Abstract
This paper rejects the traditional assumption that “life” names a biological category. It demonstrates that life is a mode of continuity grounded in a single operator: response–persistence. A system is living when its responses to conditions endure and constrain its future states. This minimal mechanism is already present in prebiotic chemistry, underwrites biological evolution, structures cognition, and appears in artificial and cosmological systems. By identifying the operator rather than the traits, the paper dissolves the conceptual boundary between living and non‑living systems and exposes the arbitrariness of existing definitions. Life is not a special substance or a privileged domain. It is the simplest possible way a system carries its past into its future.