The teacher's role is to transmit laboriously acquired assets to students and to open intellectual doors hitherto closed. The student's role is to pay attention, benefit from superior knowledge and experience, study diligently, and participate fruitfully when the moment is ripe. This role is not static, for the goal of authoritative instruction is to bring students to a point of independence and mastery from which they can proceed on their own. Assuming that the professor and student do what is expected of them, the student will grow in confidence and be able to "interact" at progressively higher levels of readiness. The thoughtful lecture, moderated by a judicious use of dialectic, is a powerful instrument for intellectual liberation.

Those eager for students to control their own learning might bear in mind that self-instructed minds are a rare breed. Self-instruction is possible, but only with exceptional motivation and self-discipline, qualities notably lacking in a generation of students raised on heavy diets of bad schooling, shallow entertainment, and effortless gratification. Seldom does one encounter a Lewis Mumford, who never graduated from college but took scholarship and authorship by storm, or a Srinivasa Ramanujan, whose mastery of number theory sprang from the blue and mystified leading mathematicians.

While professors are surely able to learn from students from time to time, a professor who enters a classroom of tyros and says, "Let us learn from one another" is afflicted with role confusion. Students may be full of themselves for an instant, but are likely to find in the context of subject matter how little of consequence they have to exchange. Collaboration implies there is something, rather than just someone, with which to collaborate -- including accurate, relevant knowledge, a critical mindset, preliminary study, and personal discipline. Previously uninstructed students are not likely to have those assets in usable abundance.

Hostility toward lecturing is part of a recent general assault on most forms of legitimate authority. Authoritative instruction requires hierarchy, and in these egalitarian times, hierarchy is a dirty word. But all good teaching and learning must accept a hierarchical frame of reference. Arithmetic must come before calculus. Basic facts about the Reformation must come before analysis of its causes. Drawing 101 must precede Drawing 102. Writing intelligible English sentences must come before writing a novel like Ulysses. Greek verb forms must be mastered before Plato can be translated.

We cannot grasp everything at once. The full light of knowledge is perceived in stages. Aside from geniuses who spring full-blown into the world (a Bernini, a Mozart, a Gauss), most of us are obliged by reality to climb toward understanding one rung at a time, with occasional skips for the very bright and clever. Learning is hierarchical even if imparted dialectically, for all subjects are better entered at the beginning than at the end. Teachers resistant to that simple truth about teaching and learning will flounder and will confuse their students. The value of a good lecturer is to know where to begin, what to include and leave out, and by what stages to lead a student to mastery of a subject.