APS distinguishes Moral Legitimacy from viability, persistence, popularity, legality, authority, success, consensus, and social stability.
A practice may persist while remaining morally objectionable. A law may be legally valid while lacking moral legitimacy. An institution may be stable, effective, or widely accepted without being morally justified.
Moral Evaluation investigates these questions by examining standing, vulnerability, treatment, responsibility, affectedness, justification, and legitimacy.
Viability ≠ Moral Legitimacy
Persistence ≠ Moral Legitimacy
Consensus ≠ Moral Legitimacy
Moral Legitimacy therefore concerns whether organised conduct can be justified rather than merely explained.