This episode's headline: Feeling Down; Brave New World; Conversation. ANCHOR: JIM LEHRER; GUESTS: DORIS KEARNS GOODWIN; MICHAEL BESCHLOSS;HAYNES JOHNSON; RICHARD NORTON SMITH; ROGER WILKINS; ANNE NIVAT;CORRESPONDENTS: KWAME HOLMAN; RAY SUAREZ; SPENCER MICHELS; MARGARET WARNER; GWEN IFILL; TERENCE SMITH; KWAME HOLMAN