The Principle of Identity as Preserved Coherence Under Change

Across scientific and philosophical domains, identity is often treated as a stable or essential property of systems. At the same time, empirical observation shows that systems continuously change while nevertheless remaining identifiable as the same. This paper addresses this tension by reformulating identity as a structural condition rather than a static attribute. Identity is defined as the preservation of coherence within tolerance limits across successive transformations. Under this formulation, identity does not reside in isolated states, fixed components, or invariant essence. It exists only across sequences of change in which structural relations remain sufficiently preserved. When coherence falls outside tolerance, continuity is lost and identity cannot be maintained. The principle is domain-independent and does not rely on specific mechanisms or ontological commitments about time. Instead, it specifies a general structural condition under which systems can persist as identifiable entities while undergoing change. This formulation is situated within Bellori’s configuration chain framework, in which change, stability, identity, and meaning are treated as structurally ordered conditions. Within this framework, identity arises when stability is maintained across change and provides the basis upon which meaning can be constructed through interpretation. The resulting account shifts identity from a descriptive label to a necessary structural condition for the persistence and recognition of systems under change.