Sagan was a critic of , having said of the ancient Greek philosopher: "Science and mathematics were to be removed from the hands of the merchants and the artisans. This tendency found its most effective advocate in a follower of named Plato" and "He (Plato) believed that . He advised the astronomers not to waste their time observing the stars and planets. It was better, he believed, just to think about them. Plato expressed hostility to observation and experiment. He taught contempt for the real world and disdain for the practical application of scientific knowledge. Plato's followers succeeded in extinguishing the light of science and experiment that had been kindled by and the ."
Sagan however was hopeful that the natural impact threat and the intrinsically double edged essence of the methods to prevent these threats, would serve as a "new and potent motivation to maturing international relations". Later acknowledging that, with sufficient international oversight, in the future a "work our way up" approach to fielding nuclear explosive deflection methods could be fielded, and when sufficient knowledge was gained, to use them to aid in . His interest in the use of nuclear detonations in space grew out of his work in 1958 for the 's , concerning the possibility of detonating a nuclear device on the Lunar surface.
From and his frequent appearances on , Sagan became associated with the "billions and billions". Sagan said that he never actually used the phrase in the series. The closest that he ever came was in the book , where he talked of "billions billions":