I’ve had, for example, over 75 years of looking not at the preacher up in the pulpit, but at the congregation under assault. When the cleric is employed in what we call preaching, I note an interesting phenomenon among the listeners. They employ a reflex called the nictitating membrane (also called a plica semilunaris or third eyelid), something usually found in reptiles, birds, fish, and a few mammals. It’s a translucent eye cover: Woodpeckers activate it just before their bills strike the tree trunk, to protect their eyes from damaging vibration; polar bears avoid snow-blindness with the extra layer; camels and sea lions use theirs as a defense against sand. Human beings are not thought to have anything but a vestigial remnant of it. But look around at any congregation as the dominie warms to his task, and you’ll see it almost universally deployed. On the other hand, when the preacher is telling a story, every eye, from infant to doddering, is fixed upon him.

The best lecturers are steeped in their topic and attuned to their audiences. The late John Kemeny, former president of Dartmouth and chairman of the commission investigating the 1979 accident at the Three Mile Island nuclear power plant in Pennsylvania, gave a lengthy report to the Dartmouth community on a Parents’ Weekend. He spoke cogently, without notes, held his audience rapt right to the end, and explained the near-calamity in terms any of us could understand.

The best preachers use stories and metaphors to engage, inform, and inspire. The famous 19th-century evangelist Dwight Moody had an incomparable gift for both. His fundamentalist views were a long way from mine, but his sermons are fascinating for their stories. I once had a book of them that he had personally annotated in stubby pencil; to my everlasting regret, I sold it. He used humor, too – a feature sadly missing from most sermons. He was holding a revival meeting once at Oxford University. A young Anglican medical student stopped at the auditorium door to listen briefly. An English don droned through an interminable prayer. “Suddenly,” the student recalled years later, “a rotund, bearded man in an American suit and vest popped up from behind the speaker and shouted, “While Brother Witherspoon says his prayer, let’s sing a hymn. Take it away, Brother Sankey...” As the congregation burst into song, the student’s life was changed. He later became Sir Wilfred Grenfell, founder of the famous Labrador medical missions.

The best professors and teachers give us more than facts and dates; they give us the back stories, personal tales, and oftentimes even the dirt. When Professor Shewmaker gets done telling the saga of the machinations and sub rosa deals that got the Panama Canal property transferred from French to United States ownership and out from under the guns of the Colombian navy; and then how Congress, acting at lightning speed, recognized Panama as a sovereign nation, you can imagine Teddy Roosevelt’s elbows bruised from nudging and his eyelids worn out by winking. No wonder there were always more students than room in Ken’s courses.

The most perilous public speaking involves slide projectors. Unless the audience is keenly interested in the topic, the effect is toxic. Sometimes the projector doesn’t work. Often, lecturers on Arctic canoe trips, for example, slip into a long series of flower close-ups – dwarf fireweed, arnica, cotton grass, lupine. After half a dozen or so rapturous exudations from the audience, its enthusiasm gives out, for fear that, encouraged, the lecturer will show a few hundred more. It was while watching one of those poisonous shows that I resolved that, should I ever get a chance to do it, I would petition for a law to make audience abuse a misdemeanor, and after a second conviction, a felony. In our society – with the exception of NRA- or Tea Party-dominated “town hall meetings” – it’s considered poor form to boo or hiss or throw overripe vegetables toward the stage. Instead, we suffer quietly to the end. Surely we deserve tort remedies from this sort of mistreatment.

Mark Twain, quite possibly the funniest and most-quoted lecturer we’ve ever produced, did almost nothing but tell stories. Self-deprecating, hyperbolic, and irreverent, he did not suffer fools gladly. I dip into the first volume of his autobiography late each evening as unconsciousness creeps up on me. Last night, however, I couldn’t help laughing out loud.

Twain was describing the meetings of the Monday Night Club, a bunch of clergymen, businessmen, and prominent Connecticut pooh-bahs who got together every second Monday evening all through the winter to discuss chosen topics. The topic the week he describes was “Dreams.” An essayist spoke for 20 minutes, followed by the other members present, who each spoke for ten minutes. Supper, cigars, and conversation followed, often till about midnight. Just the thought of a group of middle-aged men soberly discussing dreams evokes images of elephants waltzing. Twain, who was as carefully attuned to the sensitivities of audiences as any speaker ever, savages the club members: “If (Joe Twichell) talked...it was easily perceptible that he had something to say. But almost as a rule, he gave his ten minutes to the next man – and whenever he gave it to Charles E. Perkins, he ran the risk of getting lynched on his way home by the rest of the membership. Charles E. Perkins was the dullest white man in Connecticut – and he probably remains that to this day; I have not heard of any real competitor.” I think I’ll name my new law after Mister Clemens. All I lack are some influential cosponsors.