Explain the invisibility of organs in humoural anatomy

Study the titles of body organs as well as counting them in the anatomical texts of humoural medicine indicates an important issue: in these texts and in comparison with modern anatomical texts, there is no mention of a significant number of body organs. This is while these two different conclusions are the result of the observations of the same action: the dissection of the corpse. In addition, some of these organs are visible to the naked eye, including lymphatic vessels. Therefore, the humoural physician has seen some organs in the process of dissection, but has not. According to the authors of this article, the reason for the invisibility of these organs lies in the connection between observation and theory. In short, the observation of the humoural physician's dissection practice, unlike the observation of the modern anatomist dissection practice, has been based on the humoural theory. Hence, the humoural physician, in the process of dissection, has seen organs which have a humoural function. The rest of the body organs were either not seen or reduced to a fleshy appendages.