Many leading health economists hold misconceived ideas about central components of their work. In particular, they assume that their methods are in principle valueneutral. This belief is demonstrably false. Health economic investigations incorporate mainly unexpressed theories of health. Unless this fact is recognised health economics will shortly reach a conceptual and practical dead end. The way to avoid this dead end is to express implicit theories of health, and explicitly to base philosophically and economically justifiable policy proposals on them.