Engels pointed out in the preface to the third volume of Capital: "If a person wants to study scientific problems, he must first learn to read the works he wants to use as the author wrote them, and first of all not read what is not in the original work." "For the vast number of party members and cadres, it is inevitable that they will encounter some difficulties in the initial stage of reading the original works, but Marxism is a scientific truth that guides the working class to understand and transform the world. After the publication of the first volume of Capital, Marx said: "The analytical method I have used has not yet been used in economic problems, which makes the first chapters quite difficult to read." "This is a disadvantage, and I have no other way to do about it than to point it out in advance to the readers who seek the truth, and to warn them. There is no smooth road in science, and only those who are not afraid of hard work and climb along the steep mountain road can hope to reach the glorious summit. In order to get to the bottom of the question of the state, which is "one of the most complex and difficult to understand," Lenin advised university students to take the time to read "at least a few of the major works of Marx and Engels." He said: "At first, some people may be frightened by the difficulty of understanding, so I would like to remind you again not to be disappointed by this, and that what you did not understand when you read it the first time you read it will understand it the next time you read it, or when you study it from the other side in the future." He emphasized: "Anyone who wants to seriously investigate and comprehend it independently must study it again and again, discuss it repeatedly, and think from all sides in order to gain a clear and thorough understanding." Comrade Mao Zedong emphasized that a scientific attitude is an attitude of seeking truth from facts and having a definite purpose, and that "without a scientific attitude, that is, without the unity of Marxist-Leninist theory and practice, it is called no party spirit, or it is called incomplete party spirit." These study methods are also applicable to our study of Marxist classics today.

-- "Leading Cadres Should Pay Attention to the Study of Marxist Classics -- Speech at the Opening Ceremony of the Second Batch of Advanced Classes in the Spring Semester of 2011 of the Central Party School" (May 13, 2011)

Further reading:

Marx, Lenin, Mao Zedong and other revolutionary teachers have made tremendous efforts in the pursuit of truth.

Marx spent many years reading and writing at his desk, and his rest was to walk back and forth indoors, so that he stepped on the carpet between the door and the window, like a path through the grass. In order to write the twenty-odd pages of English labour law in Capital, he studied the entire library of the Blue Books containing the reports of the British and Scottish Commissions of Inquiry and the Factory Inspectors.

Lenin also continued to read and write while in prison. In order not to be discovered by the guards, he poured milk into the bread and secretly used the milk as ink to write, and when it dried, he could not see it at all. When the guard opened the door and came in, he ate the small "inkwell" in one gulp. He once wrote in a letter, "I ate six 'inkwells' today". Volume 40 of Lenin's Collected Works, compiled by the Marxist-Leninist Institute of the Central Committee of the CPSU, has 500 pages, of which 400 pages are Lenin's comments, marginal notes and excerpts from the works of Marx and Engels.

Mao Zedong repeatedly studied Das Kapital, and the People's Publishing House also printed a large-character edition of Das Kapital for him. He read "The History of the United Communist Party" and Li Da's "Outline of Sociology" more than ten times. He has repeatedly read "The Communist Manifesto", "Capital", "Lenin's Selected Works", "Critique of the Gotha Program", "State and Revolution", etc., and many chapters and paragraphs have been annotated and outlined. Every time he reads a book or an article, he draws various symbols such as circles, bars, and dots in important places, and writes many comments on the header and blank spaces. At the time of his death, he had a large-print bound copy of the Communist Manifesto and two copies of the Communist Manifesto published during the war years.

At the opening ceremony of the second batch of advanced courses in the spring semester of 2011 of the Central Party School, Xi Jinping elaborated on the expositions of Marx, Lenin, Mao Zedong and other revolutionary mentors on "reading the original works", and explained how to overcome difficulties in understanding when reading the original works. Just as he emphasized, "Leading cadres, especially senior cadres, should regard the systematic mastery of the basic theories of Marxism as their ability to take care of their own affairs, and study Marxism-Leninism, Mao Zedong Thought, especially Deng Xiaoping Theory, the important thinking of the 'three represents,' and the scientific outlook on development in an honest and original manner." ”