswissenschaft
und Rechtsphilosophie
Universität Freiburg