Luc de Clapiers, marquis de Vauvenargues (1715-1747) was a French moralist who, fittingly enough given this quotation, died young at the age of 31. An officer in the French military, Vauvenargues' health was destroyed during the Siege of Prague in 1742. Upon retiring from the army he built a friendship with Voltaire, a relationship that has perhaps more than anything bookmarked him in the annals of history. His only publication, a collection of essays and aphorisms published at Voltaire's recommendation, was released the year of his death and only gained a popular following 50 years later.
"In order to achieve great things, we must live as though we were never going to die."
Source: The Merriam-Webster Dictionary of Quotations (1992)