“Within its narrow classrooms the college must see to it that she [the student] is taught with breadth of view, and not only in so-called safe subjects, but in so-called dangerous subjects, in economics and history and psychology and religion; taught with sincerity which will call out sincerity in her; with imagination which will create for her a true and breathing picture of the world she is to meet; and with liberty of spirit which will make her all through her life demand ceaselessly for herself and others the same quickening air.”