"Without destruction, there can be no construction."

"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."

"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."

"We must learn to look at problems from all sides, seeing not only the front but also the back, not only the positive but also the negative."

"We should support whatever the enemy opposes and oppose whatever the enemy supports."