A civilized people have far other means of imparting civilization to those under their influence
 John Stuart Mill, Considerations on Representative Government (1861). copy citation

Context

“Hence even personal slavery, by giving a commencement to industrial life, and enforcing it as the exclusive occupation of the most numerous portion of the community, may accelerate the transition to a better freedom than that of fighting and rapine. It is almost needless to say that this excuse for slavery is only available in a very early state of society. A civilized people have far other means of imparting civilization to those under their influence; and slavery is, in all its details, so repugnant to that government of law, which is the foundation of all modern life, and so corrupting to the master-class when they have once come under civilized influences, that its adoption under any circumstances whatever in modern society is a relapse into worse than barbarism.” source