There is a presumption that the judge knows the law. There is no need, in theory, for the parties to provide him with the materials and information necessary for the decision of questions of law. No similar presumption is possible in relation to questions of fact. Jura novit curia may be plausible; facta novit curia is absurd. Nevertheless, as has been pointed out in a previous chapter, at the end of the day, decisions of fact are as much for the judge as are decisions on the applicable law. It is the purpose of this chapter to examine the way in which French and English law, respectively, deal with the particular problem that is raised when the judge is called upon to decide technical questions, that is, questions of fact which, because of their scientific, technical or technological character, cannot be understood or resolved by a non-specialist without the assistance of an appropriately qualified specialist. Before turning to that, however, it is necessary to say something about the nature of questions of fact in general.

Questions of fact

It is a general principle as much of French as of English law that each party must prove the facts necessary to the success of his claim or defence. Since nothing is literally ‘proved’ in litigation, however, what is meant by the general principle is that the party carrying the burden of proof must discharge it by producing materials - evidence or proofs -which will persuade the judge to decide the issue in his favour.