Unify theory and practice. That's a core theme of the book.

Marxism-Leninism is the interests of the working class. "Marxism-Leninism is the science of proletarian revolution... It can be thoroughly understood and mastered only by those who... have made the ideals of the proletariat their own"

"The science of Marxism-Leninism is of little of no use to anyone who is not a genuine revolutionary, who is not a proletarian revolutionary to the core, who does not want to bring about socialism and communism throughout the world and emancipate all mankind, to anyone who does not want revolution or is unwilling to carry it through to the end and wants to stop half-way."

Party members from the working class sometimes grasp this more intuitively than well-read non-working-class people. "For example, the section in Capital concerning surplus value is difficult for some Party members, but not for those from the working class. The reason is that in the process of production and of struggle against the capitalists, the workers come to know all too well how the capitalists calculate wages and working hours, exploit the workers for profit and oppress them."

Having said that, even people from the working class have to "study Marxist-Leninist theory modestly and diligently" and "we should add that no Party member can maintain a proletarian stand and express a proletarian ideology concretely in every revolutionary struggle unless he studies the theory and method of Marxism-Leninism diligently and guides his thinking and action accordingly."

Prior prejudices and selfish interests block people from becoming a person with proletarian/Marxist motivations. Some root them out and some don't. "When they handle practical problems in the course of revolutionary struggle, the habits and prejudices which they have brought with them from the old society and their individualistic calculations led them to think in terms of personal gain or loss"

Fighting bravely is not enough. The right class background is not enough. Ideological study is also necessary. You need firmness, but also the ideology-guided wisdom to know what to do.

Being familiar with theory, and being firmly pro-prole, you will be able to answer questions such "as the question of whom to rely upon, whom to unite with and whom to overthrow, the question of who are our direct allies, who is the main enemy and who are the secondary enemies, the question of rallying all possible allies, including even secondary enemies under certain conditions, to defeat the main enemy, and the question of making timely changes in strategy and tactics to meet changing situations".

Take the current situation of the Russo-Ukrainian war – the left is confused about who to support and who to oppose.

"national united front against Japan" – A United Front is a concept the person reading this should learn and understand. It means a temporary alliance for limited aims for definite action. It actually means united with people you don't agree with on certain things. For example, communists might unite with SocDems on some environmental thing. It's the opposite of squabbling and cancelling, what Liu Shaoqi calls "'closed-doorism' and sectarianism". The fact that it's a limited alliance for limited aims is what he's talking about when he says "certain comrades went to the other extreme, maintaining that since the Kuomintang had joined in the resistance to Japan, there was hardly any distinction between it and the Communist Party". He calls the cancel-culture refusal to unite with anyone a left (ultra-left) mistake, and the overfriendliness ("appeasement and capitulation") a right mistake.

"certain comrades did not understand that the contradiction between the Chinese nation and Japanese imperialism had become the principal one while the contradictions among the different classes and political groups within the country had become secondary." – that's interesting. It's saying that you unite with whoever is with you on the main issue of the hour.

"The proletariat cannot just emancipate itself alone; it must fight for the emancipation of all the working people, the emancipation of the nation and of all mankind, for only thus can it fully emancipate itself."

"The proletariat must rid the whole of human society of exploitation, oppression and class struggle once and for all, for only thus can it genuinely and finally emancipate itself. Hence a firm proletarian stand must be sharply differentiated from ‘closed-doorism’ and sectarianism. In waging struggles the proletariat and its political party must establish close ties with the masses of working people, form revolutionary alliances with other revolutionary classes and parties and lead the working masses and all their allies forward together; they must represent the interests of more than 90% of the population of the country."

Make clear delineations between the proletarian-communists and all other groups, even when you form a united front with them.

"In every stage of the development of the revolutionary struggle they must combine the interests of the part with the interests of the whole and immediate interests with long-term interests."

Lenin quote from 'What Is To Be Done?' that class consciousness means seeing the issues of the day in as manifestations of bourgeois or proletarian interests

Lenin: “The Social-Democrat's ideal should not be a trade-union secretary, but a tribune of the people, able to react to every manifestation of tyranny and oppression, no matter where it takes place, no matter what stratum of class of people it affects; he must be able to generalize all these manifestations to produce a single picture of police violence and capitalist exploitation” – this is a great quote, he even drags the pigs. The political form of communism is the dictatorship of the proletariat by direct means.

Thought is necessary as well as experience. He quotes Mao 'On Practice' about this.

"If only we study this theory, apply it and master it in close conjunction with revolutionary practice, we shall be able to understand the inner connections of the changes taking place all around us and to know how and in what direction the various classes are now moving and will soon move, and we shall be able to determine our line of action and have confidence in the future of the revolutionary movement."

Lenin's statement, "Without revolutionary theory there can be no revolutionary movement."

Marxism emphasises the importance of theory