We saw on pages 173–183 that disease, as a resemblance category, is a social construct in that it is a society-relative category whose prototypes are established by that society. In the present chapter, we will explain and substantiate this thesis. It will be argued that prototype diseases, as focal generators of the category disease, are deontic-social constructs emerging from particular ought-to-do rules of a society. To this end, we shall introduce four notions upon which our conception is based, i.e., the notions of common morality , deontic institution , deontic set , and deontic-social construct .