Letter 54: Also called Book I of Replies to Questions of Januarius. To His Beloved Son Januarius, Augustine Sends Greeting in the Lord. 1.

Augustine of HippoUnknown|c. 395 AD|augustine hippo
barbarian invasionfamine plaguegrief deathproperty economicsslavery captivitytravel mobility
Barbarian peoples/invasions; Church council; Travel & mobility

Augustine to Januarius, greetings.

Your letter raises questions about the diversity of practices among different churches — why some fast on certain days and others do not, why some observe certain ceremonies and others omit them, and what a conscientious Christian should do when confronted with these differences.

These are excellent questions, and I am going to answer them at some length because the principles involved have wide application.

The first principle is this: whatever is commanded in Scripture binds all Christians everywhere. There is no room for variation on matters that God himself has settled. Baptism must be performed. The Eucharist must be celebrated. The commandments must be obeyed. These things are not negotiable.

The second principle is equally important: whatever is not commanded in Scripture but has been established by the practice of the universal Church — that is, the Church spread throughout the whole world — should also be observed, because the universal consent of the faithful, guided by the Holy Spirit over time, carries enormous weight. When the whole Church agrees on a practice, it is not merely a human tradition but the work of divine providence acting through the community of believers.

The third principle is where the difficulty lies: when practices vary from region to region, and neither Scripture nor universal tradition settles the question, the Christian should follow the custom of the local church where he finds himself. This is what Ambrose taught my mother Monica when she was perplexed about Saturday fasting: "When I am in Rome, I fast on Saturday. When I am in Milan, I do not. Follow the practice of the church where you are."

This is not relativism. It is humility. It recognizes that the Holy Spirit works through communities, not just through individuals, and that a lone Christian who insists on his own practice against the custom of the church he is visiting is putting his private judgment above the discernment of the Body of Christ.

Do not let these differences scandalize you, brother. The Church is not weakened by diversity in matters of practice — it is weakened by schism over matters of practice. The one who fasts on Saturday and the one who does not may both be serving the Lord with a clear conscience. The one who breaks communion over fasting is serving only himself.

Farewell.

[Context: This letter, along with Letter 55 (to the same Januarius), became one of Augustine's most influential treatments of the relationship between Scripture, tradition, and local custom. The principle he articulates — that Scripture binds absolutely, universal tradition binds strongly, and local customs should be respected in humility — became a foundational framework for how the Western church handled liturgical diversity for centuries.]

Modern English rendering for readability. See the 19th-century translation or original Latin/Greek for scholarly use.

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