The doctrine that the King can do no wrong applies not only to legal offences, but also to political errors. The principle developed slowly, as a part of the long movement that has brought the royal authority under the control of public opinion; not that the process was altogether conscious, or the steps deliberately planned, but taking constitutional history as a whole, we can see that it tended to a result, and in speaking of this it is natural to use terms implying an intent which the actors did not really possess. To keep the Crown from actual violations of law was not always easy, but it was far more difficult to prevent it from using its undoubted prerogatives to carry out an unpopular policy. Parliament could do something in a fitful and intermittent way by refusing supplies or insisting upon the redress of particular grievances, but that alone was not enough to secure harmony between the Crown and the other political forces of the day. There could, in the nature of things, be no appropriate penalty for royal misgovernment. In the Middle Ages, indeed, a bad king or a weak king might lose his throne or even his life; but in more settled times such things could not take place without a violent convulsion of the whole realm,--a truth only too well illustrated by the events of the seventeenth century. An orderly government cannot be founded on the basis of personal rule tempered by revolution. Either the royal power must be exercised at the personal will of the monarch, or else other persons who can be made accountable must take part in his acts of state. [Sidenote: A Minister Responsible for Each of his Acts.]