Article 17 1. No member of the Court may act as agent, counsel, or advocate in any case. 2. No member may participate in the decision of any case in which he has previously taken part as agent, counsel, or advocate for one of the parties, or as a member of a national or international court, or of a commission of enquiry, or in any other capacity. 3. Any doubt on this point shall be settled by the decision of the Court. Article 18 1. No member of the Court can be dismissed unless, in the unanimous opinion of the other members, he has ceased to fulfill the required conditions. 2. Formal notification thereof shall be made to the Secretary-General by the Registrar. 3. This notification makes the place vacant. Article 19 The members of the Court, when engaged on the business of the Court, shall enjoy diplomatic privileges and immunities. Article 20 Every member of the Court shall, before taking up his duties, make a solemn declaration in open court that he will exercise his powers impartially and conscientiously. Article 21