51 was one of twenty-six articles written by James Madison from 1787 to 1788 in order to persuade the people of New York to ratify the Constitution. To him, conflicts of interests are inborn in human nature and as a result, people fall into various groups. He wanted to make sure that one group does not command all the decisions of the general public. The central issue for Madison was how to minimize the risk of tyranny of a minority (dictatorship) as well as tyranny of the majority (over minorities).
The need for government proves that men abuse power, for "if men were angels, no government would be necessary." The best way to ascertain that power does not gradually compile in any one branch is to present constitutional safeguards that would make such concentration hard. The constitutional rights of everyone should check one man's personal interests and ambitions. Since no one is perfect, the rulers and the ruled, there has to be methods for the government to control the people and to control itself. The government's dependence on the will of the people is one way to control itself, but there has to be other ways as well. .
The "separation of powers" between the legislative, executive, and judicial branches is one solution that the Constitution provides. Dividing power helps to check its growth in any one direction, but power cannot be divided into perfectly equal portions. In the republican form of government, the legislative branch has a tendency to be the most powerful. That is why the framers divided it into two houses, the House of Representatives and the Senate, and gave different methods of election for each house. .
The system of checks and balances also makes sure that none of the branches abuse their powers. This gives multiple means to offset the power that any one branch of the government might otherwise have over another. For example, the president can veto (reject) any bills that Congress want to pass.