… is from Frederick Douglass’s August 3, 1857, speech delivered at Canandaigua, New York :
Find out just what any people will quietly submit to and you have found out the exact measure 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.
DBx: According to most accounts, the great classical-liberal Frederick Douglass  was born 200 years ago today in Cordova, Maryland.
Here’s Damon Root’s 2012 review of Nicholas Buccola’s The Political Thought of Frederick Douglass .