Pluralist ideas can be traced back to early liberal *political philosophy, and notably to the ideas of John Locke (1632-1704) and C.L. Montesquieu (1689-1775). Their first systematic development, however, was in the contributions of James Madison (1751-1836) to the Federalist Papers (1787-89), in which he advocated a system of divided government based upon the *separation of powers, *bicameralism and *federalism in order to resist majoritarianism and to provide minority interests with a guaranteed political voice. The link between pluralism and *democracy has been emphasized by modern pluralist theorists such as Robert Dahl (1956). Political pluralism is widely regarded as the key feature of *liberal democracy, in that it both allows electors to express independent views and gives them a mechanism through which they can remove unpopular government. Nevertheless, pluralist thinkers generally emphasise that democracy in modern societies operates less through formal or electoral machinery and more through a constant interplay between government and organized groups or interests. In this sense pluralist democracy can be seen as an alternative to parliamentary democracy and to any form of majoritarianism. Pluralist ideas and values have in many ways been revived by the emergence of *postmodernism, which rejects all monolithic theories of society and extols the virtues of debate and *discourse.