For the period of savagery, group marriage; for barbarism, pairing marriage; for civilization, monogamy, supplemented by adultery and prostitution.

• 群婚制是与蒙昧时代相适应的，对偶婚制是与野蛮时代相适应的，以通奸和卖淫为补充的一夫一妻制是与文明时代相适应的。