27. Chap. XII.

As to the seventh day of the week there is less difficulty in acting on the rule above quoted, because both the Roman Church and some other churches, though few, near to it or remote from it, observe a fast on that day; but to fast on the Lord's day is a great offence, especially since the rise of that detestable heresy of the Manichaeans, so manifestly and grievously contradicting the Catholic faith and the divine Scriptures: for the Manichaeans have prescribed to their followers the obligation of fasting upon that day; whence it has resulted that the fast upon the Lord's day is regarded with the greater abhorrence. Unless, perchance, some one be able to continue an unbroken fast for more than a week, so as to approach as nearly as may be to the fast of forty days, as we have known some do; and we have even been assured by brethren most worthy of credit, that one person did attain to the full period of forty days. For as, in the time of the Old Testament fathers, Moses and Elijah did not do anything against liberty of eating on the seventh day of the week, when they fasted forty days; so the man who has been able to go beyond seven days in fasting has not chosen the Lord's day as a day of fasting, but has only come upon it in course among the days for which, so far as he might be able, he had vowed to prolong his fast. If, however, a continuous fast is to be concluded within a week, there is no day upon which it may more suitably be concluded than the Lord's day; but if the body is not refreshed until more than a week has elapsed, the Lord's day is not in that case selected as a day of fasting, but is found occurring within the number of days for which it had seemed good to the person to make a vow.