 Problems arise at several different levels with this more recent S-naturalism, though all are traceable to the reliance on the new theory of reference. To begin, there are familiar reasons to be skeptical about whether the new theory of reference is correct, reasons that won’t be rehearsed here (see, e.g., Evans 1973, Blackburn 1988). Even granting, however, the correctness of the new theory, it is not obvious how it helps in the case of law. After all, the new theory always seemed most plausible for a limited class of expressions: proper names and natural kind terms. The reason has to do with the implicit essentialism required for the new theory: unless referents have essential characteristics—just as “water” has a distinctive and essential molecular constitution—they cannot fix meanings. But what is the essence of “due process” or “equal protection?” And what is the “essential” nature of the many artifact terms that populate legal rules (terms like “contract” or “vehicle” or “security interest”)? Unsurprisingly, S-naturalists like Brink and Moore are also moral realists, and also try to give accounts of artifact terms as picking out not “natural kinds” but “functional kinds” (Moore 1992a, pp. 207–208).