无论在全人口中间，或者在知识分子中间，马克思主义者仍然是少数。因此，马克思主义仍然必须在斗争中发展。马克思主义必须在斗争中才能发展，不但过去是这样，现在是这样，将来也必然还是这样。正确的东西总是在同错误的东西作斗争的过程中发展起来的。真的、善的、美的东西总是在同假的、恶的、丑的东西相比较而存在，相… - Mao Zedong

Communism is at once a complete system of proletarian ideology and a new social system. It is different from any other ideology or social system, and is the most complete, progressive, revolutionary and rational system in human history. The ideological and social system of feudalism has a place only in the museum of history. The ideological and social system of capitalism has also become a museum piece in one part of the world (in the Soviet Union), while in other countries it resembles "a dying person who is sinking fast, like the sun setting beyond the western hills", and will soon be relegated to the museum. The communist ideological and social system alone is full of youth and vitality, sweeping the world with the momentum of an avalanche and the force of a thunderbolt. The introduction of scientific communism into China has opened new vistas for people and has changed the face of the Chinese revolution. Without communism to guide it, China's democratic revolution cannot possibly succeed, let alone move on to the next stage. This is the reason why the bourgeois die-hards are so loudly demanding that communism be "folded up". But it must not be "folded up", for once communism is "folded up", China will be doomed. The whole world today depends on communism for its salvation, and China is no exception.

Today, the danger of a world war and the threats to China come mainly from the warmongers in the United States. They have occupied our Taiwan and the Taiwan Straits and are contemplating an atomic war. We have two principles: first, we don’t want war; second, we will strike back resolutely if anyone invades us. This is what we teach the members of the Communist Party and the whole nation. The Chinese people are not to be cowed by U.S. atomic blackmail. Our country has a population of 600 million and an area of 9,600,000 square kilometres. The United States cannot annihilate the Chinese nation with its small stack of atom bombs. Even if the U.S. atom bombs were so powerful that, when dropped on China, they would make a hole right through the earth, or even blow it up, that would hardly mean anything to the universe as a whole, though it might be a major event for the solar system.

积极防御，又叫攻势防御，又叫决战防御。消极防御，又叫专守防御，又叫单纯防御。消极防御实际上是假防御，只有积极防御才是真防御，才是为了反攻和进攻的防御。据我所知，任何一本有价值的军事书，任何一个比较聪明的军事家，而且无论古今中外，无论战略战术，没有不反对消极防御的。只有最愚蠢的人，或者最狂妄的人，才捧了消极防御当法宝。然而世上偏有这样的人，做出这样的事。