"We must learn to do economic work from all who know how. No matter who they are, we must respect them as teachers, learn from them respectfully and conscientiously."

"The highest criterion for judging the truth is practice."

"Correct ideas come from social practice, and from it alone; they come from three kinds of social practice, the struggle for production, the class struggle and scientific experiment."

"There are two kinds of peace: one is the peace of slavery, and the other is the peace of freedom."

"Investigation may be likened to the long months of pregnancy, and solving a problem to the day of birth. To investigate a problem is, indeed, to solve it."