"If there is no struggle, there is no progress. Those who profess to favor freedom, and yet depreciate agitation, are men who want crops without plowing up the ground. They want rain without thunder and lightning. They want the ocean without the awful roar of its many waters. This struggle may be a moral one; or it may be a physical one; or it may be both moral and physical; but it must be a struggle. Power concedes nothing without a demand. It never did and it never will. Find out just what a people will submit to, and you have found out the exact amount of injustice and wrong which will be imposed upon them; and these will continue till they are resisted with either words or blows, or with both. The limits of tyrants are prescribed by the endurance of those whom they oppress. Men may not get all they pay for in this world; but they must pay for all they get. If we ever get free from all the oppressions and wrongs heaped upon us, we must pay for their removal. We must do this by labor, by suffering, by sacrifice, and, if needs be, by our lives, and the lives of others."
Frederick Douglass, “An address on West India Emancipation”, August 4, 1857
(I came across this quote today at http://louisproyect.wordpress.com/ in this post.)