My Medical Philosophy: Medicine's Core Task Is to Resolve the Body's "Excess" and "Deficiency"

The Way of Heaven—Is it not like bending a bow? What is high is lowered; what is low is raised. What has excess is reduced; what is deficient is supplemented. The Way of Heaven reduces the excessive and supplements the deficient.

The way of humanity is otherwise: it takes from the deficient to offer the excessive. Who can offer what is excess to the world? Only one who possesses the Way. Therefore the sage acts without presumption, accomplishes without dwelling on it, and does not wish to display his worth.

—From the Daodejing

1. TCM's "Excess and Deficiency" and the Western Doctrine of Homeostasis

Medicine's ultimate mission is not merely to destroy a specific pathogen but to restore order within the living system. Whether Eastern traditional medicine or modern Western medicine, its core task can be reduced to the precise intervention and correction of the body's "excess" (taiguo) and "deficiency" (buji). This correction of imbalance is not only the path to curing disease but the fundamental principle of preserving human dignity and quality of life.

In the philosophical language of Chinese medicine, "excess" and "deficiency" are regarded as the fundamental mechanisms of disease. Huangdi Neijing summarizes this pathological state: "When yin is preponderant, yang is diseased; when yang is preponderant, yin is diseased"—i.e., an excess or deficiency of the two internal forces of yin and yang breaks the original harmony.

To address this imbalance, TCM establishes the treatment principle: "Carefully observe where yin and yang lie and regulate them, seeking balance as the goal." Here "balance" is not absolute stillness but dynamic equilibrium—the ideal state of "yin well-pasted and yang well-secured, where spirit is at peace" described in Suwen's "Shengqi Tongtian Lun."

When the body shows "excess," reduce what is redundant; when it shows "deficiency," supplement what is lacking. This wisdom of correction is deeply rooted in ancient Chinese philosophy. The Daodejing says, "The Way of Heaven reduces the excessive and supplements the deficient." Medicine emulates the Way of Heaven, using human intervention to guide the body back to the path of "central harmony," so that qi and blood are harmonized and the zang-fu organs are at peace.

Not coincidentally, modern Western medicine, in exploring the laws of life, has independently arrived at a core idea highly congruent with "excess and deficiency": homeostasis.

The development of homeostasis theory is a history of deepening human understanding. As early as the mid-19th century, French physiologist Claude Bernard proposed the concept of the "internal milieu," pointing out that the internal environment of multicellular organisms (blood, tissue fluid) must remain relatively constant as the prerequisite for free and independent life. This idea laid the cornerstone of homeostasis theory.

In the 1920s, American physiologist Walter Cannon built on Bernard and formally coined the term "homeostasis," elaborating it systematically in his 1932 book The Wisdom of the Body.

Cannon emphasized that homeostasis is not rigid fixity but a dynamic "similar but unchanging" regulatory state. When internal or external disturbances push physiological variables such as body temperature, blood glucose, or blood pressure outside the normal range (i.e., producing "excess" or "deficiency"), the body automatically activates negative-feedback mechanisms, drawing these variables back to the set normal range through the coordinated action of the nervous and endocrine systems.

For example, when blood glucose is too high, insulin secretion rises to promote glucose uptake and storage; when blood glucose is too low, glucagon promotes liver glycogen breakdown, maintaining glucose homeostasis.

With the introduction of engineering cybernetics in the mid-20th century, Norbert Wiener's negative-feedback theory gave homeostasis a precise mathematical and engineering language, moving medicine's understanding of "excess and deficiency" from qualitative description to quantitative models.

Today the concept of homeostasis has expanded from the internal milieu to whole-body systems and even molecular-level network regulation. Many modern treatments are essentially helping the body restore homeostasis: antihypertensives correct "excess" blood pressure; insulin replacement compensates endocrine "deficiency"; anti-infective therapy removes external disturbances to homeostasis.

In sum, whether the Eastern wisdom of "seeking balance" in Huangdi Neijing or the Western science of "negative-feedback regulation" in modern medicine, they tell the same truth: life is a complex system striving to maintain its own balance in a dynamic environment. Medicine's core task is to be that system's assistant and repairer—sharply perceiving and correcting structural and functional "excess and deficiency," and ultimately guiding life back to harmony and homeostasis.