It is necessary to master Marxist theory and apply it, master it for the sole purpose of applying it. If you can apply the Marxist-Leninist viewpoint in elucidating one or two practical problems, you should be commended and credited with some achievement.
Mao ZedongOur enemies are all those in league with imperialism - the warlords, the bureaucrats, the comprador class, the big Landlord class and the reactionary section of the intelligentsia attached to them. The leading force in our revolution is the industrial proletariat. Our closest friends are the entire semi-proletariat and petty bourgeoisie. As for the vacillating middle bourgeoisie, their right wing may become our enemy and their left wing may become our friend - but we must be constantly on our guard and not let them create confusion within our ranks.
Mao ZedongThe People's Liberation Army is always a fighting force. Even after countrywide victory, our army will remain a fighting force during the historical period in which classes have not been abolished in our country and the imperialist system still exists in the world. On this point, there should be no misunderstanding or wavering.
Mao Zedong