Forrest McDonald reviews Joseph Ellis’ His Excellency: George Washington and likes it. A sample:

Restraining himself so as to earn the approval of the wise and the just was, as Ellis makes abundantly clear, no easy task for Washington. Citing Gouverneur Morris’s memorial eulogy, Ellis points out that ’’Washington’s legendary calmness and statuelike stolidity masked truly volcanic energies and emotions.’’ Morris described him as a man of ’’tumultuous passions’’ and said that ’’his wrath was terrible.’’ In Morris’s view, and in Ellis’s, Washington’s ’’vaunted capacity for self-control derived from the virulence of the internal demons he had been required to master.’’

The other internal quality derived from the 18th-century concept of character. As Ellis indicates, people of the time thought that ’’character was not just who you were but also what others thought you were.’’ Public figures and denizens of polite society customarily took on a character, like a part in a play, and attempted to wear it at all times. If a person persisted with the character long enough and consistently enough, it became second nature. Benjamin Franklin played a bewildering variety of characters that obscured which if any was the real one. Thomas Jefferson played a number of public characters, but was never comfortable with any. Washington took on a progression of characters, each nobler and more exalted than the last, until he had transformed himself into something more than human.

Addition: I just found this review of Ellison’s book by David Hackett Fischer. It is much more critical than is McDonald’s:
"The thesis of this book is that Washington’s life was a continuing struggle against dark inner forces, which led to an "obsession with control," which in turn caused him to favor control mechanisms for America, including a highly disciplined regular army, strong central government, and hierarchical society.

Psychological interpretations of this sort are difficult to test, but one can ask if they fit external evidence and enlarge our understanding. Some elements of Ellis’s conflict model are solidly confirmed by other sources. Jefferson wrote of Washington, "his temper was naturally high toned, but reflection and resolution had obtained a firm and habitual ascendancy. If however, it broke its bounds, he was most tremendous in his wrath." Adams added, "He had great self-command. It cost him great exertion sometimes, and a constant constraint." Many historians have noticed Washington’s striking resemblance to his favorite model, Joseph Addison’s Cato, who "while good, and just, and anxious for his friends," was "still severely bent against himself."

That evidence supports part of Ellis’s thesis, but as his argument unfolded, this reader found himself arguing back.