• aetiological naturalism
• biostatistical naturalism
• disease
• functional definitions of disease
• health
• health and disease debate
• hybridism
• pragmatism

This dissertation focuses on the concept of somatic disease as it has been discussed in a longstanding controversy within the philosophy of medicine: i.e., the health and disease debate. More specifically, this dissertation deals with functional definitions of the disease concept, namely, theories aiming to define the concept of disease via functional considerations. These theories are: biostatistical naturalism (Chapter 1), aetiological naturalism (Chapter 2), and hybridism (Chapter 3). What I have contended is that each these functional approaches encounters the same underlying issue; there are diseases that cannot be captured as such on the conditions introduced for making disease attributions, that is to say, there are some states that cannot be characterised as pathological based on the necessary, sufficient, or jointly sufficient conditions that similar functional theories provide, which undermines the entire project of defining the concept of disease based on preconceived, a priori specified notions of function and dysfunction.