According to the usual academic understanding, classical sociology generally has a broad academic vision and broad theoretical pursuit, and its attention to human moral issues has always been in the core position. They play a very important role in the development of general sociology, especially sociological theory, and Marx naturally cannot be excluded. Isaiah Berlin (1909-1997), a British conceptual historian, believed that no thinker in the 19th century could have such a direct, thorough and far-reaching impact on mankind as Marx. Although the original motivation of Marx and Weber's academic research is to see the practical problems of human society, and based on this, they both put forward a holistic query on the contemporary way of life, and this query points to "capitalism" and makes a critical analysis of capitalism, it is different from Marx Weber's focus on saving the "dignity" of the whole human being, Marx focused his attention on the proletariat, and on this basis, he focused on the liberation of mankind. His social theory is committed to "curing" the problems of capitalist society, which is realized through his critical approach. For Marx, capitalism is a universal "self alienation" that must be revolutionary. The "Irrationality" of capitalism is proved by turning the rational human into inhuman and dehumanizing. Because of this understanding, Marx focused his whole life on the study of the interests of the people. His sharp arguments are always engraved in the minds of himself and His believers. His active, powerful and rational mind has a keen perception of the unfair reality. He and Engels made no secret of pointing out that the bourgeoisie "Submerge the sacred attacks of religious piety, chivalry enthusiasm and the sadness of small citizens in the ice water of egoism. It turns human dignity into exchange value and replaces countless chartered and Self-earned freedoms with a kind of unconscionable trade freedom. In short, it replaces the exploitation covered by religious and political fantasies with open, shameless, direct and explicit exploitation.". This practical and political manifesto with a distinct tendency makes no modern political movement or cause can boldly claim to be better than the Communist Manifesto in terms of literary talent or power, and this work has become a classic document with great deterrence. Even in terms of form, it is also a bold and fascinating "battle call", most of which are in the form of prose. The great revolutionary hymn style passion still has great influence today. In Marx's view, the biggest problem of capitalism is that its mode of production rules and distorts the way of communication between people. Therefore, the way to solve this problem is to re-establish the way to dominate their mutual communication, which must be based on changing the existing capitalist system. From this point of view, the ultimate goal of "humanized" liberation that Marx tried to achieve is definitely not in the legal sense, but the pursuit of a real humanitarianism. Starting from the whole appearance of capitalism, we will find that although the modern capitalist society appears to exist for human survival, in fact, it only exists for the bourgeoisie. Such a society will inevitably lead to the alienation of human beings. To eliminate human alienation, only the political and economic liberation of individual people is far from enough. It must also involve the liberation of "human beings". It is on this point that there are obvious differences between Marx and Feuerbach. Marx believes that the production relationship formed in the production process is the most essential relationship between people. Religion can only be rooted in the contradiction of society itself. The history of human social development is naturally the history of material production development. Marx's criticism of modern economy, society and politics always points to the core of human alienation. The economic expression of this problem is "commodity and its world", the political expression is the contradiction between "society" and "state", and its direct social expression is the existence of "proletariat". From the perspective of human nature, no matter the proletariat or the proletariat, what they represent is the Defamiliarization between man and himself. The proletariat, as a class forced to alienate itself and externalize itself like a commodity, if they can consciously realize that they have been deprived of everything, they will develop a class consciousness and critical revolutionary consciousness, and overcome the existing differentiation through hard struggle. Unless the proletariat liberates the rest of society at the same time, it will not be able to achieve self liberation. In capitalist society, the proletariat is the class with the most serious self alienation. It is only a "commodity" with personality, and can only express its existence in the form of "commodity". Therefore, the proletariat is the core of social problems. In this way, the simple economic problem has become a "political economy" problem, as well as human survival economy and people's class consciousness and human consciousness for this survival economy. The next thing to think about is, why did Marx criticize the capitalist society? We believe that answering this question must be combined with the function of Marx's social theory. It should be pointed out that the social criticism of Marx's theory has the function of scientific interpretation and far-reaching construction. The methodology of Marx's social criticism is not only the unity of affirmation and negation, but also the unity of criticism and constructiveness. We should not simply think that the criticism of Marx's social theory is its ultimate goal, but also clearly recognize the constructiveness of Marx's social theory, which always hopes to find and construct a new, more reasonable and just world in criticizing the old world. Some people accuse Marxism of attributing everything in the world to economic factors, so it is just a form of economic determinism. In fact, in a sense, few people can challenge the obvious fact that "all phenomena are economic phenomena". Marx emphasized the extreme importance of material production, not only because there would be no modern civilization without material production, but also because the process, nature and result of material production will ultimately determine the development process and basic nature of civilization. When "production for production" becomes the creed of a society, the society's understanding of "production" must be one-sided and narrow, and human self realization will be impossible, while Marx's understanding of the concept of "production" is much broader. The same is "production", which is a concept in the pure economic sense in the capitalist society. In Marx's view, "production" itself is far beyond the pure economic scope, including all creative or artistic human activities. Therefore, although Marx pays attention to economic issues, it does not mean that he is simply obsessed with economic issues. In the world he expects, economic activities will no longer occupy so much of our time and energy. It is in this sense that Marx will pay attention to human development and enjoyment and human free and all-round development. In his opinion, a better society is not work but leisure, "self realization" is also a kind of "production". Human self realization is our future goal and high-level pursuit, but this kind of production should not be based on coercion. It can be seen that the critical meaning of Marx's theory lies in the construction of an orderly society at a higher level. Only in this way can we better understand why "two centuries have passed and great and profound changes have taken place in human society, but Marx's name is still respected all over the world, and Marx's theory is still shining with dazzling truth!" (Xinhua News Agency)