Tis not in mortals to command success, but we’ll do more, Sempronius, we’ll deserve it.

From 1776 by David McCulough. Page 47.

Second only to his passion for architecture and landscape design was a love of the theater, which again was quite characteristic of Virginians. He had seen his first known theatrical production at age nineteen on a trip with his older brother to Barbados. It was the first and only time Washington had ever been beyond American shores and the place where he was “strongly attacked” by smallpox. Later, at Williamsburg, as a member of the Virginia legislature, he had attended the theater regularly. During a visit to Annapolis, he recorded going to “the play” four nights out of five. In New York later he attended the theater seven times and saw his first production of Hamlet.

But of all the theatrical productions he had seen it was Cato, by the English author Joseph Addison, the most popular play of the time, that Washington loved best. One line in particular he was to think of or quote frequently in his role now as commander-in-chief: “’Tis not in mortals to command success, but we’ll do more, Sempronius, we’ll deserve it.”

I really need to read that Cato play sometime.  I keep coming across references to its contemporary influence in histories of the Revolution.