The practical science of medicine.
Contemporary medicine, it is argued here, employs reductive explanations, but at the same time resists wholesale reduction to "deeper" biochemical and physical fields or theories. In its own reductive explanations, to be sure, medicine borrows causal concepts from other fields and so necessarily shares certain explanatory goals with those deeper fields. However, because medicine has additional, distinctive goals as well as a special subject matter and problems (it is a practical science), the field of medicine is ultimately irreducible.
D000755:Anemia, Sickle Cell / Q000209:etiology; D006801:Humans; D008511:Medicine / Q000639:trends*; D008954:Models, Biological; D009369:Neoplasms / Q000209:etiology; D010686:Philosophy, Medical