Full Idea
Since all cannot, in a community exceeding a single small town, participate personally in any but some very minor portions of the public business, it follows that the ideal type of a perfect government must be representative.
Gist of Idea
People can only participate in decisions in small communities, so representatives are needed
Source
John Stuart Mill (Representative Government [1861], p.217-8), quoted by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 4 'Representative'
Book Reference
Wolff,Jonathan: 'An Introduction to Political Philosophy (Rev)' [OUP 2006], p.93
A Reaction
Wolff offers Mill as the principal spokesman for representative democracy. It is not only the difficulty of achieving participation, but also the slowness of decision-making. Modern technology may be changing all of this.