It is not necessary to succeed in order to persevere. As long as there is a margin of hope, however narrow, we have no choice but to base all our actions on that margin. America and Russia have one interest in common which may override all their other interests: to be able to live with the bomb without getting into an all-out war that neither of them wants.

As quoted in "Some Szilardisms on War, Fame, Peace", LIFE magazine, Vol. 51, no. 9 (1 September 1961), p. 79