The lack of ontological pluralism in International Relations has been a strong determinant of the general scope of the discipline and its objects of study, as well as all that is rendered irrelevant to the study of the "international". IR has marginalized difference not only by disciplining epistemologies, but also by rejecting other ontologies, particularly those which belong to indigenous peoples, by relegating them to the realm of myths, legends and beliefs. The roots of ontological marginalization are deeply seeded, so much so that they are present in virtually every field of science (social or not). In order to understand this concern with ontology, we need to refer to the modern age, specifically its Western and now liberal manifestations. The main objective of this article is to put the ontological question on the table. It is argued that the "truth" of one-world, one reality and one universe is also a myth, showing how it has hidden many worlds and many realities. The concept of the pluriverse is used to show how - from different ontological positions, particularly relational cosmovisions like the Andean worldview -, alternatives actually appear. The text is divided into three parts: the first one depicts the pluriverse and what it implies and enables, the second describes how the pluriverse has been occulted by the myth of modernity, and the third part is an attempt to illustrate how relational ontologies contribute to the theoretical constitution of the global.