Marxism has always stressed the absolute necessity of the Party’s close links with the masses.This was stressed by Marx and Engels and one of the essential features of the Leninist party. Thus the History of the CPSU (B) concludes by drawing a historic lesson of the utmost need for close connections with the masses:

"Lastly, the history of the Party teaches us that unless it has wide connections with the masses, unless it constantly strengthens these connections, unless it knows how to hearken to the voice of the masses and understand their urgent needs, unless it is prepared not only to teach the masses but to learn from the masses, a party of the working class cannot be a real mass party capable of leading the working class millions and all the labouring people.

"A party is invincible if it is able, as Lenin says, ‘to link itself with, to keep in close touch with, and to a certain extent if you like, to merge with the broadest masses of the toilers, primarily with the proletariat, but also with the non-proletarian toiling masses.’ (Lenin, Collected Works, Russ, ed., Vol. XXV, p. 174.)

"A party perishes if it shuts itself up in its narrow party shell, if it severs itself from the masses, if it allows itself to be covered with bureaucratic rust.

"‘We must take it as the rule,’ Comrade Stalin says, ‘that as long as the Bolsheviks maintain connection with the broad masses of the people they will be invincible. And, on the contrary, as soon as the Bolsheviks sever themselves from the masses and lose their connection with them, as soon as they become covered with bureaucratic rust, they will lose all their strength and become a mere cipher....

"‘I think that the Bolsheviks remind us of the hero of Greek mythology, Antaeus. They, like Antaeus, are strong because they maintain connection with their mother, the masses, who gave birth to them, suckled them and reared them. And as long as they maintain connection with their mother, with the people, they have every chance of remaining invincible.

"‘That is the clue to the invincibility of Bolshevik leadership.’ (J. Stalin, Defects in Party Work.)"

Mao, starting from these basic standpoints, developed the concept of mass-line to a qualitatively new level. At the philosophical level he showed how it was an essential aspect of the Marxist theory of knowledge. At the political and organisational levels, he showed how it was the correct political line and also how it was the essential organisational line of inner-party relations.

"In all the practical work of our Party, all correct leadership is necessarily ‘from the masses, to the masses’. This means: take the ideas of the masses (scattered and unsystematic ideas) and concentrate them (through study turn them into concentrated and systematic ideas), then go to the masses and propagate and explain these ideas until the masses embrace them as their own, hold fast to them and translate them into action, and test the correctness of these ideas in such action. Then once again concentrate ideas from the masses and once again go to the masses so that the ideas are persevered and carried through. And so on, over and over again in an endless spiral, with the ideas becoming more correct, more vital and richer each time. Such is the Marxist theory of knowledge."

The 1945 CPC Resolution on Certain Questions in the History of Our Party, explains:

"As Comrade Mao Tse-tung says, the correct line should be ‘from the masses, to the masses’. To ensure that the line really comes from the masses and particular that it really goes back to the masses, there must be close ties not only between the Party and the masses outside the Party (between the class and the people), but above all between the Party’s leading bodies and the masses within the Party (between the cadres and the rank and the file); in other words there must be a correct organisational line. Therefore, just as in each period of the Party’s history Comrade Mao Tse-tung has laid down a political line representing the interests of the masses, so he has laid down an organisational line serving the political line and maintaining ties with the masses both inside and outside the Party."

"The concept of a correct relationship between the leading group and the masses in an organisation or in a struggle, the concept that correct ideas on the part of the leadership can only be ‘from the masses, to the masses’, and the concept that the general call must be combined with particular guidance when the leadership’s ideas are being put into practice — these concepts must be propagated everywhere — in order to correct the mistaken viewpoints among our cadres on these questions. Many comrades do not see the importance of, or are not good at, drawing together the activists to form a nucleus of leadership, and they do not see the importance of, or are not good at, linking this nucleus of leadership closely with the masses, and so their leadership become bureaucratic and divorced from the masses. Many comrades do not see the importance of, or are not good at, summing up the experience of mass struggles, but fancying themselves clever, are fond of voicing their subjectivist ideas, and so their ideas become empty and impractical. Many comrades rest content with making a general call with regard to a task and do not see the importance of, or are not good at, following it up immediately with a particular and concrete guidance, and so their call remais on their lips, or on paper or in the conference room, and their leadership become bureaucratic. .....we must correct these defects and learn to use the methods of combining the leadership with the particular in our study, in the check-up on work and in the examination of cadres’ histories; and we must also apply these methods in all our future work.

"Take the ideas of the masses and concentrate them, then go to the masses, persevere in the ideas and carry them through, so as to form correct ideas of leadership — such is the basic method of leadership."

Briefly, this is the essence of Mao’s mass-line.