Conscientious practice of self-criticism is still another hallmark distinguishing our Party from all other political parties. As we say, dust will accumulate if a room is not cleaned regularly, our faces will get dirty if they are not washed regularly. Our comrades' minds and our Party's work may also collect dust, and also need sweeping and washing. The proverb "Running water is never stale and door-hinge is never worm-eaten" means that constant motion prevents the inroads of germs and other organisms. To check up regularly on our work and in the process develop a democratic style of work, to fear neither criticism nor self-criticism, and to apply such good popular Chinese maxims as "Say all you know and say it without reserve", "Blame not the speaker but be warned by his words" and "Correct mistakes if you have committed them and guard against them if you have not" – this is the only effective way to prevent all kinds of political duct and germs from contaminating the minds of our comrades and the body of our Party.
"On coalition Government" (April 24, 1945), Selected Works, Vol. III, pp, 316-17.