In the world, democracy and science are only fruits of the tree of freedom. In the west, especially in Britain and the United States, the achievements of democracy and science have been produced more than two centuries ago. Democracy and freedom are inseparable. Democracy is first and foremost the freedom to vote in elections and the right of citizens to freely express their political views. Science is also inseparable from freedom. Without full freedom of scientific research, it is difficult to have scientific research results. Scientific spirit is essentially free spirit. Only where there is the most personal freedom is the most developed science. Scientific research is the personal affairs of independent and free researchers. Personal freedom and autonomy are the premise of scientific research. The strength of a country is directly proportional to its freedom, and the prosperity of science is also directly proportional to the freedom of scientists in scientific research. Even if some people notice the importance of freedom, they just regard "democracy, science and freedom" as a trinity and inseparable. This view is wrong. Freedom, democracy and science are not parallel at the same level, nor are they equally important, but are causal. Freedom is the foundation of democracy and science. Mr. De and Mr. Sai are brothers. They are all sons of liberty. Without a fully free social environment that guarantees freedom of thought, science will stop, at best, it is only a technical imitation; If there are no free individuals, there will be no freedom and democracy in which individuals can engage in free political activities. No one has any objection to the development of science, even dictators. Under the dictatorship, people's free scientific exploration was suppressed. Science is a science that is empowered and serves the ruling machine, and it is a science that crawls in front of political power. Power says what is science and what is science. This kind of science embezzled people's well-being, disintegrated individual's freedom and crowned the ruler's power. In a free society, science is first and foremost a personal and folk science, which is a tool to increase people's well-being. With a free system, science will develop automatically; Without a free system, science can't develop, so it can't revitalize the country. One of the main drawbacks of power-led science is that it compresses the space of folk scientific research, occupies the battlefield where creative ideas are free to gallop, and turns the independent scientific research activities of folk multi-centers into dependent scientific research activities with power as the single center. Under the national scientific research system, scientists have no freedom to explore and no right to discover the truth. Its task is not to discover the truth, but to realize the political pursuit of the rulers and complete the scientific research tasks entrusted by the system as a political task. An independent personality must obey political demands. However, the basis of scientific research is the spirit of free exploration. Once this spirit is locked in the iron cage of bureaucrats, it cannot be brought into play. Scientific research, like economic activities, also needs a fully free market environment for individuals, and the government cannot interfere, let alone lead. Most of the major scientific discoveries and inventions in history are the achievements, demands and wisdom of the people. The role of the government is to create a free environment for scientific research, rather than taking scientists and scientific research as the object of giving orders. To develop science and technology, we don't need a planned national system, but we need to stimulate the initiative and let researchers freely imagine, study and debate. It should be pointed out that behind the appeal of "democracy and science" in the May 4th Movement, the group is higher than the individual, and the state is higher than the individual. The individual is only a tool to achieve the goal of collectivism. The country or nation is the goal, and the individual is just a tool. To commemorate the May 4th Movement is not to deny it, but to surpass the height it has reached. We can't simply repeat the slogan of democracy and science, and regard democracy and science as the ultimate means to solve all the problems facing the country. Many people say that China's problem is, in the final analysis, Mr. De and Mr. Sai's problem! No, what I want to say is that the question of China is fundamentally a question of freedom. If this problem is not solved, there will never be a place for Mr. Desai. Some people may ask, what happened to democracy and science? I said, democracy and science are good. The key point is that people can never fully enjoy the benefits of democracy and science without full personal freedom. Where individuals enjoy full freedom, democracy and science can take root. Therefore, if the people of China want democracy and science, they must change from believers in democracy and science to believers in personal freedom; From caring about the fate of the country to caring about the fate of the individual; From yearning for democracy and science to yearning for individual freedom; From longing for fruit to sowing hard. We must realize that the needs of the people of China are higher than those of China, and the needs of China must be subordinate to those of the people of China. It is possible to seek the fruits of democracy and science on the premise of starting from the individual rather than the country and starting from the freedom of the individual rather than the power of the country! The experience since the May 4th Movement, the slogan of democracy and science, tells us that if we want democracy and science, we must first pursue personal freedom. Freedom is the key!