In political science, the term polyarchy ( "many", arkhe "rule") was used by Robert A. Dahl to describe a form of government in which power is invested in multiple people. It takes the form of neither a dictatorship nor a democracy. This form of government was first implemented in the United States and France and gradually adopted by other countries. Polyarchy is different from democracy, according to Dahl, because the fundamental democratic principle is "the continuing responsiveness of the government to the preferences of its citizens, considered as political equals" with unimpaired opportunities. A polyarchy is a state that has certain procedures that are necessary conditions for following the democratic principle. In semblance, the word "polycracy" describes the same form of government, although from a slightly different premise: a polycracy is a state ruled by more than one person, as opposed to a monocracy. The word derives from Greek poly ("many") and kratos ("rule" or "strength"). Definitions Dahl's original theory of polyarchal democracy is in his 1956 book A Preface to Democratic Theory. His theory evolved over the decades, and the description in later writings is somewhat different. Dahl argues that "democracy" is an ideal type that no country has ever achieved. For Dahl, democracy is a system that is "completely responsive to all its citizens", and the closest to the democratic ideal any country can come is polyarchy. A Preface to Democratic Theory In the book, Dahl gives eight conditions that measure the extent to which majority rule is in effect in an organization. These are (p. 84): Every member of the organization performs the acts we assume to constitute an expression of preference among the scheduled alternatives, e.g., voting. In tabulating these expressions (votes), the weight assigned to each individual is identical. The alternative with the greatest number of votes is declared the winning choice. Any member who perceives a set of alternatives, at least one of which he regards as preferable to any of the alternatives presently scheduled, can insert his preferred alternative(s) among those scheduled for voting. All individuals possess identical information about the alternatives. Alternatives (leaders or policies) with the greatest number of votes displace any alternatives (leaders or policies) with fewer votes. The orders of elected officials are executed. Either all interelection decisions are subordinate or executory to those arrived at during the election stage, i.e., elections are in a sense controlling; or new