François de Callières, sieur de Rochelay et de Gigny (14 May 1645, Thorigny-sur-Vire, Lower Normandy – 5 March 1717, Paris) was a member of the Académie française, a diplomat and writer, a special envoy of Louis XIV who was one of three French plenipotentiaries who signed the Peace of Ryswick in 1697; his De la manière de négocier avec les souverains, 1716 ("On the manner of negotiating with sovereigns", translated as The Practice of Diplomacy), based on his experiences in negotiating the Treaty and having its origins in a letter to the Regent, Philippe, duc d'Orléans, to whom the work was dedicated, became a textbook for eighteenth-century diplomacy: Thomas Jefferson had a copy in his library at Monticello. Of this book John Kenneth Galbraith declared "One wonders why anything more needed to be said on the subject." The companion volume, on the other hand, De la science du monde et des connaissances utiles à la conduite de la vie is less known, though it was quickly translated into English and was admired by Jefferson and Harold Nicolson. Source: Wikipedia (en)