The cases decided by the Supreme Court involve several classes of disputes. Most prominently, the Court is called upon to exercise the power of
judicial review of presidential or legislative actions. More often, the Court also undertakes
appellate review of decisions of the trial courts and the
Court of Appeals in civil and criminal cases. The Court is also tasked with deciding administrative cases involving members and employees of the judiciary and of lawyers belonging to the Philippine Bar. The decisions of the Court become part of the law of the land. Each Justice carries one vote on the Court which they exercise whether when sitting in Division, or in the full complement of 15 (or "
en banc"). Since the 1970s, the Supreme Court has sat in three divisions, with five Justices as members of each division. As most Supreme Court cases are decided by the division rather than the en banc, a vote of three Justices sitting in a division is usually sufficient to decide the case. However, the Constitution prescribes instances whereby a case must be decided
en banc, such as in declaring a law as unconstitutional or when a
judicial precedent is overturned. Each vote can be crucial, as recently shown in the 2006
People's Initiative case (
Lambino v. COMELEC), which was decided
en banc by an 8–7 vote. As a case is decided, one justice in the majority is assigned to write the
majority opinion for the Court. Even as these decisions speak in behalf of the Court, the writer of the opinion (known as the "ponente") is strongly identified with the decision, and the body of opinions of each Justice enhances his/her reputation. Many important opinions are analyzed in
law schools and are well-remembered long after the Justice had left the Court. For example, several of the opinions of Associate Justice
Jose P. Laurel were crucial in the development of Philippine jurisprudence and are widely read and quoted nearly 70 years after they had been written. Any other Justice, whether they be in the majority or in the minority, is entitled to write a separate opinion in a case to clarify his/her views, or even to challenge the points raised in the
majority opinion. In the 1973 case of
Javellana v. Executive Secretary, concerning the ratification of the 1973 Constitution, each Justice chose to write a separate opinion, while more recently, the 2005 decision on the Expanded VAT Law (
Abakada v. Executive Secretary) saw 11 separate opinions. The separate opinions of a Justice in the majority is usually known as a "
concurring opinion", while one penned by a Justice in the minority is known as a "
dissenting opinion". A Justice who only partially agrees with the majority opinion while disagreeing with portions thereof may even write a "concurring and dissenting opinion". While these separate opinions do not receive as much public attention as majority opinions, they are usually studied in the legal academe and by other judges. On several occasions, views expressed in a
dissenting or
concurring opinion were adopted by the Supreme Court in later years. Justice
Gregorio Perfecto, whose staunch
libertarian views were out of sync with the
Cold War era, wrote over 140
dissenting opinions in just 4 years. Years after his death, some of his views in dissent, such as in ''Moncado v. People's Court (1948)'' were adopted by a more liberal Supreme Court. ==The rule of seniority==