I tried first the method of reason: I compared the danger of nuclear weapons with the danger of the Black Death. Everybody said, 'How true,' and did nothing. I tried alerting a particular group, but though this had a limited success, it had little effect on the general public or Governments. I next tried the popular appeal of marches of large numbers. Everybody said, 'These marchers are a nuisance'..
But whether mankind will think itself worth preserving remains a doubtful question.
Source:The Autobiography of Bertrand Russell, v.3:1944-1969, chap.4: The Foundation
More info.:http://russell-j.com/beginner/AB34-010.HTM