Three Principles of Eudaimonia: The axiomatic foundations of ethics, political science, jurisprudence, game theory, human behavior, institutional design, and global governance.

In a manner analogous to Newton's three laws of motion, this study employs the axiomatic method in its theoretical construction. To address the paradigmatic crisis in contemporary ethics stemming from the "absence of axioms," this paper proposes "Eudaimonist Ethics," which takes "eudaimonia" (human flourishing) as its foundational axiom. The theory first establishes a "Stratified Theory of Eudaimonia" as the psychological basis for behavioral motivation and then rigorously deduces three fundamental principles capable of serving as ethical axioms, namely: 1) Pursue one's own eudaimonia (the factual starting point); 2) Do not infringe upon the eudaimonia of others (the interactive norm); and 3) Jointly construct an environment conducive to eudaimonia (active sublimation). This paradigm systematically derives core normative concepts such as liberty, good and evil, morality, and law, and further reconstructs fundamental political philosophy notions including government, the state, power, and legitimacy—thereby forming a "logically self-consistent, interdisciplinary new paradigm." Research demonstrates that this paradigm not only resolves with internal coherence the classical dilemmas faced by utilitarianism, deontology, and virtue ethics but also, through its formalization as a "Eudaimonic Game" model (incorporating parameters such as the moral sentiment parameter `f`, the social deterrence parameter `w`, and the cooperation dividend parameter `e`), rigorously proves how morally cooperative behavior can emerge as a stable equilibrium within an expanded framework of rational choice. Ultimately, the paradigm contends that the "Three Principles of Eudaimonia" constitute an "operational system of ethical consistency spanning from personal norms to global governance," furnishing a unified normative foundation for individual decision-making, historical diagnosis, institutional design, educational reform, and civilizational evolution. This signifies a paradigm shift in ethics, moving from static rule compliance to dynamic order design, while simultaneously elevating the role of the moral agent from an 'optimal solution player' under given rules to a "co-architect of the future order."