You shall surely reprove your fellow. Leviticus 19:17 A long time ago, I spent a couple of years reading Calvinist theology and Puritan treatises and sermons (for a doctoral dissertation and a first book).I don’t remember many lines, but one has stuck in my mind. The Reverend Richard Baxter, author of The Holy Commonwealth, described in 1659 how he maintained moral discipline in his Kidderminster parish “with the help of the godly people of the place who thirsted after the salvation of their neighbors and were in private my assistants.” I have thought a lot about those godly people and their peculiar “thirst.” There aren’t all that many men and women so strongly engaged with their neighbors’ moral well-being, but such people do appear frequently in history. We find them again and again “thirsting” after the salvation, or the rectitude, or the piety, or the political commitment, or the ideological correctness, of their neighbors. These people possess what I want to call “moral concern.” (There may be a better term.) They are driven not only to worry about the moral rightness or wrongness of other people, but also to express their worry — sometimes only in private, but sometimes also in public. Moral concern is my subject here. You might call it nosiness, but that word carries negative connotations that are too quick for my purpose. Anyway, moral concern goes far beyond nosiness: it is not just an interest in other people’s beliefs and behaviors or a readiness to talk about them; it is also an eagerness to improve both. Moral concern is different from compassion, which describes a sympathetic engagement with other people’s physical or material well-being — with those who are sick or poor, or victims of flood or fire, or orphans, battered wives, disabled men and women. And moral concern is also different from solidarity, which requires a commitment to help people who are oppressed or, better, who are resisting oppression, fighting for national liberation or racial or gender equality. Solidarity leads political activists to join the fight, to support the goals of the fighters. By contrast, the agents of moral concern are not committed to the goals of other people; they have their own goals. They have a very firm idea about what my moral condition should be, which probably isn’t my own idea. They thirst after my religious or political salvation. And their thirst may well challenge or even override my self-concern and my liberty. I haven’t looked for help in the analysis of moral concern from the philosophical psychologists, who may well have a lot to say about these thirsty people. I am a political theorist, and I will consider the role that morally concerned men and women have played in political history. In line with contemporary practice, I should say up front that I believe that moral concern often leads to moral over-reach, and that it has had perverse effects, especially in left politics, but not only there. At the same time, isn’t there something admirable about people who think not only about themselves but also about others, who worry about you and me? This concern for the morality of others begins, I think, with parental solicitude — and also parental anxiety. Both of these are no doubt salutary: we want parents to worry about the morality of their children and to work hard to teach them right and wrong — not only how to behave but how to think about how to behave. But doing and not doing comes first, as in this injunction to parents from a seventeenth-century Puritan text on “family government.” The young child which lieth in the cradle [is] both wayward and full of affections: and though his body be but small, yet he hath a great heart, and is altogether inclined to evil…. If this sparkle be suffered to increase, it will rage over and burn down the whole house. For we are changed and become good not by birth, but by education…. Therefore parents must be wary and circumspect, that they never smile or laugh at any words or deeds of their children done lewdly…naughtily, wantonly…they must correct and sharply reprove their children for saying or doing ill…. A high level of moral concern would be required to follow this disciplinary program. It is, perhaps, an extreme example — or, better, given the politics of seventeenth-century Puritanism, a revolutionary example. It calls on parents to enforce a radical discipline. And it tells us two important things about how concern for the morality of others works when it becomes a project. The project begins with the conviction that the men and women about whom we are concerned are in a bad state — perhaps not utterly depraved as in Puritan theology, but seriously wrongheaded — religiously, politically, ideologically incorrect. We are “wary” about the others, sure that they need help. And then our concern is expressed in clear-cut ways: we help the others by sharp reproval and firm correction. But if we move from children to neighbors, the concern will have to be expressed a little less sharply. Parents have full control over their children; when children “run wild,” family government has failed. Our neighbors, by contrast, are free men and women, so when we exercise our moral concern we are likely to engage in some version of what the Puritans called “brotherly admonition.” Still, admonition is shadowed by the hope for something stronger, something more like firm correction. Early seventeenth-century Puritans might urge their neighbors not to attend frivolous and wanton performances of Shakespeare’s plays, but their ultimate goal was to close the theaters. So moral concern reaches toward politics — from family government to the government of the state, from admonition to coercion. The most obvious example of official moral concern is state censorship: subversive or licentious books and magazines are banned in order to make sure that no one in the country gets subversive, dissident, or wanton ideas. Subversive ideas are not