The distinctive feature of Yan Fu’s theory of population was his pioneering analysis of China’s population problems through the application of Darwin’s theory of the survival of thefittest to the survival of races. Yan beIieved that the deciding factor in the cycle of social stability and unrest was fluctuation in population. He also proposed "two complimentary theories of reproduction": the "theory of education reducing births" and the "theory of interracial marriage improving offspring. " Yan maintained that human beings must exercise selfcontrol over reproduction, and he advocated eugenics to raise the quality of the population and reduce its rate of increase. Yan Fu’s theories, although inappropriate in some ways,were on the whole rational, and they provide some useful guidance for contemporary familyplanning.
