The pure idea of democracy, according to its definition, is the government of the whole people by the whole people, equally represented. Democracy, as commonly conceived and hitherto practiced, is the government of the whole people by a mere majority of the people exclusively represented.
 John Stuart Mill, Considerations on Representative Government (1861). copy citation

Context

“A completely equal democracy, in a nation in which a single class composes the numerical majority, can not be divested of certain evils; but those evils are greatly aggravated by the fact that the democracies which at present exist are not equal, but systematically unequal in favor of the predominant class. Two very different ideas are usually confounded under the name democracy. The pure idea of democracy, according to its definition, is the government of the whole people by the whole people, equally represented. Democracy, as commonly conceived and hitherto practiced, is the government of the whole people by a mere majority of the people exclusively represented. The former is synonymous with the equality of all citizens; the latter, strangely confounded with it, is a government of privilege in favor of the numerical majority, who alone possess practically any voice in the state.” source