(B) Causation and attribution

Perhaps, though, even more important in understanding the relationship between liability for things and liability for defective products in French law is the role of causation in attributing liability for a thing under article 1384 alinéa 1. Here, I wish to start by making four preliminary observations.

First, French lawyers and French courts have not in general shown a taste for the development or application of grand theories of causation, in contrast to their German counterparts.¹²¹ Although there is some discussion in la doctrine of the various theories which have been advanced—equivalence of conditions, ‘adequate causation’, theories of risk—most writers are content to conclude that no one theory is (p.55) reflected in the positive law,¹²² even though on occasion the courts have adopted the terminology of one or the other theory to describe the results which they have reached.

Secondly, and clearly related to this, the purposes for which a causal relationship needs to be established vary considerably even within the private law of obligations,¹²³ and while there is an attempt to treat causation generally in the treatises, its treatment in the cases reflects these different purposes. The courts’ general position is found in relation to the causal connection required to exist between a defendants fault and a claimants harm for the purposes of articles 1382 and 1383 of the Civil Code and here there is a rich jurisprudence relating to the classic problems of causation, for example, multiple causes or the ‘loss of a chance’.¹²⁴ However, particularly difficult questions have arisen in relation to liability for the ‘deeds of things’ for where responsabilité is based on fault, issues of causation and fault tend to merge,¹²⁵ but where liability is divorced from fault, more weight is thrown on causation. As we shall see, this is particularly true of the liability for the ‘deeds of things’.

Thirdly, the Cour de cassation in general leaves the interpretation and assessment of evidence (les éléments de preuve) to the lower courts,¹²⁶ but ‘exercises its control with the view to verifying whether the facts found by the juges du fond are to be characterised as establishing the existence or the absence of a causal relationship’,¹²⁷ this including cases where they have ‘denatured’ the terms of the expertise,¹²⁸ where their reasoning is considered unsound,¹²⁹ or simply in order to review their interpretation of the evidence on the ground that they have ‘not deduced the proper consequences from their findings’.¹³⁰ On the other hand, as Carbonnier observes, an element of judgment is inevitable because a claimant’s harm often possesses many causes between which a choice must be made and so the courts proceed ‘empirically’.¹³¹

Fourthly, in principle a claimant bears the burden of proof as to the causal relationship between his harm and the defendant’s act, but the Cour de cassation has sometimes allowed the use of presumptions, which are particularly important in situations where the full sequence of events or their explanation is not clear. Unfortunately, it is sometimes unclear whether or not a person subject to a presumption is entitled to rebut it.