Cases and Dialectical Arguments - An Approach to Case-Based Reasoning

Case-based reasoning in the law is a reasoning strategy in which legal conclusions are supported by decisions made by judges. If the case at hand is analogous to a settled case, then by judicial authority one can argue that the settled case should be followed. Case-based reasoning is a topic where ontology meets logic since one’s conception of cases determines one’s conception of reasoning with cases. In the paper, it is shown how reasoning with cases can be modelled by comparing the corresponding dialectical arguments. A unique characteristic thereby is the explicit recognition that it is in principle contingent which case features are relevant for case comparison. This contigency gives rise to some typical reasoning patterns. The present work is compared to other existing approaches to reasoning by case comparison, and some work on legal ontologies is briefly discussed regarding the role attributed to cases.