“If it is only difficult, it is done; if it is impossible, we shall see.”
Si cela n'est que difficile, c'est fait; si cela est impossible, nous verrons.
Response to Marie Antoinette when she informed him that something she needed done might be difficult.
Quoted by François Guizot in Biographie Universelle, Volume 6 http://books.google.com/books?id=za4FAAAAQAAJ&q=%22n'est+que+difficile+c'est+fait+si+cela+est+impossible+nous+verrons%22&pg=PA567#v=onepage (1812)