Decision 15 G.R. No. 221139 aims to "preserve and develop their cultures, traditions, and institutions." 58 It elevates to the level of constitutional text terms such as "ancestral lands" and "customary laws." Because the Constitution is the "fundamental and organic law of the land," 59 these terms' inclusion in the Constitution renders them integral to the Republic's being. Through the same inclusion, the State manifestly assents to the distinctiveness of indigenous peoples, and undertakes obligations concomitant to such assent. With the 1987 Constitution in effect, the Indig1~nous Peoples' Rights Act was adopted precisely recognizing that indigenous peoples have been "resistan[t] to political, social[,] and cultural inroads of colonization, nonindigenous religions and cultures, [and] became historically differentiated from the majority of Filipinos."60 Among the Indigenous Peoples' Rights Act's provisions on selfgovernance and empowerment is Section 15: SECTION 15. Justice System, Conflict Resolution Institutions, and Peace Building Processes. - The ICCs/IPs shall have the right to use their own commonly accepted justice systems, conflict resolution institutions, peace building processes or mechanisms and other customary laws and practices within their respective communities and as may be compatible with the national legal system and with internationally recognized human rights. (Emphasis supplied) Section 15 limits indigenous peoples' "right to use their own commonly accepted justice systems, conflict resolution institutions, peace building processes or mechanisms and other customary laws and practices[.]" It explicitly states that this right is applicable only "within their respective communities" and only for as long as it is "compatible with the national legal system and with internationally recognized human rights." It is a basic rule of statutory construction that "courts have to take the thought conveyed by the statute as a whole; construe the constituent parts together; ascertain the legislative intent from the whole act; consider each and every provision thereof in the light of the general purpose of the statute; and endeavor to make every part effective, harmonious[,] and sensible." 61 Section 65 ought not be read as an all-encompassing, unqualified authorization. Rather, it must be viewed within the confines of how it is a 58 59 CONST., Art. XIV, sec. 17. J. Francisco, Concurring and Dissenting Opinion in Aquino v. Commission on Elections, G.R. No. 120265, September 18, 1995, 248 SCRA400, 438 [Per J. Kapunan, En Banc]. 60 Rep. Act. No. 8371 (1997), sec. 3 (h). 61 Fort Bonifacio Development Corporation v. Commissioner of Internal Revenue, 617 Phil. 358, 367 (2009) [Per J. Leonardo-De Castro, En Banc] citing Republic v. Reyes, 123 Phil. 1035 (1966) [Per J. Sanchez, En Banc]. /