ICD-11, 2019: a two-thousand-year-old vocabulary entering the international disease classification.
Qi
The vital, material energy that constitutes and animates everything - not a substance things are made of, but the activity they are.
- Theme
- Being and reality
- Tradition
- Chinese
- Term
- 氣 · qì
- Term fixed
- c. 320 BC
In plain terms
European thought asks what things are made of and answers with stuff - atoms, matter, particles. Chinese thought asks the same question and answers with something closer to activity: qi, which starts out meaning breath or steam and ends up meaning whatever it is that condenses into things and disperses again.
The difference matters. Stuff sits there and needs a separate story about why anything moves. Qi is already in motion, so what needs explaining is not change but why anything holds together long enough to be a thing.
Translating it as energy is the usual shortcut and it is wrong in a specific way. Energy in physics is a quantity that things have. Qi is not had by anything - it is what there is, in a denser or thinner state.
As a philosopher would put it
Qi is neither matter nor spirit, and the failure of both translations is a fact about the categories rather than about the term. It condenses into visible things and disperses at their dissolution; Zhang Zai's formulation is that its condensation and dispersion are as necessary as ice forming and melting on water, so that nothing is created or destroyed.
In Neo-Confucianism qi is one half of a pair. Zhu Xi's synthesis makes li, principle or pattern, and qi jointly necessary: li is why a thing has the nature it has, qi is what gives it concrete existence and turbidity, and moral failure is explained as impure qi obscuring a nature that is good. The Lu-Wang school disputes the priority, and the later kaozheng scholars attack the whole framework as an accretion on the classics.
The term also carries a medical vocabulary of long standing - circulation, blockage, depletion - and a cultivation practice that is older than either the medicine or the metaphysics.
Where you meet it
In 2019 the World Health Organization published ICD-11, and for the first time the international classification of diseases contained a chapter of traditional medicine diagnoses. Codes were assigned to patterns like qi deficiency and qi stagnation, drawn from a nosology that has been in continuous professional use for two thousand years.
The reaction was immediate. Editorials in Nature and Scientific American objected that the categories have no biomedical referent; the WHO's answer was that the chapter records what practitioners actually diagnose, that hundreds of millions of consultations use these terms annually, and that a classification which cannot count them cannot study them either.
Both sides are describing the same fact. Qi is doing organising work in a live clinical vocabulary, and there is no agreement on what kind of thing it is - whether a physiological variable not yet identified, a way of describing patterns of function, or a piece of metaphysics that outlived its physics.
What is actually disputed
What kind of term it is.
One reading treats qi as a failed physical hypothesis: an early theory of matter and energy that was reasonable before there was chemistry and has been superseded. Another treats it as a functional and relational vocabulary that was never in competition with physics, describing patterns of process at a level physics does not address - in which case asking what qi is made of is a category error.
The argument is not only between traditions. The kaozheng scholars of the seventeenth and eighteenth centuries attacked the Neo-Confucian qi-and-li framework from inside the Chinese tradition as a Buddhist-influenced accretion, and modern New Confucians have defended and reconstructed it. What almost nobody now holds is the position that would make translation easy - that qi is simply a name for energy in the physicist's sense.
Commonly confused with
- life force Qi is in stones, weather and the air as much as in organisms. Restricting it to living things is a nineteenth-century European reading.
Defined against
- Matter Qi is what there is in a denser or thinner state; matter is what things are made of. The two answer the same question in incompatible grammars
Philosophers
Works
- Zhuangzi Where the condensation and dispersion picture is set out
- Reflections on Things at Hand The Neo-Confucian synthesis, in its standard anthology
- Daodejing The source vocabulary
- Instructions for Practical Living The Lu-Wang objection to the priority of principle
Schools
- Daoism (Dao-jia) Where the term is at home
- Cheng-Zhu School Where it is paired with principle
- Lu-Wang School of Mind Where the pairing is disputed
- Evidential Learning (Kaozheng) Where the whole framework is attacked from inside
- New Confucianism Where it is reconstructed in the twentieth century
Related concepts
Matter c. 330 BC · Li (principle) c. 1175 · Yin and yang c. 300 BC · Becoming c. 500 BC · Nature c. 330 BC
The word means breath or vapour and is much older than any theory; the Warring States texts turn it into a general account of what things are, and Zhu Xi later pairs it with li as the two halves of an explanation.