Individuation.

The one-sentence version

Individuation is the achievement by which a system acquires an individual nature—a bounded, distinct, persistent identity—rather than remaining a pure gradient or field. It is not a prior given but a sustained accomplishment.

Where the term comes from

The concept originates in Simondon’s L’Individuation à la lumière des notions de forme et d’information, where individuation is the process by which pre-individual potentiality crystallizes into individuated actuality. Ontogony radicalizes this: individuation is never complete; it requires continuous constraint-maintenance.

Why it matters

The question “what is an individual?” is the question “what is a closure?” and this diagram shows why closure persists only through the sustained work of constraint-maintenance across all four registers.