There is one line in tonight's "Anne Murrow Lindbergh: A Conversation with Eric Sevaried" on Channel 9 from 8 to 9 p.m. that is both poetic and symbolic of this engrossing hour of conversation.

Charles A. Lindbergh's widow is talking about her husband's death and she tells Sevareid: "When a man dies, it's like a tree falling. And you see the whole length of him. It isn't foreshortened when you are looking up. You see all the different periods of his life."

And that is what Sevaried allows Anne Morrow Lindbergh to do, intruding only to carry her through the fascinating life and character of the man who was first authentic American hero of this century.

The interview is punctuated rather than interrupted from time to time by still photos and newsreel footage of his famous flight to Paris, their flights to the Orient, scenes from the trial of Bruno Richard Hauptmann, the alleged kidnapper and murderer of their son, their exile to Europe, his controversial trip to Berlin, his speeches against American involvement in World War II and his service, as a civilian, in the Air Corps during the war.

His statements in Germany about the Luftwaffe and his speeches on behalf of the American First Committee so enraged Franklin D. Roosevelt that he took away his commission in the Army Air Corps. But its commanding officer, Hap Arnold, got Lindbergh out to the Pacific as a civilian where he made 50 combat flights and shot down a a Japanese plane.

Anne Morrow Lindbergh claims in the interview that her husband was used by the Americans and the Germans. The American government wanted him to report back on the state of the Luftwaffe while the Germans wanted him to overstate the strength of their air power in an effort to intimidate Britain and France.

This action plus his opposition to the war and the anti-Semitic over-tones of that opposition, turned Lindbergh the hero into Lindbergh the hated. In a perfect line, his widow tells Savareid: "Hero worship and devil baiting are two parts of the same coin."

Sevareid is able to elicit such frankness because he knows how to ask a disturbing question with civility and grace. It's an old-fashioned technique of journalism called good manners.

By virtue of this technique, he allows this truly extraordinary woman to be frank about herself and about the man whom she loved all the years they were together and in the years since they have been apart.

She and Sevareid also allow those who were not yet born in the days when her husband was this nation's most-illustrous hero to understand why America loved him so much and how hurt and betrayed they felt when they no longer could continue that love and adoration.