Research on the notion of causality.

Summary The concept of causation has two different aspects in liability law. On the one hand, it makes it possible to formulate an explanation for past events. On the other hand, it constitutes an attribution to a responsible person of the burden of answering for these facts. These two functions must guide the interpretation of the notion. The explanatory dimension of causality leads the interpreter to two different modes of definition. The first is to rely on scientific conceptions of the notion of causality. From this point of view, causality is defined as an invariable or highly probable regularity, which leads to the criterion of probability defended by the theory of adequate causality. One can try to go beyond the idea of ex ante probability by relying on the criterion of the sine qua non condition, which implies counterfactual reasoning. The second mode of definition, defended by two English authors, Hart and Honoré, seeks to build the legal interpretation of causality on the usual meanings of the notion in everyday language. Whatever the point of view considered, it is the criterion of causality sine qua non that seems to impose itself. But it is necessary to add considerations of imputation to it. The attributive dimension of causality leads to an analysis that is no longer conceptual but functional. In this respect, causality constitutes a condition that makes it possible both to adopt liability in principle and to determine the extent and burden of reparation. In this context, as a legal concept responsible for imputing liability, the qualification of causality may depart from the strict logic of causal explanation. The dual nature, descriptive and imputative, of causality in liability must guide its qualification. This must be done in the form of an argumentative debate mobilizing elements relating to the factual circumstances and considerations of legal policy. [Author's summary].