At Harvard, the tutors formed the primary teaching staff during the seventeenth and eighteenth centuries. Most historians, however, have dismissed the colonial tutors as a group of transient instructors with little commitment to teaching and date the rise of professional faculty to the 1750s. Colonial Harvard had two types of teachers. Professors, first appearing in the 1720s, taught in specific disciplines and lived off-campus. Tutors, active in the college since the 1640s, were responsible for teaching the entire basic curriculum, lived in the college, and supervised the students' curricular and extracurricular activities. Historians of higher education studying the rise of the academic profession have used a more narrow view of the professional idea. In the 1690s, the Harvard tutors had assumed primary control for Harvard, and had successfully changed the intellectual climate, opening the door for more liberal theology and more progressive thought.