 What has been called another version of the branch theory was propounded in the wake of the Second Vatican Council by some Roman Catholic theologians, such as Robert F. Taft Michael A. Fahey, and others.In this theory, the Eastern Orthodox Church and the Roman Catholic Church are two "sister churches".This theory was rejected outright by the Catholic Church, which applies the term "sister Churches" only to the relations between particular Churches, such as the sees of Constantinople and Rome.Most Eastern Orthodox theologians also reject it.