Augustine in His Own Words (continued)
The Bishop 89 plenary councils whose authority is well founded in the Church. Examples are the annual commemorations of the Lord's Passion, Resurrection, and Ascension into heaven, the descent of the Holy Spirit from heaven, and other such observances as are kept by the universal Church wherever it is found.
(2.2) Other customs, however, differ according to country and locale. For example, some fast on Saturday, others do not; some receive the Body and Blood of the Lord daily, others receive it on certain days; in some places no day is omitted in the offering of the Holy Sacrifice; in others it is offered only on Saturday and Sunday, or even only on Sunday; and other such differences may be noted. There is freedom in all these matters, and there is no better rule for the earnest and prudent Christian than to act as he sees the Church act wherever he is staying. What is proved to be against neither faith nor morals is to be considered optional and is to be observed with due regard for the group in which one lives.
(2.3) I believe you heard this [anecdote] some time ago, but let me nevertheless repeat it here: My mother, who had followed me to Milan, found that the church there did not fast on Saturday. She began to be anxious and uncertain as to what she should do. I was not concerned then with such things, but for her sake I consulted on this matter that man of most blessed memory, Ambrose. He answered that he could teach me nothing except what he himself did, because, if he knew anything better, he would do it. When I thought that he wished to impose his views on us, solely on his own authority, without giving any reason, he followed up and said to me: "When I go to Rome, I fast on Saturday, but here I do not. You should follow the custom of whatever church you attend if you do not want to give or receive scandal." When I told this to my mother, she willingly accepted it. And recalling this advice over and over again, I have always esteemed it as something given by a heavenly oracle. For I have often experienced with grief and dismay that the weak are deeply disturbed by the aggressive obstinacy or superstitious fears of certain brethren who stir up such controversial questions that they think nothing is right except what they themselves do. And these are things of such sort that they are not prescribed by the authority of Holy Scripture nor by the tradition of the universal Church, and they serve no good purpose of amending one's life, but they are insisted on simply because somebody thinks up a reason for them, or because someone was accustomed to do so in his own country, or because he saw things done somewhere on a pilgrimage, and he esteemed them to be more correct because they were further from his own usage.18
18. Ep. 54.1.1–2.3 (CCL 31:226–28); trans. Parsons, FOTC 12:252–54 (modified). Augustine mentions this incident also in ep. 36.14.32 (CCL 31:153).