This episode's headline: Killing A Weapon; Who May Teach?; Unnatural Nature. The guests include In Washington: GEORGE WILSON, The Washington Post; In New York: SAUL COOPERMAN, Commissioner of Education,; New Jersey; GARY CLABAUGH, Professor of Education; LaSalle University; JAMIE JAMES, Discover Magazine; In Denver: WOLFGANG BAYER, Nature Photographer. Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JIM LEHRER, Associate Editor