Organon §6

All the perceptible signs, befallments and symptoms of disease represent the disease in its entirety.

The unprejudiced observer, even the most sharp-witted one-knowing the nullity of supersensible speculations which are not born out in experience-perceives nothing in each single case of disease other than the alterations in the condition of the body and soul, disease signs, befallments, symptoms, which are outwardly discernible through the senses. That is, the unprejudiced observer only perceives the deviations from the former healthy state of the now sick patient, which are:
1. felt by the patient himself,
2. perceived by those around him, and
3. observed by the physician.
All these perceptible signs represent the disease in its entire extent, that is, together they form the true and only conceivable gestalt of the disease.

Comm: I do not know [am not aware] how physicians at the sickbed could suppose that they ought to seek and could find what was to be cured in disease only in the hidden and indiscernible interior, without paying careful attention to the symptoms or being precisely guided by those symptoms in their treatment. I do not know [am not aware] how they could be so ridiculous and presumptuous as to attempt to discern what has changed in the invisible interior of the body without paying much attention to the symptoms, or how they could attempt to set it right again with unknown(!) medicines and then call this the only thorough and rational treatment. The medical-art practitioner can never see the spiritual wesen, the life force, that creates the disease, and he never needs to see it. In order to cure, he only needs to see and experience its diseased effects. Therefore, in the eyes of the medical-art practitioner, is not that which reveals itself to the senses by disease signs the disease itself? What else is the old school looking for in the hidden interior of the organism as a prima causa morbi while at the same time rejecting and haughtily disdaining the disease presentation that is clearly perceptible to the senses, that is, the symptoms that audibly speak to us? What else do they want to cure in disease but these symptoms?