Philip Kintner, a retired history professor at Grinnell College, died on January 1, 2012. He arrived at the College after I had graduated, and I never got to know him. The College’s obituary for him contained some words of wisdom that I would like to share.
From his teachers at Wooster College and Yale University, he said he “learned the invaluable lesson that nothing written has but one meaning, and that intelligent people can disagree heatedly on interpretations without anyone being right or wrong, and no one being hurt.”
From his own teaching, he learned three essentials. “One, the amount of sheer effort — work — required to keep on top of one’s many subject areas [and] teach them meaningfully to students. … Two, that one never knows enough. … Three, that a certain amount of humility is essential. … A teacher should always allow students to think they can know as much or more as their instructor, IF they are willing to pursue the topic.”
 Grinnell College, In Memoriam–Philip L. Kintner, http://www.grinnell.edu/etal/inmemoriam/philip-kintner.