Detailed Instructions: Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.
Q: Passage: Western medicine was also practiced in China by the Nestorian Christians of the Yuan court, where it was sometimes labeled as huihui or Muslim medicine. The Nestorian physician Jesus the Interpreter founded the Office of Western Medicine in 1263 during the reign of Kublai. Huihui doctors staffed at two imperial hospitals were responsible for treating the imperial family and members of the court. Chinese physicians opposed Western medicine because its humoral system contradicted the yin-yang and wuxing philosophy underlying traditional Chinese medicine. No Chinese translation of Western medical works is known, but it is possible that the Chinese had access to Avicenna's The Canon of Medicine. Question: What aspect of Western medicine did the Chinese dislike?
A:
its humoral system