Two reasons were given. First, in about one-third of all cases, a patient recovers from his or her condition even without treatment. For these cases, they argued, it would be inappropriate to credit acupuncture. In other words, students might well recognize on their own that to assess the effect of the needling alone, you would need to compare patients treated with acupuncture with those who received no treatment. Chinese medicine stresses the result for the patient.
Research is secondary.
Therefore, you would not withhold a treatment just for the sake of a test. For the traditional Chinese, if you already knew how to help a patient recover, you did not also need to know why the procedure worked, especially if your research would likely cost patients their well-being. While a Chinese scientist might not disagree with the reasoning behind the design of the controlled experiment, it would be outside proper science. At the same time, Chinese doctors did not distinguish so sharply between psychological and physiological mechanisms. The treatment itself was effective.