The history of mankind is one of continuous development from the realm of necessity to the realm of freedom. This process is never-ending. In any society in which classes exist class struggle will never end. In classless society the struggle between the new and the old and between truth and falsehood will never end. In the fields of the struggle for production and scientific experiment, mankind makes constant progress and nature undergoes constant change, they never remain at the same level. Therefore, man has constantly to sum up experience and go on discovering, inventing, creating and advancing. Ideas of stagnation, pessimism, inertia and complacency are all wrong. They are wrong because they agree neither with the historical facts of social development over the past million years, nor with the historical facts of nature so far known to us (i.e., nature as revealed in the history of celestial bodies, the earth, life, and other natural phenomena).

Quoted in "Premier Chou Enlai's Report on the Work of the Government to the First Session of the Third National People's Congress of the People's Republic of China " (December 21-22, 1964).

Natural science is one of man's weapons in his fight for freedom. For the purpose of attaining freedom in society, man must use social science to understand and change society and carry out social revolution. For the purpose of attaining freedom in the world of nature, man must use natural science to understand, conquer and change nature and thus attain freedom from nature.

Speech at the inaugural meeting of the Natural Science Research Society of the Border Region (February 5, 1940).

The Marxist philosophy of dialectical materialism has two outstanding characteristics. One is its class nature: it openly avows that dialectical materialism is in the service of the proletariat. The other is its practicality: it emphasizes the dependence of theory on practice, emphasizes that theory is based on practice and in turn serves practice.

"On Practice" (July 1937), Selected Works, Vol. I, p. 297.

Marxist philosophy holds that the most important problem does not lie in understanding the laws of the objective world and thus being able to explain it, but in applying the knowledge of these laws actively to change the world.

Ibid ., p. 304.

Where do correct ideas come from? Do they drop from the skies? No. Are they innate in the mind? No. They come from social practice, and from it alone; they come from three kinds of social practice, the struggle for production, the class struggle and scientific experiment.

Where Do Correct Ideas Come from? (May 1963), 1st pocket ed., p. 1.

It is man's social being that determines his thinking. Once the correct ideas characteristic of the advanced class are grasped by the masses, these ideas turn into a material force which changes society and changes the world.

Ibid .

In their social practice, men engage in various kinds of struggle and gain rich experience, both from their successes and from their failures. Countless phenomena of the objective external world are reflected in a man's brain through his five sense organs - the organs of sight, hearing, smell, taste and touch. At first, knowledge is perceptual. The leap to conceptual knowledge, i e., to ideas, occurs when sufficient perceptual knowledge is accumulated. This is one process in cognition. It is the first stage in the whole process of cognition, the stage leading from objective matter to subjective consciousness, from existence to ideas. Whether or not one's consciousness or ideas (including theories, policies, plans or measures) do correctly reflect the laws of the objective external world is not yet proved at this stage, in which it is not yet possible to ascertain whether they are correct or not. Then comes the second stage in the process of cognition, the stage leading from consciousness back to matter, from ideas back to existence, in which the knowledge gained in the hrst stage is applied in social practice to ascertain whether the theories, policies, plans or measures meet with the anticipated success. Generally speaking, those that succeed are correct and those that fail are incorrect, and this is especially true of man's struggle with nature. In social struggle, the forces representing the advanced class sometimes suffer defeat not because their ideas are incorrect but because, in the balance of forces engaged in struggle, they are not as powerful for the time being as the forces of reaction; they are therefore temporarily defeated, but they are bound to triumph sooner or later. Man's knowledge makes another leap through the test of practice. This leap is more important than the previous one. For it is this leap alone that can prove the correctness or incorrectness of the first leap in cognition, i.e., of the ideas, theories, policies, plans or measures formulated in the course of reflecting the objective external world. There is no other way of testing truth.

Ibid., pp. 1-3.*

Often, correct knowledge can be arrived at only after many repetitions of the process leading from matter to consciousness and then back to matter, that is, leading from practice to knowledge and then back to practice. Such is the Marxist theory of knowledge, the dialectical materialist theory of knowledge.

Ibid ., P. 3.*

Whoever wants to know a thing has no way of doing so except by coming into contact with it, that is, by living (practising) in its environment… If you want knowledge, you must take part in the practice of changing reality. If you want to know the taste of a pear, you must change the pear by eating it yourself… If you want to know the theory and methods of revolution, you must take part in revolution. All genuine knowledge originates in direct experience.

"On Practice" (July 1937), Selected Works, Vol. I, pp. 299-300.

Knowledge begins with practice, and theoretical knowledge which is acquired through practice must then return to practice. The active function of knowledge manifests itself not only in the active leap from perceptual to rational knowledge, but - and this is more important - it must manifest itself in the leap from rational knowledge to revolutionary practice.

Ibid ., p. 304.*

It is well known that when you do anything, unless you understand its actual circumstances, its nature and its relations to other things, you will not know the laws governing it, or know how to do it, or be able to do it well.

"Problems of Strategy in China 's Revolutionary War" (December 1936), Selected Works, Vol. I, p. 179.

If a man wants to succeed in his work, that is, to achieve the anticipated results, he must bring his ideas into correspondence with the laws of the objective external world; if they do not correspond, he will fail in his practice. After he fails, he draws his lessons, corrects his ideas to make them correspond to the laws of the external world, and can thus turn failure into success; this is what is meant by "failure is the mother of success" and "a fall into the pit, a gain in your wit".

"On Practice" (July 1937), Selected Works, Vol. I, pp. 296-97.

We are Marxists, and Marxism teaches that in our approach to a problem we should start from objective facts, not from abstract definitions, and that we should derive our guiding principles, policies and measures from an analysis of these facts.