Recently a friend of mine was shocked to hear that rather than write a new rule, St. Dominic and the early Dominicans adopted the Rule of St. Augustine to govern their lives. He asked me why they did this. Well, there are two reasons. First, the Fourth Lateran Council in 1215 forbade the writing of new rules. If a new religious order was to be formed, it needed to adopt a rule that was already in use. But this does not explain why St. Dominic and his early companions chose the Rule of St. Augustine. Thus the second reason, simply stated, is that the Rule of St. Augustine was the most fitting for the life to which they felt called.
However, because the Rule of St. Augustine is more of a spiritual treatise than a legislative one, the early friars developed a series of customs (constitutions) by which they could interpret how to live the Rule practically on a day to day basis. To explain more clearly why the Rule of St. Augustine is fitting for an order of preachers, and how the constitutions of the order were drawn from it, Bl. Humbert of Romans, the fifth Master of the Order, wrote a lengthy commentary on the Rule for the brethren. To help those of you discerning with us to see how the Dominican life is related to the Rule of St. Augustine, I will be posting various quotations from Bl. Humbert's Commentary on the Rule of St. Augustine. If you are interested in reading the Rule itself you can find a translation here. And so without further ado, here is what Bl. Humbert has to say concerning the nobility of the Rule of St. Augustine.
On the praise of the rule of St. Augustine (from Blessed Humbert of Romans)
Among the many and various rules under which diverse religious serve the Church, some have been handed down by men who have not been enrolled in the list of saints. Others were written by saints, but such as who were not eminent in wisdom. Still other rules were handed down from saints holy and perfect in wisdom, yet who did not have great authority. Now, it is certain that holiness in the soul of man is sometimes more easily developed by useful opinions than by wisdom. However, though it is holy, sometimes simplicity, if it is not guided by wisdom, is seen as less praiseworthy. Indeed the simple opinions advanced by holy and wise men who lack authority are often less accepted. Therefore, how great and excellent is the dignity of the rule which is discovered to be handed down from a man most holy, most wise, and outstanding in authority, namely the bishop St. Augustine?
Further, in the beginning when religious life began to arise in the Church, there were two kinds of religious, namely hermits and cenobites (i.e. monks who lived in community). After a period of time, St. Benedict, whose rule is greatly revered in the Church of God, wrote a rule after the model of the lives of the early cenobites, which is evident in it what was said explicitly at the end of the rule of St. Basil and of the institutes of the fathers. St. Augustine, on the other hand, formed his rule to the example of the apostolic life, as is evident by comparing his rule to what is said and written of the apostolic life, so that he began to live under the rule constituted under the holy apostles. And in the same sermon (where the rule is found) he said as much: "For we want to live the apostolic life." Who then doubts that the apostolic way of life must be preferred to all other forms of life? Therefore, with what magnificence must the rule be extolled which has such an exemplar from which it is drawn!