Who is Dr. Quartz from The Four Loves and what is their importance?

Dr. Quartz is a teacher who. He is a beloved instructor, who inspires his students, most of whom, maintain contact after their lessons are complete. Quartz entertains his former students in his home, sharing evenings of conversations. The problem is that sooner or later the students have ideas of their own and question (or oppose) Dr. Quartz. He doesn't realize that he's done his job well and that they are thinking for themselves, but is instead hurt that they would disagree with his interpretations. He therefore immediately banishes them from his life.