As formulated in the Preamble to the 1945 Constitution, Pancasila represents the core values agreed upon during the meetings of the Body of Investigators for Preparatory Efforts for Indonesian Independence and the Preparatory Committee for Indonesian Independence. These values were subsequently adopted as the Foundation of the Indonesian State. However, the question persist regarding whether Pancasila can be considered as the grundnorm within Hans Kelsen’s framework in his pure theory of law. This study finds that the grundnorm, as the highest source of legal obligation, is accepted as a necessity by individuals as a necessity through their free will and is inherently perceived as true. It exists in the practical reason of each individual, is a priori, and is never formalized through state processes. Pancasila, although fundamental, cannot be equated with the grundnorm as its authority as the source of all state laws derives not from its content but from its formal declaration by legislative and executive bodies. Despite this, Pancasila serves as a unifying foundation that reconciles differences in ethnicity, race, and religion, ensuring Indonesia’s sustainable existence, transcending merely being a source of legal obligation.