There is no such thing as an achieved liberty; like electricity, there can be no substantial storage and it must be generated as it is enjoyed, or the lights go out.

Robert H. Jackson (1892-1954) US Supreme Court Justice (1941-54), lawyer, jurist, politician

“The Task of Maintaining Our Liberties: The Role of the Judiciary,” speech, Boston (24 Aug 1953)
    (Source)

Dinner address at the American Bar Association Diamond Jubilee dinner. Reprinted in the American Bar Association Journal (Nov 1953) [citation 39 A.B.A. J. 961 (1953)].