In the effort to control harmful behavior the state uses force against individuals, mainly in the form of detention and, in some places, execution. The Enlightenment, through Cesare Beccaria, gave us a model, sometimes called the Classical Model, for appropriate limits upon those uses of force. The state may use such force, according to this model, but only against individuals who have violated laws set down in advance by the people’s representatives, and only to an extent proportional to the harmfulness of the behavior, an amount also to be decided in advance by the legislature. The model was intended to limit discretion and thereby to limit arbitrariness, and it succeeded (I believe) to the extent reasonably possible. In this book (Rejecting Retributivism) —a book whose many virtues space prevents me from remarking upon in detail—Gregg Caruso proposes an alternative model which I will call the Quarantine Model. In the course of developing that Model he attacks our current system of crime control from two directions: he attacks the retributive base upon which the Classical Model been argued to rest, and he attacks the excesses of the existing system. His arguments on both scores are persuasive, but they do not support his proposed model against a classical, Beccarian alternative. First, the failure of retribution should not be mistaken for a failure of the Classical Model. That Model must be distinguished from the retributive justification that philosophers have attempted to fit it up with. My position in this is (with Caruso) that retribution doesn’t succeed as a justification for the classical approach; that it may be that the classical approach, insofar as it depends upon interfering in the lives of individual offenders, can never be fully justified; but (against Caruso) that it is nevertheless morally superior to any of the alternatives that have been proposed, including Quarantine. Second, it would be a mistake of the first order to suppose that the existing system of crime control is an example of the Classical Model. It is a confused hybrid of both classical measures and preventive measures of the sort Caruso would recommend. I find the current system as deplorable as Caruso does, but I do not consider objections to it to be a sufficient reason for rejecting the Classical ideal in favor of Quarantine. My project here is to set out three concerns about Professor Caruso’s Public Health-Quarantine alternative, which I will refer to simply as the Quarantine Model. The first is that the edges of his model simply cannot be softened in the way he would like to soften them. Both preemptive detention and indefinite detention are essential and ineliminable features of it. The second is that the justification for the model, self-defense and the defense of others, doesn’t seem workable and in particular doesn’t seem to limit the state’s use of detention in the ways he suggests. And the third and most troubling thing is that since we do not get to pick the political setting in which our proposals land, a system of broad discretion such as Professor Caruso proposes is dangerous. It leaves the door wide open to the very sorts of excess that motivated Beccaria to set down his model in the first place.