The only way to get good service is to give somebody power to render it, facing the fact that power which will enable a man to do a job well will also necessarily enable him to do it ill if he is the wrong kind of man.
 Theodore Roosevelt, Theodore Roosevelt; an Autobiography (1913). copy citation

Context

“It represented that device of old-school American political thought, the desire to establish checks and balances so elaborate that no man shall have power enough to do anything very bad. In practice this always means that no man has power enough to do anything good, and that what is bad is done anyhow.
In most positions the "division of powers" theory works unmitigated mischief. The only way to get good service is to give somebody power to render it, facing the fact that power which will enable a man to do a job well will also necessarily enable him to do it ill if he is the wrong kind of man. What is normally needed is the concentration in the hands of one man, or of a very small body of men, of ample power to enable him or them to do the work that is necessary; and then the devising of means to hold these men fully responsible for the exercise of that power by the people.” source