Mencius - Book 6, Part 2, Chapter 6A

Shun-yü K'wan said, 'He who makes fame and meritorious services his first objects, acts with a regard to others. He who makes them only secondary objects, acts with a regard to himself. You, master, were ranked among the three chief ministers of the State, but before your fame and services had reached either to the prince or the people, you have left your place. Is this indeed the way of the benevolent?'

Mencius replied, 'There was Po'î; he abode in an inferior situation, and would not, with his virtue, serve a degenerate prince. There was Î Yin; he five times went to T'ang, and five times went to Chieh. There was Hûi of Liû-hsiâ; he did not disdain to serve a vile prince, nor did he decline a small office. The courses pursued by those three worthies were different, but their aim was one. And what was their one aim? We must answer "To be perfectly virtuous." And so it is simply after this that superior men strive. Why must they all pursue the same course?'

~ James Legge translation via nothingistic.org ~

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