There cannot be any hard and fast rules. But there can be suggestions and useful analogies. The most useful, to my mind, is that of the difference between the English and French judicial systems. In England (and America), the task of the court in criminal cases, which it devolves upon a jury, is to arrive at a verdict of 'guilty' or 'not guilty' on the evidence presented by prosecuting and defending counsel in turns. Trials are conflicts and verdicts are decisions; the two sides 'win' or 'lose'. In France, and other countries which observe Roman Law, the task of the court in a criminal case is to arrive at the truth, as far as it can be perceived by human eyes, and the business of establishing the outlines of the truth falls not on a jury, which is strictly asked to enter a judgement, but upon a juge d'instruction. This officer of the court, unknown to English law, is accorded very wide powers of interrogation-of the suspect, his family, his associates-and of investigation-of the circumstances and scene of the crime-at which the suspect is often required to participate in a reconstruction. Only when the juge is satisfied that a crime has indeed occurred and that the suspect is responsible will he allow the case to go forward for prosecution. The character of these two different legal approaches is usually defined as 'accusatorial' (English) and 'inquisitorial' (French) respectively.