What is the fundamental difference between 大同世界 and Utopias
Tl;dr: Terms that share apparently similar meanings but are each specific to their own culture should not be considered as synonymous.

The reason for incomparability is that the context or purpose of the two usually differs. E.g., the Chinese concept of zhongyong (中庸, doctrine of the mean) should not be equated with the Aristotlean concept of the golden mean, which 'also' refers to a desirable middle between two extremes. While some of the examples in the golden mean may overlap with Confucian virtues, the Aristotlean golden mean is intended to be a solution in ethics, i.e., how to be ethical (i.e., doing the ‘right’ thing) between two vices (say being courageous between cowardice and recklessness), in order to achieve 'happiness' (eudaimonia) in life. Zhongyong is simply an advice on the Way of life, does not provide concrete examples like its Aristotlean analogue, and does not aim to achieve eudaimonia. That is to say, 中庸 is not an ideal translation of the Aristotlean golden mean.

Here I argue datong (大同), despite its seeming overtness in literality, is in fact culture-specific. It is classically a Confucian concept first appearing in The Book of Rites (禮記) (sadly a fact overlooked by many) and is juxtaposed to another societal form, xiaokang (小康) (note: NOT the modern meaning). Both datong and xiaokang societies seem ideal and harmonious (utopian, if you may), but datong is the better of the two. Why? Because people in datong aims for the common good (天下為公), and there is spontaneity in their practicing the Confucian principles (e.g. 仁義 and 五倫). That is to say, these principles need not be deliberately advertised or codified into laws and rules, as in a xiaokang society. In fact, Confucius was expressing regret in the obsoletion of a datong society, as he considered the society he was in a xiaokang one.

The modern use of datong as we know it originates from Kang Youwei (康有為). Kang's Datong shu (大同書) outlines the hypothetical datong society where radical compassion (Kang's interpretation of 仁) should be applied to all. In Smith (2019):



In The Great Unity ([D]atong shu), Kang discussed the future datong as a
utopia in which states will no longer exist; families will be
completely different, as men and women will be equal and same sex
marriage will be accepted; robotic birds will take the place of
servants; and animals will be treated well by a world of vegetarians.
Although often full of radical compassion in a way unlike other
literature of his contemporaries, Kang and his book were products of
their time, and included terrifying prescriptions for the elimination
of the black race through a centuries-long programme of eugenics.
Kang’s utopia was both highly imaginative and deeply troubling.


Kang's datong society was not exactly that of the Republic of China, but it is definitely utopian. A utopia must be imaginary (Thomas More intended it to be imaginary when he first coined the term; it comes from Greek οὐ 'not' and τόπος 'place' which translates as 'no-place') and contrasted to the flaws of the existent society. It also depends on the ideals of the thinker, so there may exist a plethora of utopias. The universalisation of English has perhaps also made its use loose and diverse. On the other hand, the concept of datong, be it Confucian or Kang's, is relatively stable (despite both being imaginary like utopias, with the Confucian one being historical, and de novo in Kang's). That is to say, utopia is an umbrella term. There are similarities and differences between datong and utopia; equating the two terms is not sound.

Similarly, 理想國 is technically a type of utopia. Classically it is the title translation of Plato's Republic, but in modern speech the specificity has decreased and has become similar to meaning utopia.


Reference: Smith CA. Datong and Xiaokang, in Sorace, Franceschini, Loubere (eds) Afterlives of Chinese Communism. AUS; 2019.