This text explores the definition of ontology as a specific philosophical discipline, distinguishing it from traditional scientific fields sharing the -logy suffix. Although the term is commonly attributed to Christian Wolff, the roots of the discipline trace back to Aristotle, who characterized it as the study of being qua being. The author emphasizes that ontology is not merely a compendium of everything that exists, but requires a deeper critical investigation beyond common sense. A significant shift in the understanding of ontology occurred with Gottfried Wilhelm Leibniz, who expanded the field to include non-being and nothingness. This expansion allows for a distinction between classical ontology and meontology, the latter of which focuses on the aspects of non-being. The text challenges the naive view of the world as a simple aggregate of existing things and invites reflection on the relationship between what is and what is not. In this context, ontology serves as a critical discipline examining the fundamental foundations of reality and the boundaries between existence and void.