In this blog post, we examine whether Korean medicine’s core theories—the Yin-Yang and Five Elements theory and Sasang constitutional medicine—possess scientific evidence from the perspective of Popper’s falsificationism.
When I was young, wanting to be even a little taller, I visited a Korean medicine clinic run by a famous practitioner featured on TV for a while. Before making a diagnosis, they conducted several tests to determine which traditional Korean medicine ingredients would suit me. The tests were simple. First, I would lie down, and the practitioner would place a traditional Korean medicine ingredient on my solar plexus. They would then measure the strength in my arm using their own arm. Based on the strength measured, they would determine whether the ingredient was suitable for my body or not. At the time, I remember finding the entire testing process fascinating and believing everything the practitioner said without question. However, ultimately, I didn’t grow any taller, and it became the catalyst for me to start questioning traditional Korean medicine.
Traditional Korean medicine is a medical system that has developed in Korea since ancient times. It is also referred to as Eastern medicine in contrast to Western medicine and has evolved through exchanges with the medical systems of other countries in East Asia. Traditional Korean medicine views the human body as a microcosm, so its foundational theory is the Yin-Yang and Five Elements theory, centered on the cosmic principle of Yin and Yang. The natural worldview of traditional Korean medicine, the principles of human physiology and pathology, and theories regarding diagnosis, treatment, and medicinal substances are all explained through the Yin-Yang and Five Elements theory.
The Yin-Yang and Five Elements theory is the most fundamental and crucial theory underpinning traditional Korean medicine. Here, yin and yang refer to a fundamental system applied when observing any object. It means recognizing the relative differences by observing the essence of things as either yin or yang, even though their fundamental nature is the same. For example, the exterior of the body is yang, while the interior is yin; the upper and lower parts belong to yang and yin, respectively. Furthermore, physiologically, the rise of heat and blood pressure is considered yang, while the drop in blood pressure and slowing of the pulse is considered yin. Thus, yin and yang interact to maintain regulation. When this relative equilibrium is disrupted, problems arise, and restoring this balance is the task of Korean medicine.
Meanwhile, the Five Elements refer to wood, fire, earth, metal, and water, which compose the universe. Like yin and yang, these five elements also maintain balance through a cyclical process of generation and destruction. Traditional Korean medicine utilizes the principles of mutual generation and mutual restraint within the Five Elements to resolve pathological phenomena. For example, the liver and heart are in a mutually generating relationship, while the liver and spleen are in a mutually restraining relationship.
However, these foundational principles of traditional Korean medicine cannot be falsified by Popper’s falsificationism, so traditional Korean medicine can be defined as unscientific. This paper will argue that traditional Korean medicine is unscientific by presenting several key aspects that are unscientific. First, from the perspective of traditional Korean medicine, every part of the human body can be corresponded to yin and yang. It claims that health is achieved when this yin-yang harmony is attained, and disharmony can be resolved through traditional Korean medicine. However, the assertion that the human body is composed of yin and yang is highly unscientific.
For example, if illness is attributed to a deficiency of vital energy (原氣) in the body, then every disease can be explained by this vital energy. This theory could account for everything from a mild cold to diseases like cancer. Yet, because such a theory is impossible to verify, it is unscientific. Furthermore, Freud’s theory also falls into this category. His theory that “sexual desire” is the cause of behavior is an unscientific claim because it cannot be disproven. In the early 20th century, Freud proposed a theory that mental illnesses could be resolved through psychoanalysis. He stated that traumatic memories from past experiences are trapped deep within the unconscious mind. These memories do not disappear completely but remain submerged in the unconscious, influencing consciousness and behavior in various forms. Therefore, to heal mental illness, he argued that these submerged memories must be retrieved and reintegrated with current memories to achieve healing. However, in modern times, his psychoanalytic theory has been criticized as unscientific and belonging more to the realm of humanities than medicine.
From this perspective, the claim that the human body is composed of yin and yang is a highly unscientific assertion. For example, consider a patient with a fever and high blood pressure. According to yin-yang theory, this patient has a problem because yin energy is stronger than yang energy, disrupting the yin-yang balance. To treat this, Korean medicine attempts to reduce the yin energy. The problem is, there is no way to know whether this treatment actually reduces yin energy or, conversely, strengthens yin energy while reducing yang energy. Even if it does reduce yin energy, there is no way to know by how much. Like the saying “hang it on the nose, it’s a nose ring; hang it on the ear, it’s an earring,” one can explain any disease in terms of the relative strength of yin and yang. Yet, much like Freud’s theory mentioned earlier, this offers only retrospective explanations; it is not a method for predicting the future or providing solutions. Moreover, contrary to the known Yin-Yang theory, if we consider the body’s interior as Yang and its exterior as Yin, and interpret fever and rising blood pressure as Yin while falling blood pressure and slowing pulse as Yang, everything can be explained identically. Thus, it is a theory impossible to disprove under any circumstances. Similarly, the Five Elements theory is also impossible to disprove. Consequently, the Yin-Yang and Five Elements theory, which forms the foundational basis of Korean medicine, can be considered unscientific.
Examining the Sasang Constitution Medicine, founded by Jeong Yim in the late Joseon period, makes the impossibility of falsification even more evident. Sasang Constitution Medicine classifies human constitutions into four types—Taeyang-in, Taeum-in, Soyang-in, and Soeum-in—and posits that diseases should be treated according to an individual’s specific characteristics. It claims that even for identical symptoms, the therapeutic effect is maximized only when treatments tailored to each person’s constitution are applied. However, the very notion that human constitutions can be divided into four distinct types is inherently impossible to disprove. For example, according to Sasang medicine, among the four constitutions, the Taeeumin type is described as having more fire and less water compared to other types, based on the theory of Yin-Yang and the Five Elements. The very concepts of “fire” and “water” used here are highly abstract, making them impossible to disprove. Moreover, the criteria used to distinguish Tae-eum-in from other constitutions—having a large liver and small lungs—are highly ambiguous. Furthermore, the physical description of Tae-eum-in, which states they are robust and often overweight but can also be thin, is so broad that it could include anyone, making it impossible to disprove.
Finally, I wish to discuss the unscientific nature of Korean medicine’s treatment methods. While Korean medicine employs various treatments, the most well-known is acupuncture. The principle behind acupuncture is described as aiding the flow of qi and blood through the treatment of meridians. The qi and blood referred to here are energy sources that supply energy to the organs, and it is said that this concept was conceived from wisdom gained in daily life. However, this qi and blood is inherently unverifiable, making falsification impossible. Like the earlier theories of original qi or Freud, this too is an unscientific theory.
This text has discussed the unscientific nature of Korean medicine from three perspectives. First, it was shown that the Yin-Yang and Five Elements theory, which forms the foundational basis of Korean medicine, is unfalsifiable. Second, it refuted the Sasaeng medicine derived from it, and finally, it addressed acupuncture, the representative treatment method of Korean medicine. Thus, unfalsifiability emerged in several elements representative of Korean medicine, making it a non-scientific medical practice. Of course, while not covered in the main text, some elements of Korean medicine might be falsifiable from Popper’s perspective. However, as mentioned earlier, the fundamental principles and representative treatment methods that define Korean medicine are unscientific. This leads to the conclusion that Korean medicine is unscientific. Therefore, this paper hopes readers will keep this in mind when choosing between Western medicine and Korean medicine for future treatment.
