1. Code of Canon Law (C.I.C.)
The Synod of Bishops was established by St Paul VI on 15th September 1965 with the Motu Proprio Apostolica Sollicitudo. It is a document issued on the exclusive initiative of the Pope. The provisions of this apostolic letter have been accepted in canons 342-348 of the new Code of Canon Law.
Can. 342 The synod of bishops is a group of bishops who have been chosen from different regions of the world and meet together at fixed times to foster closer unity between the Roman Pontiff and bishops, to assist the Roman Pontiff with their counsel in the preservation and growth of faith and morals and in the observance and strengthening of ecclesiastical discipline, and to consider questions pertaining to the activity of the Church in the world.
Can. 343 It is for the synod of bishops to discuss the questions for consideration and express its wishes but not to resolve them or issue decrees about them unless in certain cases the Roman Pontiff has endowed it with deliberative power, in which case he ratifies the decisions of the synod.
Can. 344 The synod of bishops is directly subject to the authority of the Roman Pontiff who:
1/ convokes a synod as often as it seems opportune to him and designates the place where its sessions are to be held;
2/ radios the election of members who must be elected according to the norm of special law and designates and appoints other members;
3/ determines at an appropriate time before the celebration of a synod the contents of the questions to be treated, according to the norm of special law;
4/ defines the agenda;
5/ presides at the synod personally or through others;
6/ concludes, transfers, suspends, and dissolves the synod.
Can. 345 The synod of bishops can be assembled in a general session, that is, one which treats matters that directly pertain to the good of the universal Church; such a session is either ordinary or extraordinary. It can also be assembled in a special session, namely, one which considers affairs that directly pertain to a determinate region or regions.
Can. 346 §1. A synod of bishops assembled in an ordinary general session consists of members of whom the greater part are bishops elected for each session by the conferences of bishops according to the method determined by the special law of the synod; others are designated by virtue of the same law; others are appointed directly by the Roman Pontiff; to these are added some members of clerical religious institutes elected according to the norm of the same special law.
§2. A synod of bishops gathered in an extraordinary general session to treat affairs which require a speedy solution consists of members of whom the greater part are bishops designated by the special law of the synod by reason of the office which they hold; others are appointed directly by the Roman Pontiff; to these are added some members of clerical religious institutes elected according to the norm of the same law.
§3. A synod of bishops gathered in a special session consists of members especially selected from those regions for which it was called, according to the norm of the special law which governs the synod.
Can. 347 §1. When the Roman Pontiff concludes a session of the synod of bishops, the function entrusted in it to the bishops and other members ceases.
§2. If the Apostolic See becomes vacant after a synod is convoked or during its celebration, the session of the synod and the function entrusted to its members are suspended by the law itself until the new Pontiff has decided to dissolve or continue the session.
Can. 348 §1. The synod of bishops has a permanent general secretariat presided offer by a general secretary who is appointed by the Roman Pontiff and assisted by the council of the secretariat. This council consists of bishops, some of whom are elected by the synod of bishops itself according to the norm of special law while others are appointed by the Roman Pontiff. The function of all these ceases when a new general session begins.
§2. Furthermore, for each session of the synod of bishops one or more special secretaries are constituted who are appointed by the Roman Pontiff and remain in the office entrusted to them only until the session of the synod has been completed.
2. Code of canons of Oriental Churches (C.C.E.O.)
Can. 46 §1. In exercising his office (munus) the Roman Pontiff is assisted by the bishops who aid him in various ways and among these is the synod of bishops; moreover the cardinals, the Roman curia, pontifical legates and other persons and various institutes assist him according to the needs of the times; all these persons and institutes carry out the task committed to them in his name and by his authority for the good of all the Churches, accordingto the norm of law established by the Roman Pontiff himself.
§2. The participation of patriarchs and other hierarchs who preside over Churches sui iuris in the synod of bishops is regulated by special norms established by the Roman Pontiff.