Why did Frederick William III appoint Karl vom Stein as chief minister of Prussia in 1807?

Following the catastrophic defeat of Prussia by Napoleon I and the subsequent Treaty of Tilsit in 1807, Frederick William III was forced to dismiss his minister Karl von Hardenberg at Napoleon's behest.1

Under these dire circumstances, the King invited Karl, Reichsfreiherr vom und zum Stein to serve as chief minister, acting specifically on the recommendation of Napoleon. By this time, the Prussian state was in a state of collapse, and even the King recognized that the old system was discredited and that the nation required urgent, fundamental reforms to be placed on a more modern footing. Stein’s appointment was further facilitated by the fact that some liberally inclined members of the bureaucracy were prepared to collaborate with him to implement these necessary changes.12