There is an imperialism that deserves all honor and respect — an imperialism of service in the discharge of great duties. But with too many it is the sense of domination and aggrandisement, the glorification of power. The price of peace is eternal vigilance. These have often been attributed to Thomas Jefferson, but also to Thomas Paine, Abraham Lincoln, and many others; Lord Denning in The Road to Justice (1988) states that the phrase originated in a statement of Irish orator John Philpot Curran in 1790: "It is the common fate of the indolent to see their rights become a prey to the active. The condition upon which God hath given liberty to man is eternal vigilance."

As quoted in The Life Of Lord Courtney (1920) by G. P. Gooch