John Stuart Mill

Aim at something great; aim at things which are difficult; and there is no great thing which is not difficult. Do not pare down your undertaking to what you can hope to see successful in the next few years, or in the years of your own life. Fear not the reproach of Quixotism and impracticability, or to be pointed at as the knight-errants of an idea. After you have well weighed what you undertake, if you see your way clearly, and are convinced that you are right, go forward, even though you […] do it at the risk of being torn to pieces by the very men through whose changed hearts your purpose will one day be accomplished. Fight on with all your strength against whatever odds, and with however small a band of supporters. If you are right, the time will come when that small band will swell into a multitude: you will at least lay the foundations of something memorable, and you may […]—though you ought not to need or expect so great a reward—be spared to see that work completed which, when you began it, you only hoped it might be given to you to help forward a few stages on its way.

John Stuart Mill, ‘William Lloyd Garrison’, in The Collected Works of John Stuart Mill, Toronto, 1988, vol. 28, p. 202