No one should accuse Oliver O’Donovan of tackling easy topics. In The Desire of the Nations (Cambridge University Press, 1999) he defended an idea most of us thought was dead and buried: Christendom. The dominant liberal attitudes of our time celebrate pluralism, including religious pluralism; we wouldn’t want to go back to the narrow old days when Christianity dominated society. Stanley Hauerwas and his friends rejoice that as a supposedly embattled minority, Christians can now stand up for what they believe much more easily than they could when they carried the burden of theirs being the whole culture’s more or less official religion. Until O’Donovan, professor of moral and pastoral theology at Oxford, everyone seemed to agree that Christendom—the idea that Christian faith should shape the secular order—was a bad idea.

But Christians, O’Donovan argued, ought to engage in mission—in trying to convince the world of the truth and value of the gospel. Suppose we managed to convince our political leaders and a majority of our fellow citizens. Should we be embarrassed by our success and hasten to insist that we didn’t really want people to listen to us? Or should we rejoice that Christian ideas would now help to shape our political culture? (O’Donovan wasn’t talking about a “Christian America” run by Pat Robertson, but about a nation guided by real Christian values.)

Old-fashioned liberals from Milton to Mill, O’Donovan pointed out, valued intellectual diversity because it helps us find the truth. The combat among different ideas helps lead us to the right answer. He worried, however, that nowadays people celebrate diversity for its own sake, as if actually finding truth or even finding agreement would be some kind of tragedy. But suppose we did agree on how society ought to be organized, and suppose that agreement rested on Christian principles. Should Christians find that so terrible?

Hauerwas would reply that Christianity would then sell its birthright, compromising its principles for power. Well, maybe, O’Donovan would answer, but are Christians so obviously independent-minded now in our non-Christendom culture, or do we sell out just as quickly to “the commonplaces of the stock exchange, the law courts, and the public schools”? Pluralists would worry about the oppression of non-Christian minorities. But a truly Christian polity would, on Christian grounds, not oppress. Indeed, it would be willing to let itself be supplanted, recognizing that political entities come and go, while only the church endures.

O’Donovan’s new book, a sequel to The Desire of the Nations, has no similarly surprising central thesis, but in its own way it is at least as bold. Desire was a work of theology, exploring what Christian theology has to say about politics. The Ways of Judgment is a work of political theory, systematically addressing from a Christian perspective the kinds of questions political theorists tackle. It is an application to political theory of what H. Richard Niebuhr called “Christ the transformer of culture.” O’Donovan protests that too much recent “political theology” (liberation theology would be one example) assumes that we know the right answers about politics and should use them to resolve the ambiguities of Christian theology. On the contrary, he contends, it is contemporary political reflection that is an incoherent mess, and it is the gospel that offers some clear answers that could really help.

In rich dialogue with both political thinkers and the Christian tradition, O’Donovan addresses many of the traditional topics of a course in political theory: justice, equality, authority, legitimacy and so on. What governments do, he says in part 1, is judge. Every government action, from making laws to waging war to setting up schools, is an act of moral discrimination that makes a judgment about the right and wrong of what we have done and what we ought to do next. Making such judgments requires political institutions—the topic of part 2—and Christians have to think about the relation of those institutions to the church, as discussed in part 3.

At every stage O’Donovan offers challenging conclusions. Writing about judgment, for instance, he reflects on how punishment, in principle, has three possible beneficiaries: the victim, the offender and the society. Victims get revenge; offenders get rehabilitation; society gets protection from future crimes as one criminal is locked up and others are deterred. “In Christian thought, however, the victim’s benefit was removed from consideration.” Revenge is simply not an appropriate goal for Christians, and therefore rehabilitation and the future protection of society are the only acceptable goals when we punish. The fact that today we set up ways for victims or their families to watch executions and testify in favor of more severe sentencing is “a measure of the deep de-Christianization of our times.”

