ARCHITECTURAL REDUNDANCY AS A UNIVERSAL LAW OF SYSTEM RECOVERY: Cross-Domain Convergence Across Neuroscience, Ecology, Immunology, Materials Science, and Network Engineering

Structured Abstract Background Across neuroscience, ecology, immunology, materials science, and network engineering, a fundamental prediction problem persists in each field: given a system before damage and the damage's magnitude, what is the system's recovery trajectory? Each field has invested heavily in characterising what is destroyed. Each field has systematically under-specified what property of the pre-damage architecture determines how the surviving substrate reorganises around the destruction. The result is the same pattern of unexplained variance in every field: identical damage, divergent outcomes. Gap No cross-domain framework has identified this as a structural principle shared across fields, formalised it as a testable universal claim, or derived it from a mathematical foundation. The fields each have domain-specific accounts of what damage does; none has an account of the pre-damage architectural transfer function that determines the ceiling of recovery. Approach We synthesise six independent research programmes — stroke recovery (SRCT), traumatic brain injury (SRCT-TBI), ecological community disturbance (PRAT), acute immune challenge (IRITR), materials damage tolerance (LPTR), and network fault recovery — into a single meta-claim: the Architectural Redundancy Index (ARI) Principle. The ARI Principle states that pre-damage topological redundancy across functionally non-equivalent pathways is an independently significant determinant of post-damage recovery trajectory across all systems where the recovery mechanism is constituted by the same substrate being recovered. Results Six independent empirical anomalies are resolved by a single explanatory principle. The ARI Principle is grounded in the IRM Impossibility Theorem and the IGCDT, which establish that its necessity follows from the categorical structure of self-referentially self-maintaining systems. The domain-specific operationalisations (TRI, FIRI, IRITRI, load-path topology, k-connectivity) are shown to be instances of the same graph-theoretic quantity — k=2 path redundancy across functionally non-equivalent routes — adapted to different substrates. Implications The ARI Principle restructures damage science across all five domains simultaneously: pre-damage architectural measurement should be added as a necessary component of outcome prediction models in stroke rehabilitation, sports medicine, ecological conservation, vaccine design, materials engineering, and network fault management. A single formula governs stabilisation across all domains. Keywords: Architectural Redundancy Index, ARI Principle, topological redundancy, SRCT, PRAT, IRITR, LPTR, k-connectivity, pre-damage architecture, structural reorganisation capacity, recovery ceiling, ALGUILAS-AI, IRM theorem, IGCDT, cross-domain structural invariance Method ALGUILAS-AI Dialectical Engine · Philosophy of Virtues Research Programme, Italy ·