Organon §42
In some cases, as has been stated [§40], nature itself allows two (or even three) natural diseases to meet in one and the same body. However (as one must notice) this complication only occurs with diseases that are dissimilar to one another-diseases which, according to eternal natural laws, cannot lift, annihilate or cure one another. Indeed, it appears that the two (or three) diseases share the organism, as it were, each taking for itself the peculiarly appropriate parts and systems. Because of the dissimilarity of these maladies to each other, this can happen without detriment to the unity of life.