Mencius - Book 4, Part 2, Chapter 16

Mencius said, 'Never has he who would by his excellence subdue men been able to subdue them. Let a prince seek by his excellence to nourish men, and he will be able to subdue the whole kingdom. It is impossible that any one should become ruler of the people to whom they have not yielded the subjection of the heart.'
~ James Legge translation via nothingistic.org ~

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