Conventional framing
Life is commonly defined by lists of traits such as metabolism, growth, reproduction, and homeostasis, or by evolutionary lineage. While these approaches identify important features, they do not specify the organisational principle that unifies living systems or explains why these features matter biologically.
APS reframing
APS defines life as viability-oriented, constraint-closed organisation. Living systems are not identified by a checklist of properties, but by the organisation through which they sustain their own persistence. This organisation establishes intrinsic conditions of viability, evaluates internal and external states relative to those conditions, and reorganises its own constraints in response to perturbation.
The defining threshold of life is reached when organisation becomes normatively structured—when regulation is not merely reactive but evaluative, and when persistence depends on the system’s own activity rather than external control.
Life is not defined by traits—it is the organisation of persistence through biological agency.
Key Point
Life is not defined by traits—it is the organised persistence of biological agency.