Marx and Engels applied the basic principles of historical materialism, and through the analysis of the emergence, development and struggle of the bourgeoisie and the proletariat, profoundly revealed the historical development trend of the inevitable demise of capitalism and the inevitable victory of socialism. The thought of "two necessities" is not derived from the moral indignation of hating capitalism, nor from the beautiful desire of yearning for future communism, but from the scientific understanding of the laws of capitalist economic movement.
The contradiction between socialized mass production and capitalist private ownership determines that capitalist private ownership will be replaced by socialist public ownership. After the capitalist mode of production developed to the stage of machine industrialization, the degree of socialization of production with the socialization of production materials, labor process and labor products as the main contents was increasing day by day. This is an unprecedented progress in the material production of human society. Socialized mass production and capitalist private ownership have always been contradictory. This contradiction is the concentrated expression of the contradiction between productivity and production relations in the capitalist mode of production. The more dominant the capitalist mode of production is, the more it will continue to develop. "The incompatibility between social production and capitalist possession will inevitably become more and more distinct." [1] This basic contradiction, first, is reflected in class relations, which is manifested in the opposition between the proletariat and the bourgeoisie. The bourgeoisie occupies the means of production and regards the means of production as a means of exploiting the hired laborers, while the proletariat divorced from the means of production can only sell its own labor as a commodity and be exploited by capitalists. Second, it is reflected in production, which shows the opposition between the organization of individual factory production and the anarchy of the whole social production. Socialized production requires organized and planned production, but under the condition of capitalist private ownership, organized production can only be realized within enterprises, while in the whole society, production is in anarchy. The capitalist mode of production moves in its inherent contradiction, and the periodic outbreak of economic crisis is the result of this basic contradiction movement. The emergence of the economic crisis shows that the capitalist mode of production has exposed its inability to continue to control this productivity. Therefore, abolishing capitalist private ownership, establishing socialist public ownership and realizing social possession of means of production and products have become the inevitable requirements for the development of productive forces and the socialization of production.
The development of capitalism has created a material premise for the realization of socialism. Because the development of society has already had new economic conditions and class foundation. The new economic conditions are the full development of modern productive forces. Modern productive forces have developed to such a stage that the bourgeoisie occupies the means of production and products, thus occupying political rule, educational monopoly and spiritual leadership, which is not only redundant, but also an obstacle to class, politics and spiritual development. The capitalist mode of production, while developing social productive forces, has also "increasingly turned most residents into proletarians, thus creating a force that has to complete this change under the threat of death." This mode of production increasingly forces people to turn socialized large-scale means of production into state property, so it itself points out the way to complete this change. The proletariat will gain state power and first turn the means of production into state property. " [2]
In addition, Marx and Engels pointed out that some new phenomena in the development of capitalism, such as joint-stock companies, monopoly organizations and state-owned capital becoming the transformation form of capitalist private ownership, have not and cannot fundamentally eliminate the capital attribute of productive forces, so they cannot solve the inherent contradictions of capitalism. Marx and Engels also emphasized that violent revolution is the main way of proletarian revolution. However, they did not absolutize the violent revolution, nor did they deny the possibility of obtaining political power through peaceful means under certain conditions. Whether to seize power by violent revolution or peaceful means depends on different situations in different countries at different times.