Separated brethren is a term sometimes used by the Catholic Church and its clergy and members to refer to baptized members of other Christian traditions. The phrase is a translation of the Latin phrase fratres seiuncti. It is largely used as a polite euphemism in contexts where the terms "formal heretics" or "material heretics" might cause offense.
Since the Council of Trent, which formally condemned Protestant doctrines as heretical, the Catholic Church officially deems Protestants as material or formal "heretics" and has always taught that "outside the Church there is no salvation". However, Biblical passages like Romans 2:12-16 point to the importance of conscience in Catholic soteriology, which the Roman Catholic Church states it has always recognized. In c. 1960 – c. 1962 preparation work for draft texts of Second Vatican Council documents, a "report urged respectful use of the terms dissidents or separated brethren, in place of heretics and schismatics." After the Second Vatican Council, however, "that habit of unthinkingly hurling accusations of heresy at Protestants pretty much died out" in some contexts to avoid offense. Since at least the mid-1990s, the term has often been replaced by Catholic officials with phrases such as "other Christians".
A similar move to avoid causing offense occurred with some other religious groups as well. During a period of lessening tensions with Jewish groups, Pope John Paul II once referred to Jews as "elder brothers in the faith of Abraham", prior to a 1987 visit to the United States.