The document defines a constitution as the fundamental law of a state that establishes and limits the powers of government to protect citizen rights. It outlines three types of constitutions: one for liberty, one for government, and one for sovereignty. It also discusses principles for interpreting constitutions such as considering the ordinary meaning of words, the history and circumstances around its framing, and interpreting it as a whole. The Philippine constitution derives its authority from previous organic laws and is the supreme law of the land.