The Prime Minister and the ministers are appointed and dismissed by Royal Decree (Article 43). Such decrees are also signed by the Prime Minister himself, who signs his own appointment and those of the others (Article 48). Royal decree also institutes the ministries (Article 44), which have tended to be very variable in number and scope, and non-departmental ministers (Subarticle 2), who officially have no ministry but whom in fact is assigned the necessary personnel and who sign and are responsible for a partial budget. The ministers together form the Council of Ministers (Article 45), presided by the Prime Minister (Subarticle 2), which assembles (in fact weekly) to promote the unity of the general governmental policy (Subarticle 3). Though existing since 1823, this council has only been mentioned since the revision of 1983; its constitutional powers as such are almost nil. The proceedings are secret for a period of fifty years. Outwardly the council acts as if there were complete agreement between all ministers: the so-called "homogeneity". By Royal Decree are appointed secretaries of state (Article 46); these are subordinate to a certain minister who is fully responsible for their acts (Subarticle 2). All laws and Royal Decrees have to be countersigned by the responsible minister(s) or secretaries of state (Article 47). The countersign has been mandatory since the revision of 1840. Since 1983 such laws and decrees also have to be affirmed by a signed affirmation; it is usually assumed these acts coincide. All ministers and secretaries of state have to swear an oath of purification (declaring to not having bribed anyone to obtain their office, nor having been bribed to commit certain acts when in office) and swear allegiance to the Constitution (Article 49).