Some things, but only some things, are by nature subject to standards. Why? I explain and develop what I call nature-first constitutivism, which says that what something is determines what it should be. Nature is the basis of normativity. I explain this view in terms of a unique type of property which particulars of a genus can lack even though those properties partially determines the nature of the genus. Such properties partially describe the nature of a genus and are thereby (...) normative for the particulars of that genus. Particulars of genera with such essential properties are by nature subject to standards with respect to those properties. Particulars of genera without such properties are not by nature subject to standards. (shrink)