Unless man has the wit and the grit to build his civilization on something better than material power, it is surely idle to talk of plans for a stable peace.
The moving finger writes; and having writ Moves on: not all your piety nor wit Shall lure it back to cancel half a line, Nor all your tears wash out a word of it.
Edward Fitzgerald (1809 - 1883)
Source: The Rubáiyát of Omar Khayyám, Persian writer & astronomer (c.1050–c.1123)
In most of mankind, gratitude is merely a secret hope of further favours. Note: A saying ascribed to Sir Robert Walpole by Hazlitt in his Wit and Humor: "The gratitude of place-expectants is a lively sense of future favours" is obviously derived from La Rochefoucauld.
Duc de La Rochefoucauld (1613 - 1680)
Source: Réflexions ou Sentences et Maximes Morales