The Marxist philosophy of dialectical materialism has two outstanding characteristics. One is its class nature: it openly avows that dialectical mate… - Mao Zedong

What should our policy be towards non-Marxist ideas? As far as unmistakable counter-revolutionaries and saboteurs of the socialist cause are concerned, the matter is easy, we simply deprive them of their freedom of speech. But incorrect ideas among the people are quite a different matter. Will it do to ban such ideas and deny them any opportunity for expression? Certainly not. It is not only futile but very harmful to use crude methods in dealing with ideological questions among the people, with questions about man's mental world. You may ban the expression of wrong ideas, but the ideas will still be there. On the other hand, if correct ideas are pampered in hothouses and never exposed to the elements and immunized against disease, they will not win out against erroneous ones. Therefore, it is only by employing the method of discussion, criticism and reasoning that we can really foster correct ideas and overcome wrong ones, and that we can really settle issues.

The Chinese people consider weddings as red happy events and funerals white happy events. I find them very rational. The Chinese know dialectics. Weddings will produce children. A child is split out of the body of the mother. It is a sudden change, a happy event. One individual is split into two or three, or even 10, like the aircraft carrier.
The common people find the deaths, changes and occurrences of new matters happy events. When a person dies, a memorial meeting is held. While the bereaved weep in mourning, they feel it is also a happy event. Actually, it is. Just imagine if Confucius were still living and here at this meeting in Huai-jen Hall, he would be over 2,000 years old and it wouldn’t be so good! If one subscribes to dialectics and yet disapproves of death, it will be metaphysics. Disasters are social phenomena, natural phenomena. Sudden changes are the most fundamental law of the universe. Birth is a sudden change; so is death. In the several decades from birth to death, it is a gradual change. If Chiang Kai-shek should die, we would clap our hands in joy. If Dulles should die, none of us would shed a tear. This is because the death of matters of the old society is a good thing, hoped for by everyone. While the birth of new things is good, their death is naturally not good. The failure of Russia’s 1905 revolution and the loss of our base in the South were equivalent to the seedlings destroyed by hailstorm and downpour. It is naturally not good. And the problem of replacing the destroyed seedlings arises.

Discover the truth through practice, and again through practice verify and develop the truth. Start from perceptual knowledge and actively develop it into rational knowledge; then start from rational knowledge and actively guide revolutionary practice to change both the subjective and the objective world. Practice, knowledge, again practice, and again knowledge. This form repeats itself in endless cycles, and with each cycle the content of practice and knowledge rises to a higher level. Such is the whole of the dialectical-materialist theory of knowledge, and such is the dialectical-materialist theory of the unity of knowing and doing.