Democracy is a system of processing conflicts in which outcomes depend on what participants do, but no single force controls what occurs and its outcomes. The uncertainty of outcomes is inherent in democracy. Democracy makes all forces struggle repeatedly to realize their interests and devolves power from groups of people to sets of rules. Western democracy, as distinct from that which existed in pre-modern societies, is generally considered to have originated in city-states such as Classical Athens and the Roman Republic, where various schemes and degrees of enfranchisement of the free male population were observed before the form disappeared in the West at the beginning of late antiquity. The English word dates back to the 16th century, from the older Middle French and Middle Latin equivalents. According to American political scientist Larry Diamond, democracy consists of four key elements: a political system for choosing and replacing the government through free and fair elections; the active participation of the people, as citizens, in politics and civic life; protection of the human rights of all citizens; a rule of law, in which the laws and procedures apply equally to all citizens. Todd Landman, nevertheless, draws our attention to the fact that democracy and human rights are two different concepts and that "there must be greater specificity in the conceptualisation and operationalisation of democracy and human rights". The term appeared in the 5th century BC to denote the political systems then existing in Greek city-states, notably Athens, to mean "rule of the people", in contrast to aristocracy (ἀριστοκρατία, aristokratía), meaning "rule of an elite". While theoretically these definitions are in opposition, in practice the distinction has been blurred historically. The political system of Classical Athens, for example, granted democratic citizenship to free men and excluded slaves and women from political participation. In virtually all democratic governments throughout ancient and modern history, democratic citizenship consisted of an elite class, until full enfranchisement was won for all adult citizens in most modern democracies through the suffrage movements of the 19th and 20th centuries.