The APS framework defines living systems as agential, processual, and scale-dependent entities that persist and evolve by coordinating internal and environmental processes across time and space.
This statement captures the central intuition of the framework by bringing together its three core explanatory perspectives. Living systems are agential because they actively regulate conditions affecting their continued existence, processual because continuity is maintained through ongoing activity rather than static structure, and scale-dependent because persistence emerges through interactions distributed across spatial, temporal, organisational, and functional domains.
APS therefore approaches life not as a collection of objects that happen to change, but as a dynamic architecture of viability-oriented organised persistence sustained through continual transformation. Development, adaptation, repair, learning, ecological interaction, and evolution are all expressions of this broader organisational reality.
Agency, process, and scale are not independent features added to life. They are complementary perspectives on the same phenomenon, revealing how living systems remain possible despite continual change while maintaining continuity across time and space.