Constitution CANNOT be changed extra-constitutionally (G.R. No. 174153; October 25, 2006)

Rappler posted this photo of a tarpaulin banner in a pro-Duterte "revolutionary government" rally. It says, "We, the sovereign Filipino people[,] grant President Rodrigo Roa Duterte REVOLUTIONARY POWER! Effective November 30, 2017 Mendiola, Manila[.]" It is a fundamental principle that a constitution can only be revised or amended in the manner prescribed by the instrument itself, and that any attempt to revise a constitution in a manner other than the one provided in the instrument is almost invariably treated as extra-constitutional and revolutionary. x x x x "While it is universally conceded that the people are sovereign and that they have power to adopt a constitution and to change their own work at will, they must, in doing so, act in an orderly manner and according to the settled principles of constitutional law. And where the people, in adopting a constitution, have prescribed the method by which the people may alter or amend it, an attempt to change the fundamental law in violation of the self-imposed restrictions, is unconstitutional." (G.R. No. 174153; October 25, 2006)