Once upon a time, a mother took her son to see the Supreme Court in session. The little boy sat patiently as lawyers presented their arguments, and the justices listened dispassionately. And then a fly landed on the forehead of one of the justices, who raised his hand to brush it off.

The little boy tugged at his mother’s sleeve. “Did you see that!” he said. “One of them’s alive!”

On many occasions, I have used this story as a stepping stone on a promising line of thought. To the boy, the distant solemnity of the Justices made their vitality a matter of doubt. Thus the story suggests a parallel recognition: though the people of the past are distant from us in time, they were as fully alive in their moment as we are in ours. Like us, they lived the edge of the moment, as surprised as we are by the twists and turns of the unfolding future.

Why does this matter?

Moving an audience in the direction of this recognition offers an effective recovery program from fatalism and resignation. When we recognize the full vitality of the people who preceded us on the planet, we are reminded of our own powers of choice, and we are encouraged to exercise those powers with vigor and hope.

And which individual has done the most to give this treatment program a chance to redeem us?

Here’s my own answer: documentary-filmmaker Ken Burns. ...