Biological functions are not merely causal effects. In living systems, processes matter because they contribute differently to the continued persistence of the organism or lineage.
The heart does not merely circulate blood; its activity contributes to maintaining the viability of the organism. Likewise, immune responses, metabolic regulation, and behavioural coordination are biologically significant because they help sustain the organised conditions required for continued existence.
This introduces a form of biological normativity. Some processes contribute positively to persistence, while others undermine or disrupt it. A failing heart, damaged membrane, or dysregulated metabolism is not simply causally different from a successful one, but persistence-relevantly worse for the system itself.
APS therefore understands function and normativity as inseparable aspects of viability-oriented organisation. Functional organisation is normatively structured because living systems must continuously maintain the conditions required for their own persistence.
This normativity is not imposed externally by observers or designers. It emerges from the organisation of living systems themselves. Processes become biologically meaningful insofar as they contribute to or undermine the persistence of the system whose organisation they help sustain.