Canada's leading man of letters, Robertson Davies, has some advice for American doctors: Resist science, trust wisdom, learn to laugh, read Rabelais and take yourselves less seriously.

"Do not let anything, even your work, eat you up and silence your common sense," Davies told a physician-filled audience of nearly 1,000 at the Johns Hopkins Medical Center last week during a symposium on theater and medicine.

The 71-year-old actor, dramatist, critic, teacher and author of 32 books -- including the celebrated "Deptford Trilogy" -- had been invited to address the topic "Can a Doctor Be a Humanist?" But he said a better title would be "How can a doctor possibly be a humanist in a society that increasingly tempts him to be a scientist?"

"It is easy -- it is tempting -- to choose the god of science," Davies said. "It is a powerful god indeed, but it is something of a trickster.

"Science may cure disease, but can it confer health?"

Medicine has changed since Davies was a young boy in Canada and, whatever the ailment, the family doctor prescribed a potion tasting "something like rusty nails and boiled rhubarb."

Today, Davies regards his doctor as "a middle man between me and a large pill works. He's lost his magic. Of course, I take the pills -- I am frightened not to do so -- but the reverence is gone."

But no matter how hard doctors strive for an image of personable, trustworthy professionalism, Davies said, "To the wretch sitting in your consulting rooms, you look like a god."

Davies urged physicians to ponder the implications of their own 5,000-year-old emblem: the caduceus, the winged staff of Mercury with the twin warring serpents spiraling around it.

The two snakes of the caduceus, he said, represent Knowledge and Wisdom, a kind of right and left side of medicine's intelligence. Unless the two forces are reconciled and kept in balance, the staff becomes lopsided.

That's exactly what Davies thinks has happened to modern medicine: The knowledge snake is overwhelming the wisdom snake, tilting medicine toward technology, dehumanized care and science's "pursuit of the new, the latest."

Knowledge is the mass of scientific facts and evidence doctors acquire during their education, Davies said. Wisdom is the inner humanistic voice that binds healer and patient.

"Knowledge can help you memorize 'Gray's Anatomy' and Osler's 'Principles and Practice of Medicine,' " he said. "But only wisdom can teach you what to do with what you have learned."

Acknowledging that he is prone to generalizing from personal experiences that scientists deem merely anecdotal, Davies said, "Well, it's your own fault. You should not ask novelists to talk to you if you want statistical analysis."

Fifty years ago, while a student at Oxford, Davies consulted a doctor for relief of a miserable cold and learned "a great lesson." Instead of writing out a prescription, the doctor persisted in asking all sorts of questions, as if Davies were to diagnose his own illness.

Finally, the doctor offered his diagnosis: Davies was taking his work too seriously, letting his studies and his writing eat him up. He needed to set aside time for other interests.

"You know, climbing mountains makes me a better doctor," the physician, an accomplished climber, told his patient.

One of the great virtues of Dr. William Osler, a pioneering teacher at Johns Hopkins Medical School, was that he "took neither himself nor his vast medical knowledge with total unremitting solemnity," Davies said.

Echoing one doctor's suggestion to his students on how to approach a new patient, Davies advised: "Don't just do something, stand there. In other words, hold science in check and let wisdom have its chance."

And what is the scourge of modern civilization? Not cancer, Davies said. Not smoking. Not nuclear war, but something far more pernicious.

"It is, quite simply, stupidity," he said, adding that stupidity is "particularly evil" when it disguises itself as "thought" and travels under the name "public opinion."

"Unquestionably, you have observed this evil among your patients," Davies said. "But have you ever mentioned it? Have you ever prescribed for it?"

Having diagnosed society's worst affliction, Davies offered his prescription. First, doctors must inoculate themselves against stupidity by "massive daily applications" of music, art and literature. For example, they should read Rabelais and Mark Twain, go to Marx Brothers films, learn to listen to others and laugh at themselves.

"Then," he said, "you must do the most difficult thing of all: You must be wholly honest with your patients."

What should a stupidity-fighting doctor say, for example, to a women who has taken up jogging and lost 20 pounds but complains that she still feels fat? Davies counsels candor:

"It is true that you jog in the flesh, but are you jogging in the spirit?" the doctor must say. "It is true that you are no longer fat in the flesh, but you are still fat-headed.

"Now, go read Rabelais and 'The Decline and Fall of the Roman Empire.' "