On the one hand, it could be said that China did have an impact on the Enlightenment. It was during the Enlightenment that there came to be a great fascination in Europe with things Chinese, exemplified by the decorative style known as chinoiserie, which sought to reproduce aspects of Chinese architectural and artistic styles, even if somewhat fancifully. Perhaps more significantly, there was considerable interest in Chinese language and philosophy. The exhibition, for example, included the portrait of a German scholar (whose name, unfortunately, I forget) who was known for his study of the Chinese language in the 18th century. Then there was the Chinese philosopher Confucius. Confucius became popular among some figures associated with the Enlightenment (see the accompanying image of an 18th century book in Latin ab0ut Confucius). He was viewed by some as the embodiment of a humanistic, rationalistic philosophy rather like that favored by people like Voltaire, who were seeking an alternative to traditional revealed religion. Indeed, I recall a writer describing Confucius as a sort of "secular saint" for the Enlightenment. The merit-based imperial examination system in China, which tested candidates' knowledge of the Confucian classics, also attracted the interest of some seeking governmental reforms in Europe in this period, a point, incidentally, that is stressed in an exhibit in the museum at Beijing's Confucian shrine (which I have visited a number of times).
On the other hand, one might ask what influence the Enlightenment had on China. This is perhaps not so evident. Certainly, in the 18th century itself, the Enlightenment did not have a discernable impact on China, which at the time was still an absolute monarchy opposed to such Enlightenment ideals as human equality. However, the Enlightenment did have an impact on China in later years, both direct and indirect. Regarding the direct impact of the Enlightenment, according to an article written for the catalogue for the exhibition mentioned above, which is entitled "European Enlightenment in the Chinese Context" (authored by Chinese academics Gao Yi and Xu Qianjin), ideas from the European Enlightenment were taken up by Chinese intellectuals in tbe late 19th and early 20th centuries in their efforts to reform Chinese government and society. As for the indirect influence of the European Enlightenment on China, it could be said that certain ideas that were stressed during the Enlightenment--like human equality and the primacy of science-- had an impact on the development of Marxism. For example, the idea in Marxism that human history can be explained "scientifically" through dialectal materialism seems to reflect the Enlightenment faith in science. Moreover, in the Enlightenment there was a strong belief in the idea of social progress, an idea that is reflected in Marxism (e.g., capitalism will be superceded by morally superior socialism and then communism). Marxism, of course, in turn led to the emergence of Communism (However, there is a certain irony that an exaltation of science and human equality is associated with the Enlightenment and later, with Marxism, since both science and the notion of human equality actually have their bases in Christianity!). Moreover, in 21st century China, "science" continues to hold great prestige (witness President Hu Jintao's slogan kexue fazhan, meaning "scientific development," which also implies the idea of social progress), and the ruling Communist Party continues to hold an attitude toward religion not unlike that of Voltaire, a highly influential figure in the Enlightenment.
And yet...In the midst of Tiananmen Square, where the National Museum of China is located, is the masoleum of Mao Zedong, in which Mao's body is (artificially) preserved, like a Marxist version of a medieval saint of the Catholic church, which Voltaire railed so much against. Furthermore, it was Mao who inspired the Cultural Revoluti0n (1966-1976), which plunged China into an orgy of ideologically-inspired irrationality, in which Mao was treated as a demi-god. And so, in a sense, it could be said that China, under a Communism that had its roots in the Enlightenment, ironically ended up pursuing a course quite in conflict with the Enlightenment's exaltation of "Reason." Perhaps there is a lesson to be learned here--that the efforts of some in the Enlightenment to reject Christianity and to pursue a cult of "Reason" led to a loss of certain moral standards that could have restrained the irrationality and inhumanity so evident in the later stages of the French Revolution, as in the "Reign of Terror." In turn, it can be argued that the French Revolution created the notion of a sort of "revolutionary morality" in which anything can be justified if done for the sake of "the revolution"--a mentality so evident in later Communist revolutions, including China's. Thus, it could be said that China was (or has been) a victim of the dark side of the so-called Enlightenment.