These various congregations become, however, safeguards of truth and freedom, not only by the variety of their faculties, but also by their internal structure and their methods of procedure. Each of them is composed of a cardinal-prefect, of a certain number of cardinals, and a secretary. To this the Congregation of the Holy Office, which is presided over by the pope himself, forms an exception. The prefect is charged with the arrangement of the business of the congregation. He manages the preparation of causes prior to their discussion. He submits them to the examination of his colleagues, and presides at their deliberations. After the debate has terminated, he receives their suffrages and announces their decision. He also examines into those matters which are settled at a private audience with the pope, without being brought before the whole congregation, and his words give publicity to the decisions which he receives from the living voice of the pontiff himself. Finally, he determines alone certain matters of minor importance, which, on that account, are neither brought before the congregation nor the pope. He receives his appointment from the sovereign pontiff, and holds his office during life. When he is absent, his place is supplied by the oldest cardinal of the congregation, and, at his death, the cardinal-secretary of state places his signature to the nomination of the new prefect. The secretary assists at the meetings of the congregations, and is charged with the duty of recording its resolutions and acts, of transcribing its registers, and of delivering its processes. He also summons the cardinals, presents to them at each session a brief of the causes they are to treat, and gives them, for each of these, a succinct statement of the principal arguments of the parties, with a summary of the documents pertaining to them. This statement is printed upon loose sheets and distributed to the cardinals several days in advance, in order that each may have time to fully investigate the affair. Sometimes this statement is prepared by the cardinal-reporter, hence called the _cardinal ponent_. The secretary also submits to the pope the sentences of which he is to approve; and, for this purpose, those of the different congregations have a day of special audience before the pontiff. The faculty of giving licenses for various purposes, such as reading prohibited books, etc., etc., is confided to the secretary; also the power to distribute copies of the decrees of the congregation, authenticated by the signatures of the prefect and the secretary, and sealed with the seal of the congregation, which thus become of valid force before all tribunals, and even elsewhere, if they treat of extra-judicial matters. The secretaries are appointed by the pope himself. They must be bishops, with the title of a church _in partibus infidelium_, or, at least, prelates of the Roman court. In the Congregation of the Holy Office the secretary is a cardinal.