Abstract: The semantics of “health” are discussed by way of Aquinas’ theory of analogical predication: “health” and “good” have the tripartite semantic structure in terms of a base use, causes, and signs. This tripartite structure is mapped back onto the discussion of virtue theory, deontology, and consequentialism. T. Horgan and M.Timmon's Moral Twin Earth problem for moral realism is discussed and found not to apply to the present theory. The syntax of biological function statements is explicated and found to have the same underlying structure as prescriptions. A sketch of a theory of the normativity is proffered.

Keywords: analogical predication, function statements, Horgan, moral semantics, Moral Twin Earth, normativity, prescriptions, semantics, syntax, Timmons,