This anthology of essays presents a sample of studies from recent philosophy of medicine addressing issues which attempt to answer very general (interdependent) questions: (a) what is a disease and what is health? (b) How do we (causally) explain diseases? (c) And how do we distinguish diseases, i.e. define classes of diseases and recognize that an instance X of disease belongs to a given class B? (d) How do we assess and choose cure/ therapy?0The book is divided into three sections: classification, disease, and evidence. In general, attention is focused on statistics in medicine and epidemiology, issues in psychiatry, and connecting medicine with evolutionary biology and genetics. Many authors position the theories that they address within their historical contexts.