Conventional framing
Reductionism is commonly understood as the view that complex systems can be explained by analysing their constituent parts and the laws governing those parts. In biology, this often takes the form of explaining organisms in terms of genes, molecules, and biochemical mechanisms, with the assumption that higher-level phenomena can be derived from lower-level processes.
This framing typically treats ontological fundamentality—what is most basic in reality—as determining explanatory priority, and assumes that biological organisation, function, and adaptation can be reduced without remainder to physical and chemical descriptions.
APS reframing
APS accepts that biological systems are materially constituted by physical and chemical processes but rejects the inference that material constitution alone determines explanatory priority. Explanation in biology concerns not only what systems are made of but what makes them intelligible as living systems.
This limitation reflects a broader orientation of explanation in which analytic direction—explaining systems in terms of their components—is treated as explanatorily primary (see Analysis, Synthesis, and the Direction of Explanation).
In APS, biological intelligibility begins with viability-oriented, constraint-closed organisation. Components such as genes, enzymes, and structures acquire biological meaning only through their contribution to sustaining the organisation of the system in which they participate. Outside this context, they remain physically real but are not yet biologically explanatory.
Reductionism is therefore reframed as incomplete rather than incorrect: it captures the material basis of biological systems but omits the organisational conditions required for biological intelligibility.
Key Point
Reductionism in APS is limited by the distinction between material constitution and explanatory priority: biological systems are physically constituted by parts, but their explanation depends on the organisation those parts collectively sustain.