This text explores the historical evolution and a new conceptualization of the term "subject." Etymologically, it traces the Latin term "subiectum" back to the Greek "hypokeimenon" (that which lies beneath), a term that evolved from grammar to philosophical notions of substrate or substance. The author proposes a novel understanding of the subject as a unique entity characterized by both an external aspect, which is traditionally studied by science, and an internal aspect (inwardness). This inwardness should not be confused with mere subjectivity or the psyche; rather, it acts as the guarantor of the subject's integrity, viewed as a "true event." Subjects manifest at various levels of complexity, where maintaining integrity becomes increasingly difficult at higher levels. A defining feature of this inwardness is its predominantly non-objectifiable nature, which nonetheless remains intrinsically linked to an external, objectifiable side. This duality provides a framework for understanding the subject's existence across different ontological levels.