Sagan intended this as an allusion to Thomas Carlyle. 'A sad spectacle!' exclaimed Thomas Carlyle, contemplating the possibility that millions of planets circle other suns. 'If they be inhabited, what a scope for pain and folly; and if they be not inhabited, what a waste of space!' Contact is not the only place this allusion occurs in Sagan, who previously quoted Carlyle during a conference on extraterrestrials; Google makes a video of the conference available online.