AbstractWith the increasing awareness of the involvement of genetic factors in disease, questions arise as to what distinguishes genetic from non‐genetic disease, and what constitutes a genetic susceptibility. A general framework, reflecting the structure of biological explanations, is presented in which such distinctions can be made. We conclude that such distinctions are objective and are based on the biological facts; they are not “social constructions” nor do they presuppose resolution of philosophical problems regarding causation. © 1994 Wiley‐Liss, Inc.