Why did St. Augustine support limited government coercion against the Donatists?

St. Augustine’s support for the use of state coercion against the Donatists was rooted in his efforts to resolve a long-standing schism that had divided North African Christianity for over a century.12

As a leader of the orthodox church, Augustine applied his influence to stimulate resolute action against the Donatist movement, which he viewed as a threat to the unity of the church. His theological and political approach involved:2

• Establishing Church-State Cooperation: Augustine developed a theory regarding the right of orthodox Christian rulers to utilize the power of the state to address heretics and schismatics. He envisioned a relationship where the church and the state could deliberately use one another to achieve their respective ends.21
• Promoting Religious Unity: Augustine argued for the necessity of a universal church against the local particularism represented by the Donatists. He sought to end the division that had persisted since 312, eventually leading to an imperial commission and a conference in 411 that formally condemned the Donatist position.123
• Enforcement of Laws: Following the condemnation of the Donatists, Augustine advocated for the enforcement of laws that denied them civil and ecclesiastical rights, which ultimately broke the movement's strength as a powerful force in the region.23