If that sounds like a solidly liberal position, O’Donovan has little patience with liberals like John Rawls who define justice as no more than the compromises that enable us to live in peace by giving us the freedom to pursue our various visions of the good without interfering too much with one another: “There could undoubtedly be worse tyrannies than that of the regnant liberal secularism, so sensitively averse to overt physical suffering. That much must always be said in its favor. But what cannot be said for it is that it fosters freedom. For in attempting to dictate what is true on the basis of what is convenient, it shuts down the human calling to the knowledge of the truth.” When Rawls and others encourage us to tolerate each other’s differing goods, they simply give up on the quest for the good. O’Donovan thinks human beings are driven to look for a true good and to try to convince everyone else when we find it, and we are deprived of an important freedom if we are told we can’t do that.

Freedom, O’Donovan insists, doesn’t mean the liberty to wander wherever one will: “Without adults who demand mature behavior, the child is not free to grow up; without teachers to set standards of excellence, the scholar is not free to excel; without prophets to uphold ideals of virtue, society is not free to realize its common good. To be under authority is to be freer than to be independent.” If no goals are ultimately worthwhile, then I am not free to pursue an ultimately worthwhile goal—and that is a terrible loss of freedom.

Freedom thus flourishes best under authority, O’Donovan argues. But authority isn’t the same thing as power. Those who truly have authority recognizably stand for what is right and for a shared tradition, the two elements that make up the common good. It was said of a legendary dean of students at my college that he could break up a riot just by showing up. He had authority. Whether in the classroom or in the political realm, those who try to keep order with constant threats and punishments turn to power because they lack authority.

Authority guides society, and O’Donovan says society is defined by communication in the old sense of the word—communication that includes all sorts of sharing, not just the sharing of information. In contrast to recent discussions about the nature of “the gift” in the work of Jacques Derrida, John Milbank and others, O’Donovan’s argument focuses on this sharing. What creates a community isn’t that mine becomes yours (giving) but that mine becomes ours (sharing). Thus, O’Donovan argues (idealistically, I think), once early Christianity “taught its slave-members to regard their ‘masters’ as brothers who depended on their help,” it created a kind of community that ultimately doomed the institution of slavery. The challenge for our time, he goes on, is to find an analogous way to experience business transactions as community-building rather than purely commercial. Can I as buyer and you as seller think of ourselves as part of a common enterprise, with shared goals and the obligation to help each other as needed?

O’Donovan is hard to classify with the usual political categories. Like Pope John Paul II, he is committed to social justice in ways more liberal than almost any current American politician, but he also notes as an example of unjust laws “those that permit unborn children to be unnecessarily killed by their mothers with the assistance of gynecologists.” Though he never mentions the name, O’Donovan puts me in mind of F. D. Maurice, that 19th-century British advocate of both church tradition and the poor who was H. Richard Niebuhr’s favored example for his concept of “Christ the transformer of culture.”

I am relieved to encounter an eloquent account of “Christian values” that doesn’t call for hating gays and assassinating the president of Venezuela. But does O’Donovan face the sad history of “Christendom” rigorously enough? So often when Christians have dominated the political realm, we have persecuted Jews, denigrated women and started crusades. Those who have the greatest political success just now while waving a Christian banner would seem unlikely to do much better if they had more power. I do see O’Donovan’s point: as we share the gospel with the world, it’s absurd to worry that we will persuade too many people. But shouldn’t we worry about what would happen if we succeeded?

What would Christendom of the sort O’Donovan envisions look like? Years ago, at the height of the cold war, Harold Hughes, a devout Christian who was then a senator from Iowa, said that if the Soviets launched all their nuclear missiles, he would not retaliate. By the standards of the gospel it would be better that the aggressor nation survive than that both be destroyed. By saying this, he admitted, he probably disqualified himself from ever being elected president. I agreed with him about what a Christian ought to do, and many agreed with him about the resulting disqualification.

Reinhold Niebuhr reminded us that getting involved enough in politics to do some good involves compromising one’s principles. He would have argued that Hughes should have run for president and kept his mouth shut about hypotheticals. Like Niebuhr, O’Donovan thinks we ought to get involved, but he seems less worried about the compromises we’ll have to make. Christianity, he says, “restrains the thrust for judgment; it points beyond the boundaries of political identity; it undermines received traditions of representation; it utters truths that question unchallenged public doctrines. It does all these things because it represents God’s kingdom, before which the authorities and powers of this world must cast down their crowns, never to pick them up again.” Amen. But I’d sure like to know more about how that would work in practice.