From Frank Dikotter:
Intermarriage between select races was seen as a key to reform. In 1898 Yi Nai actively advocated racial fusion (hezhong) as a means of strengthening the Qing. Although he anticipated intermarriage with the white race, unions with the inferior ‘black’ and ‘red’ races were to be abjured. The diplomat Wu Tingfang also pronounced himself in favour of mixed unions: ‘There is no doubt that mixed marriages between the white and the yellow races will be productive of good on both sides.’ Tang Caichang advocated blending the white and yellow races, for it was only through ‘racial communication’ (tongzhong) that China would flourish again. He advanced ten arguments in support of intermarriage:
(1) The exuberance of flowers and plants was the result of their original union. Giant prehistoric trees that had failed to merge with other varieties had disappeared after natural catastrophes.
(2) Bees and butterflies were the matchmakers of nature. They contributed to the blooming of flowers by transmitting pollen from one variety to the other.
(3) Zoologists had proved that the nature of animals could be enhanced by environmental and dietary change. In the Age of Great Peace, the world would be open to exchange, the mean would be ennobled, and the unruly would become tractable. In times of trouble, people lived in insularity, devoured by envy and hatred for different people, debased by an evil nature.
(4) In ancient times, marriage within the lineage had been prohibited. This principle was in accordance with the idea of racial exchange. Only people isolated by high mountains and deep valleys could not flourish and quickly disappeared.
(5) Between the five continents, there was a general flow of political, artistic, military and economic exchanges. Why would racial exchange not follow?
(6) The Japanese recognised the strength of the European race and the weakness of the Asian race: their government sanctioned the practice of intermarriage.
(7) In Hong Kong, Singapore and the Pacific islands, intermarriage between Chinese and foreigners had produced offspring of unparalleled intelligence and strength.
(8) Although England, Russia, France and Germany all maintained national borders and nurtured mutual distrust, their citizens were free to intermarry.
(9) Buddhism believed in a pervading spirit uniting all living creatures.
(10) Intermarriage was not confined to the treaty ports alone: even several high officials had taken Western wives.
Tang drew upon botany, zoology, history and even Buddhism in his defence of race contact. Thus far, however, his arguments lacked an essential element: an indigenous cultural trait on which the idea of racial exchange could be grafted. Tang continued his dissertation by opposing two foreign bodies of learning. On the one hand, proponents of evolution believed in the theory of natural selection and the elimination of the unfit. Exponents of physiology, on the other, considered that with the progress of medicine and science, the weak could be cured and the evil transformed. Evolution corresponded to Xunzi’s theory of man’s evil nature. Physiology was compared to Mencius’ teachings on the innate goodness of man. Whereas Xunzi upheld justice (yi), Mencius supported humanity (ren). Only the latter, however, suited the ‘One World’ (datong), an age of equality in which racial communication would inevitably follow other forms of communication. Mencius sanctioned racial amalgamation: only if the white and yellow races merged would the strength of the yellow race be enhanced, in accordance with Confucianism.