Under a calm aspect, which arises from the absolute control he has over his mind, his brilliant imagination and ambitious aspirations often carry him away; but the circumspection which he imposes on himself, and the satisfactory reflection of his fame, restrain him and lead him to doubts, which, perhaps, constitute his sole defect." Mirabeau predicted to the Duke of Brunswick, from this moment, leading influence in the affairs of Germany after the death of the king of Prussia, whom Germany called the Great King.
The duke was then fifty years of age.

He defended himself, in his conversations with Mirabeau, from the charge of loving war.

"Battles are games of chance," said he to the French traveller: "up to this time I have been fortunate.

Who knows if to-day, although more lucky, I should be as well used by fortune ?" A year after this remark he made the triumphant invasion of Holland, at the head of the troops of England.
Some years later Germany nominated him generalissimo.
But war with France, however it might be grateful to his ambition as a soldier, was repugnant to his mind as a philosopher.

He felt he should but ill carry out the ideas in which he had been educated.