The logic of planning and the aim of the law

In his recent book, Legality, Scott Shapiro argues that laws are plans. Very similar views have already been developed by Finnis. But Shapiro's version does nothing to accommodate the status of a legal order as a form of association within which force may ordinarily be employed only against those who have violated the law. Shapiro seeks to reconcile his legal positivism with the thesis that law necessarily has a moral aim. But his argument for this thesis contains an equivocation which is fatal to its validity.