In the letter of Damian Byrne to the Dominican Family on the subject of collaboration, he made a bold declaration by identifying the Order as fundamentally familial from the beginning: “The Dominican order was born a family.” Indeed, centuries of Dominican history and tradition indicate three distinct branches of First, Second, and Third Orders. However, though the idea of a family, which is made up of men and women, as well as of clerics and laity, can be construed as present from the beginning, the Tertiaries gained official status only years after the death of St. Dominic. This was through the Rule crafted by the sixth successor of the founder of the Order.
The Dominican diocesan priest lives a life consecrated to God not only by his baptism and ordination to the priesthood, but also by sharing in the spirit and mission of the Order of Preachers. He remains under the jurisdiction of his Ordinary, but takes up a new relationship with the Order and with his brother priests in the fraternity. He becomes a true member of the Dominican Family after he makes his solemn promise to live according to the Rule of the Priestly Fraternities of St. Dominic until death. He receives grace through his profession to live a life that is guided by the Dominican spirit of contemplation, disciplined by theological study and prayer, and combined with apostolic zeal to preach the Good News.