The office of worldwide leader is not in the Brethren's founding theory, which had no offices at all, and its emergence is the central historical fact about the Exclusive line in the twentieth century. James Taylor Senior, a New York linen merchant, was the recognised leading brother from the 1920s until 1953; his son James Taylor Junior succeeded to that position in 1959 and drove the tightening of separation through the 1960s; after the 1970 crisis the leadership passed through James Symington and John S. Hales to John's son Bruce D. Hales, a Sydney businessman, in 2002. The titles used inside the fellowship — the Man of God, the Elect Vessel, the Minister of the Lord in the Recovery — are not constitutional offices, and the body maintains that the leader exercises spiritual ministry rather than authority. His ministry is transcribed and circulated and read in meetings worldwide, and former members and outside researchers describe the practical authority as effectively unlimited.