Description This work develops a contemporary doctrine of separation of powers reframed as a functional and resilience-based constitutional system. It argues that classical tripartite separation is insufficient to address modern systemic risks such as welfare failure, economic fragility, privatisation of essential services, environmental degradation, and global interdependence. The article introduces two constitutional counterparts within The Liberty System: the People’s counterpart, requiring enforceable guarantees of welfare, dignity, and civil liberties, and the Economic counterpart, requiring fiscal solvency, sustainability, and long-term economic stability. Rather than relying primarily on litigation, the framework emphasises institutional design, decentralised accountability through parish-level governance, and judicial review as a stabilising mechanism. Drawing on comparative constitutional models (including the UK, EU, South Africa, Canada, India, and the United States), the work addresses the risks of fused powers, privatisation, and executive dominance, and proposes buy-back sovereignty as a resilience option. The paper further situates separation of powers within a global governance context, outlining readiness for data-driven and quantum-enabled accountability while remaining grounded in civil liberties traditions rooted in the Magna Carta. The doctrine is presented as a scalable constitutional framework capable of operating across local, national, and global governance systems, integrating human, animal, and environmental protection with economic sustainability.