GEORGE B KISTIAKOWSKY, the Lawrence Professor of Chemistry Emeritus who died last week at 82, never had any doubts about the apocalyptic potential of nuclear weapons. weapons that he played a key role in designing at the U.S. Government's Los Alamos laboratory during World War II.

"I'm sure," the explosives expert told the New York Times after witnessing the first atomic test on July 16, 1945, "that at the end of the world--in the last millisecond of the earth's existence--the last human will see what we saw."

This first-hand view of the atom's destructive power--and his own role in unleashing that power--deepened Kistiakowsky's sense of the imperative need for peace in the nuclear age. "After working so long on those weapons," he said many years later, "I came to the conclusion that the time had come to control them." As a science advisor to Presidents Eisenhower, Kennedy, and Johnson, Kistiakowsky earned a reputation within the highest circles of government as one of disarmament's most eloquent and distinguished spokesmen.

But when the U.S. took a more bellicose position in the arms race and in Vietnam, the Russian-born physical chemist grew increasingly skeptical of the political elite's commitment to peaceful policies. He left the Johnson Administration in 1967, devoting his efforts to building a "mass political movement for peace." The Council for a Live able World, an arms control organization that he chaired from 1977 until 1982, became a leading force in educating both the public and the Congress about the threat of nuclear war.

In the years just before his death--although he often expressed pessimism about his own efficacy--Kistiakowsky began to see his efforts bear fruit as a full-scale peace movement blossomed on both sides of the Atlantic. In the United States, this movement can already claim major victories. A 10-state nuclear freeze referendum won overwhelming approval in the November elections, and--largely in response to that expression of public sentiment--the House recently rejected President Reagan's dangerous and costly plans to build a nuclear-tipped MX missile.

Despite its important recent progress, however, Kistiakowsky recognized that the struggle to bring the arms race under control still has a long way to go. No matter how many gains it makes, he told The Crimson last June, "the movement must never rest on its laurels...It must keep the [politicians'] feet in the fire." And, repeating this urgent message recently in a "parting" editorial in the Bulletin of Atomic Scientists, Kistiakowsky warned: "Forget the [official] channels...Concentrate instead on organizing."

In issuing these warnings, Kistiakowsky expressed not only his fears about the future, but, more importantly, his abiding faith in the wisdom and decency of ordinary people. Even though Kistiakowsky is gone, citizens still can confirm his faith by carrying on the unfinished business of the peace movement. In so doing, they will build an enduring monument to Kistiakowsky himself--a brilliant scientist and a courageous human being whose inspiring deeds stand as testimony to the power possessed by every dedicated and principled individual.