APS Box — What Is Explanatory Grammar?

Explanatory grammar refers to the structured set of conceptual relations that determine what counts as an adequate explanation within a domain.

In APS, explanatory grammar does not begin with a list of entities, but with the conditions under which biological systems can be made intelligible. It specifies how concepts such as agency, process, and scale must be coordinated in order to explain living systems coherently.

Explanation is therefore not simply the identification of causes or mechanisms. It involves situating phenomena within an organised framework that accounts for how systems persist, regulate their activity, and maintain their organisation across time and scale.

Explanatory grammar does not merely organise explanations; it shapes what is taken to be explanatorily relevant. What counts as an entity (e.g., gene, cell, organism, process), what counts as a cause (e.g., mechanism, selection, constraint, agency), and what is treated as a real feature of biological organisation depend on the grammar through which systems are rendered intelligible. In APS, this grammar is oriented toward viability-sustaining, constraint-closed organisation, and thus privileges processes and relations that contribute to persistence as explanatorily primary. This does not determine what exists, but it determines what becomes visible, stable, and tractable within explanation.

Explanatory grammar functions as a constraint on explanation. Accounts that omit agency, ignore temporal continuity, or fail to address scale may succeed locally, but remain incomplete. APS provides a way of identifying these limitations and integrating partial explanations into a more coherent structure.

In brief: explanatory grammar determines how biological explanation works—and, in doing so, shapes what counts as an entity, a cause, and a legitimate target of explanation.