Complexity of the concept of disease as shown through rival theoretical frameworks.

The concept of disease has been the subject of a vast, vivid and versatile debate. Categories such as "realist", "nominalist", "ontologist", "physiologist", "normativist" and "descriptivist" have been applied to classify disease concepts. These categories refer to underlying theoretical frameworks of the debate. The objective of this review is to analyse these frameworks. It is argued that the categories applied in the debate refer to profound philosophical issues, and that the complexity of the debate reflects the complexity of the concept itself: disease is a complex concept, and does not easily lend itself to definition.