Separation of Powers
The separation of powers is normally understood as a constitutional doctrine according to which political freedom is best guaranteed by separating the powers of government into legislative, executive, and judicial branches, each with its own jurisdiction. The purpose of this arrangement is to ensure that no single group or individual can control all the levers of power and, thereby, rule despotically. The legislature has primary responsibility for lawmaking, while the impartial interpretation of the law and the application of it to particular cases falls under the purview of the judiciary. The executive must obey the rules established by the legislature and enforced by the judiciary.
Charles-Louis de Secondat, baron de Montesquieu (1689–1755), provided the separation of powers with its canonical statement in The Spirit of the Laws (1752), but early intimations of the idea can be found in ancient Greece and Rome, where the systematic study of constitutions first began. Aristotle was the first comparative political thinker to notice that all constitutions have deliberative, judicial, and executive elements. Although he did not argue that government should be organized into separate branches, he believed that different types of constitutions (democratic, aristocratic, or monarchic) should be “mixed,” so as to counteract the tendencies to corruption inherent in all pure constitutions. Greek historian Polybius (c. 200–c. 118 BCE) used this theory to explain Roman history, as did Renaissance Florentine thinker Niccolò Machiavelli. The immediate precursor to the development of the separation of powers, however, was seventeenth-century English political thought, particularly the work of John Locke.
The separation of powers is an inherently conservative doctrine, in that it was intended to prevent the use of state power to promote radical social change, and yet it contributed to the rise of constitutional democracy. It offered a constitutional design that promised simultaneously to check monarchical abuses of power and limit the growing ambitions of legislators. It appealed to the nobility, who felt squeezed between overweening absolutist monarchs and pressures to expand popular participation. Although the separation of powers is not a theory of democratic government—it can be, and was, adopted by constitutional monarchies—it gave impetus to the spread of democracy by offering a way of reconciling the will of the people with the rule of law. As such, the doctrine was celebrated in the Declaration of the Rights of Man and the Citizen (1789) during the French Revolution, and it was the subject of intense debate by the framers of the Constitution of the United States.
Over the course of the nineteenth century the doctrine lost relevance, and its meaning was gradually restricted to a more specific distinction among types of democratic constitutions—specifically, presidential versus parliamentary government. Critics of Montesquieu charged that he had misread the English constitution, by Page 449 | Top of Articlefailing to appreciate how in Westminster parliamentary systems the legislature and executive were fused in the cabinet and in the office of the prime minister. Such a fusion of powers made parliamentary systems elective dictatorships, or so claimed the critics. The Constitution of the United States, with its separate election of president and congress, came to be seen as the closest approximation of the separation of powers.
Montesquieu’s critics misunderstood the separation of powers, however. They imagined a watertight separation of branches of government in which no person or group could be a member of more than one branch at a time and no branch could encroach upon the powers of another. This view, which is more of a caricature than a description of any observed political system, had no expositors: No major constitutional theorist ever called for such an absolute separation. James Madison (1751–1836) was the first to reject this caricature, not only because it misrepresented Montesquieu, but, more importantly, because the partial encroachment of branches of government was necessary as a check against the abuse of power: Ambition should counteract ambition; checks and balances, rather than watertight separation of branches of government, would limit tendencies toward abuse of power. Madison was firmly of the same mind as Montesquieu in his conviction that only power can check power.
In the twentieth century the idea of the separation of powers continued to occupy a respected place in legal scholarship and jurisprudence, but lost appeal among social and political theorists. The development of the administrative functions of the state, especially with the expansion of the welfare state, placed more public-sector activity outside the sphere of legislation and into the hands of specialized agencies and experts. The rise of totalitarianism by electoral means in Italy and Germany suggested that the separation of powers was a feeble bulwark against modern antidemocratic and illiberal movements. Political freedom depended more on the degree of social and economic equality, the competitiveness of political-party systems, and a culture of constitutionalism, than on the constitutional separation of powers. Above all, as political science became a more scientific discipline, the language of the separation of powers seemed outdated and formalistic. A new view of institutions arose, building on economic and organizational theory, in which the separation of powers was understood to mean the separate election of executive and legislature in a presidential system of government.
The Anglo-American tendency to treat the separation of powers as a virtual synonym of presidentialism has been resisted by continental political theorists, especially in recent work on deliberative democracy. German philosopher Jürgen Habermas argued that the various branches of government in constitutional democracies correspond to different logics of argumentation, and their separation is necessitated by these discourses. The legislature is the chief deliberative body, yet it has little administrative power. The weakness of the legislature as an administrative body ensures that its deliberations are insulated from the temptations inherent in the exercise of such power and hence oriented toward the production of general laws for the public good.
The purpose of the separation of powers, according to Habermas, is to bind the exercise of administrative power to the deliberative power of citizens acting in concert. The executive administers policies consistent with parliamentary law; it represents the need for action within the rule of law. Equally important is the separation of power between legislature and judiciary. The role of the judiciary is to impartially enforce the law, and court procedures reflect this imperative. The fact that judges can deny citizens their most basic liberties requires that the rules and procedures for doing so be established not by the judges themselves but by the legislature as a body that represents the collective, deliberative power of the whole community. Critics of deliberative democracy object to its highly abstract and normative tone, while exponents see it as a promising beginning for a renewed discussion of the separation of powers.
Habermas, Jürgen. 1996. Faktizität und Geltung: Beiträge zur Diskurstheorie des Rechts und des demokratischen Rechsstaats [Between Facts and Norms: Contributions to a Discourse Theory of Law and Democracy]. Trans. William Rehg. Cambridge, MA: MIT Press.
Hamilton, Alexander, James Madison, and John Jay. [1787–1788] 1982. The Federalist Papers. New York: Bantam Books.
Montesquieu, Charles-Louis de Secondat, baron de.  1949. De l’esprit des lois [The Spirit of the Laws]. Trans. Thomas Nugent, with introduction by Franz Neumann. New York: Hafner Publishing.
Vile, M. J. C. 1998. Constitutionalism and the Separation of Powers. 2nd ed. Indianapolis, IN: Liberty Fund.
Maxwell A. Cameron