2.
As to the question on which you wish my opinion, "whether it is lawful to fast on the seventh day of the week," 1 I answer, that if it were wholly unlawful, neither Moses nor Elijah, nor our Lord Himself, would have fasted for forty successive days. But by the same argument it is proved that even on the Lord's day fasting is not unlawful. And yet, if any one were to think that the Lord's day should be appointed a day of fasting, in the same way as the seventh day is observed by some, such a man would be regarded, and not unjustly, as bringing a great cause of offence into the Church. For in those things concerning which the divine Scriptures have laid down no definite rule, the custom of the people of God, or the practices instituted by their fathers, are to be held as the law of the Church. 2 If we choose to fall into a debate about these things, and to denounce one party merely because their custom differs from that of others, the consequence must be an endless contention, in which the utmost care is necessary lest the storm of conflict overcast with clouds the calmness of brotherly love, while strength is spent in mere controversy which cannot adduce on either side any decisive testimonies of truth. This danger the author has not been careful to avoid, whose prolix dissertation you deemed worth sending to me with your former letter, that I might answer his arguments.
