This work defines the Stable Authority Boundary (SAB)—a design invariant governing when autonomous and distributed systems are permitted to act, refuse, or remain silent under uncertainty.Rather than optimizing for uptime or performance, the work frames authority contraction and designed refusal as safety invariants—explicit conditions under which systems behave correctly by declining action when authority boundaries are exceeded or context becomes indeterminate. The dissertation argues that many catastrophic and silent failures in modern autonomous infrastructure arise not from insufficient capability, but from misplaced authority, ambiguous responsibility, and the absence of explicit refusal mechanisms. Rather than optimizing for uptime or performance, the work frames authority contraction and designed refusal as safety invariants—conditions under which systems behave correctly by declining action when boundaries are exceeded or context becomes indeterminate. The analysis is grounded in systems engineering practice and draws on examples from distributed computing, infrastructure resilience, and autonomous control. Emphasis is placed on governance, boundary enforcement, and failure behavior rather than algorithmic novelty. This dissertation was completed independently as a practice-based D.Eng work and is shared publicly for transparency, critique, and scholarly discussion. It has not undergone formal peer review. This work consolidates and extends a series of prior technical position papers on authority boundaries, refusal, and resilience in autonomous systems. Keywords: Stable Authority Boundary (SAB), authority contraction, refusal as safety invariant, autonomous systems, distributed systems, failure modes, silent failure, system boundaries, authority boundaries, autonomous systems governance, authority limitation, safety invariants, refusal as safety behavior, system legitimacy, governance-first autonomy, execution authority, system authority, AI systems safety, distributed autonomous systems, resilience engineering, fail-safe design, refusal as safety behavior, system boundaries, authority vs control, governance-first autonomy, trustworthy autonomy, autonomous decision-making, failure modes. #EngineeringSeams #Authority #DecisionBoundaries #Refusal #Silence #Compliance #Auditability #DistributedSystems #AutonomousSystems
David Forbes (Mon,) studied this question.