Engels's thesis on marriage has several major flaws: First, he believes that the matriarchal system of early human beings was determined by "the importance of women's labor for the survival of the tribe, and they produced the vast majority of goods, such as clothing, household goods, and tools", and he ignored that "no accumulation of wealth" was the main source of the matriarchal system. Because, even in the matrilineal era, human beings also rely on physical strength to survive, men's physical advantage is innate, this physical advantage determines that men in the matrilineal era will never create less wealth than women. In the matriarchal age, the chief of the tribe and the main creator of wealth should still be male, as we can attest from the animal world. Now people confuse matriarchy with matriarchy, but in fact, matrilineality does not equal feminism. Second, he argues, once the only driving force behind deciding marriage is love, the monogamous family system triumphs in the end. He did not realize that human nature is polymorphic, and once love became the sole driving force of marriage, a marriage of pure love was more unstable than a marriage of co-production, which was determined by the instability of love. Third, Engels emphasized material production in his determinism of production, ignoring the special contribution of women in man's own production. Engels's Origins does not analyze women's emancipation from the point of view of human reproduction. Fourth, Engels attributed the low status of women to the fact that domestic work was borne by women, so many people thought that as long as society advocated that domestic work should be shared by men, it seemed that women could be liberated. In fact, the attribution of domestic work is not a fundamental difference between men and women. With the development of society and the further refinement of the social division of labor, housework can be completely separated from the family and undertaken by specialized domestic service personnel, and do not need to be borne by wives or husbands. The fundamental difference between men and women is that the physical advantage of men is innate, and the reproductive resource advantage (clear offspring) possessed by women is also innate. In the two major productions of material production and man's own production, the innate superiority of women determines the superior position of women over men in man's own production; in the era of material production by physical strength, men's innate superiority determines men's superior position in material production. Once the era of material production by intelligence replaces the era of creating material by physical strength, the dominant position of men in material production is bound to decrease, the traditional equilibrium relationship between the sexes in material production and human production is broken, and the marriage system will inevitably change. (To be continued)