This study examines the definition of ontology as a specific philosophical sub-discipline, drawing upon Aristotle's foundational framework established at the beginning of Book IV of the Metaphysics. The author explores the concept of ontology as the inquiry into "being as being" and critically analyzes the implications of the copula "is." If existence is interpreted strictly as "being now," ontology becomes a field that cannot address "being as a whole" in terms of its temporal progression. Instead, it focuses on entities isolated from their inherent temporality and removed from the overall flow of time. The text suggests that by focusing on the present moment, traditional ontology neglects the past and future dimensions of existence. Consequently, this approach results in an abstraction that separates being from its chronological context. This reflection highlights the inherent limitations of a purely ontological perspective when it fails to account for the temporal entirety of being, thus raising important questions about the scope and methodology of metaphysical inquiry.