Indonesian political thinking is divided in two: political Islam and secular politics. Soekarno and Mohammad Natsir were dominant political figures in Indonesia, with the former being a secular nationalist, and the latter being an Islamist. Both these leaders inherited ideological disparities, and these distinctions separate political Islam from secular nationalism. This presents an academic opportunity, because such a phenomenon can act as material for research to invent and develop new ideas. This study took a qualitative approach and used both primary and secondary data sources, and a collection of publications and documents were examined to inform this research. The primary and secondary data were therefore analyzed qualitatively to construct a theory. Due to the national arguments during the early years of independence, both Islamic and secular nationalist ideologies emerged. Soekarno and Muhammad Yamin's version of Pancasila (the Five Basic Principles) was advocated as the national principle by the nationalist circle. This ideological issue has been debated since the presidential decree legalized the Jakarta Charter, which established an ideal constitutional vision for the country and state. As a result, the Jakarta Charter was implemented in law as part of the 1945 Constitution.