Mencius - Book 2, Part 1, Chapter 3

Mencius said, 'He who, using force, makes a pretense to benevolence is the leader of the princes. A leader of the princes requires a large kingdom. He who, using virtue, practices benevolence is the sovereign of the kingdom. To become the sovereign of the kingdom, a prince need not wait for a large kingdom. T'ang did it with only seventy lî, and king Wan with only a hundred.

'When one by force subdues men, they do not submit to him in heart. They submit, because their strength is not adequate to resist. When one subdues men by virtue, in their hearts' core they are pleased, and sincerely submit, as was the case with the seventy disciples in their submission to Confucius. What is said in the Book of Poetry,

"From the west, from the east,
From the south, from the north,
There was not one who thought of refusing submission,"

is an illustration of this.'
~ James Legge translation via nothingistic.org ~

Go here to read the introductory post to this serialized version of the Works of Mencius.