 The conservative "historic" movement holds to certain traditional positions that have been challenged since the 1950s.By contrast, progressive Adventists typically question some of the church's distinctive teachings, and some of the fundamental beliefs of the church that are held by mainstream Adventists.In a 1985 survey of North American Adventist lecturers, 45% described themselves as liberal compared to other church members, 40% as mainstream, 11% as conservative, and 4% gave no response to the question.