The Separation of PowersThe idea of separating powers among the various branches of government to avoid the tyranny of concentrated power falls under the larger category of checks and balances. But The Federalist Papers see another virtue in the separation of powers, namely, an increase in governmental efficiency and effectiveness. By being limited to specialized functions, the different branches of government develop both an expertise and a sense of pride in their roles, which would not be the case if they were joined together or overlapped to any considerable degree.
Qualities that might be crucial to one function could be ill-suited for another. Thus Hamilton termed "energy in the executive" as essential to defend the country against foreign attacks, administer the laws fairly, and protect property and individual liberty, which he viewed as closely related rights. On the other hand, not energy but "deliberation and wisdom" are the best qualifications for a legislator, who must earn the confidence of the people and conciliate their divergent interests. This difference of needs also explains why executive authority should be placed in the hands of one person, the president, since a plurality of executives could lead to paralysis and "frustrate the most important measures of government, in the most critical emergencies of the state." That is, once the legislature, reflecting the will of the people, has rendered its deliberate and fully debated judgment by passing a law, the executive must firmly carry out that law without favoritism, resisting any self-interested pleas for exception. And in the event of an attack by a foreign state, the executive must have the power and energy to respond immediately and forcefully. As for the judiciary, the qualities wanted there are special as well: not the executive's energy and dispatch, nor the legislator's responsiveness to popular sentiment or his ability to compromise, but "integrity and moderation" and, by being appointed for life, freedom from popular, executive or legislative pressures.