This article proposes an integrated legal framework that unifies human rights, animal rights, and the rights of nature within a shared rule-of-law architecture. Drawing on constitutional theory, the legacy of the Magna Carta, and the doctrine of separation of powers, it argues that rights protection is durable only when embedded in enforceable institutional structures. The analysis synthesises constitutional law, governance theory, and environmental jurisprudence to demonstrate how legal standing, access to justice, and independent enforcement can be extended to non-human entities without undermining constitutional stability. The framework is intended to support coherent, preventive, and accountable governance in the context of systemic social and ecological risk.