"The Marxist-Leninist theory must not be regarded as a collection of dogmas, as a catechism, as a symbol of faith, and the Marxists themselves as pedants and dogmatists.

"Mastering the Marxist-Leninist theory does not at all mean learning all its formulas and conclusions by heart and clinging to their every letter. To master the Marxist-Leninist theory we must first of all learn to distinguish between its letter and substance.

"Mastering the Marxist-Leninist theory means assimilating the substance of this theory and learning to use it in the solution of the practical problems of the revolutionary movement under the varying conditions of the class struggle of the proletariat.

"Mastering the Marxist-Leninist theory means being able to enrich this theory with the new experience of the revolutionary movement, with new propositions and conclusions, it means being able to develop it and advance it without hesitating to replace — in accordance with the substance of the theory — such of its propositions and conclusions as have become antiquated by new ones corresponding to the new historical situation.

"The Marxist-Leninist theory is not a dogma but a guide to action."