Publius begins by telling the reader that we discussed some of the issues raised by the doctrine known as "separation of powers." This principle of republican government does not imply that the three branches need to be completely separate and independent. The very opposite is true. In order that this doctrine can operate effectively, each branch of government must have sufficient power to impose some restraints over the other two.
The Constitution grants to each branch certain exclusive powers. These powers should not be interfered with; however, power not carefully controlled tends to expand. Our first task, he writes, is to understand and distinguish the differences between legislative, executive, and judicial power. This is necessary to protect the legitimate powers of each branch.
It is not enough to simply set forth on paper what the proper boundaries are. There must be some latitude, some overlap, in the definition of powers assigned to each branch. Experience with state governments has shown that theoretical checks written into the state constitutions are inadequate, particularly in preventing the growth of legislative power. The most serious mistake made by the framers of republican forms of government is that they concerned themselves exclusively with the problem of too much executive power. They forgot that legislative tyranny is as evil as executive tyranny.
In hereditary monarchies the king is feared; in direct democracies the executive is also feared because the legislative branch is too large to effectively check the executive, and power is so highly diffused that conflicts are difficult to resolve. In direct democracies, the legislature cannot tyrannize because it cannot govern.
In the proposed government, however, it is the legislative branch that is most likely to abuse power. More power, both unrefined and unlimited, has been granted to it than to the other two branches. In addition, the legislative branch controls the money and has the greatest influence in the determination of salaries paid to government employees. Such a situation invites corruption. Presidential power, on the other hand, is simpler in nature, and the Constitution clearly defines and limits it. The same is true of judicial power. Any attempt by these two branches to infringe upon the Congress would be quickly detected and blocked.
The idea of separation of powers was, of course, not new, nor novel to the founding fathers. Plato and Polybius were concerned with it in their discussion of a mixed state, and the concept of a tempered or mixed monarchy was a familiar one during the Middle Ages. In England, the struggle between the crown and the courts of common law, and between the crown and Parliament, had given concrete importance to the separation of powers. Harrington had considered it a prerequisite for free government, and Locke had given it a subsidiary role in his theory of parliamentary supremacy. However, the idea of mixed government had never had a definite meaning. It had connoted a balancing of social and economic interests, or a sharing of power by such corporations as communes or municipalities. Often, the concept was proposed as a remedy against extreme centralization and as a reminder that a political organization would only work if there existed some degree of comity and fair dealing between its various parts. It was Montesquieu who modified the ancient doctrines by making the separation of powers into a system of legal checks and balances between the parts of a constitution.
Montesquieu's idea, which was derived inductively from a study of the English constitution, gained a great deal of popularity in America. After having been hailed by the colonists in their attempts to curb the powers and prerogatives of the royal governor, the principle of the separation of powers was a guiding light for the constitution making that took place after independence had been declared. It was mentioned in the Virginia Declaration of Rights in 1776 and in the preamble of the constitution of Massachusetts of 1780, and it thus found official recognition in America years before it was put down in the famous article 16 of the French Declaration of the Rights of Man and Citizen. The members of the Philadelphia Convention reaffirmed the validity of the Montesquieuian concept, the more so since the preceding years had shown a lapse in its strict observance, which was due largely to the belief that a strong legislature, considered by many as the great liberator from monarchical despotism, could not very well be destructive of the Frenchman's ideal of liberty.
The Federalist accepts the framers' version of the separation of powers. Aware of the probability of legislative usurpations, the authors of that work desire a separation that would be likely to eliminate legislative supremacy. No matter how much Hamilton and Madison might disagree on certain aspects of the separation of powers, they see eye to eye with respect to that major point. Montesquieu's influence on the Papers, however, goes still further. Not only is his idea of a separation of the executive, legislative, and judicial branches accepted, but also his concept of checks and balances. Montesqieu seems to have had a special fascination of the authors, especially for Madison. This popularity may have been due partly to Montesquieu's inductive method, which was likely to have a certain appeal to statesmen who were, in a way, suspicious of mere philosophical speculations. However, what probably accounts most for Hamilton's, Madison's, and Jay's sympathy for the Frenchman was the fact that he chose the English constitution as an example of the merits of a separation of powers. Montesquieu thus became the great foreign herald of the rights of Englishmen. These were the rights that our authors believed in, that they hoped would exist in the free government under the Constitution.