This text examines ontology as the science of being as being (ON hÉ ON). The author proposes a terminological distinction between an "entity" (jsoucno) and its "being" (jsoucí). A central theme is the definition of a true entity as an internally unified event unfolding in time. This distinguishes a genuine being from a mere "heap," which lacks internal integration and thus cannot truly be said to "be." Since every temporal entity is never fully present in its entirety—it is always partly what it is not—it cannot be fully comprehended through the category of being alone. The author argues that to grasp a temporal whole, ontology must work in close conjunction with meontology, the study of non-being (TO MÉ ON). Together, these two should form a single discipline capable of reflecting the dynamic, event-like nature of reality, where being and non-being are inextricably linked. Only this integrated approach allows for the conceptual grasp of an entity's temporal integrity and its true essence.