"Before the cares of the White House were his own, President Harding is reported to have said that government, after all, is a very simple thing."

"He must have said that, if he said it, as a fleeting inhabitant of fairyland. The opposite is the truth. A constitutional democracy like ours is perhaps the most difficult of man's social arrangements to manage successfully. Our scheme of society is more dependent than any other form of government on knowledge and wisdom and self-discipline for the achievement of its aims. For our democracy implies the reign of reason on the most extensive scale. The Founders of this Nation were not imbued with the modern cynicism that the only thing that history teaches is that it teaches nothing. They acted on the conviction that the experience of man sheds a good deal of light on his nature. It sheds a good deal of light not merely on the need for effective power if a society is to be at once cohesive and civilized, but also on the need for limitations on the power of governors over the governed. To that end, they rested the structure of our central government on the system of checks and balances. For them, the doctrine of separation of powers was not mere theory; it was a felt necessity. Not so long ago, it was fashionable to find our system of checks and balances obstructive to effective government. It was easy to ridicule that system as outmoded — too easy.... A scheme of government like ours no doubt at times feels the lack of power to act with complete, all-embracing, swiftly moving authority.... I know no more impressive words on this subject than those of Mr. Justice Brandeis: 'The doctrine of the separation of powers was adopted by the Convention of 1787 not to promote efficiency, but to preclude the exercise of arbitrary power. The purpose was not to avoid friction, but,  by means of the inevitable friction incident to the distribution of the governmental powers among three departments, to save the people from autocracy.'"

Wrote Justice Felix Frankfurter in 1952, concurring in Youngstown Sheet & Tube Co. v. Sawyer.