[The decline and emergence of diseases]

Presenting the various approaches that have so far been employed in the historical study of diseases, the author analyzes their characteristics, points to their limitations, and emphasizes their complementarity. In most cases historians restrict themselves to studying diseases separately, one by one, failing to bring to light reciprocal influences. After defining the concept of pathocenosis, the author examines some of the diseases prevalent in the pathocenoses of former days. He also describes the historical path taken in the conceptualization of diseases.