Eric Nelson’s book is the latest addition to a growing number of studies reexamining the relationship of liberalism to Christianity. In recent years, several, sometimes contradictory, arguments have been made. According to Pierre Manent, for example, liberalism began as an attack on Christianity, and he begins his story with Machiavelli and Hobbes. Larry Siedentop, in contrast, sees liberalism as originating in Christianity, and he uses medieval canonists to make this case. In separate books, Brad Gregory and James Simpson argue that liberalism is the unintended consequence of the Protestant Reformation. Each of these narratives defines liberalism in a different way, but they are all critical of liberalism, especially in its modern form. Each author claims that at a certain point in history—the exact date varies among them— something went terribly wrong. There was a loss of meaning, virtue, and human wholeness, and the unfortunate result is the liberalism we have today.

Among these recent histories, Eric Nelson’s is by far the most original. It is also the most complex. Partly this is because his is not a work of traditional intellectual history, but one that aims to bridge what are customarily seen as three separate disciplines: theology, the history of political thought, and normative political philosophy. During the premodern period, Nelson notes, the boundaries between theology and political philosophy were “effectively non-existent” (p. xii). To distinguish sharply between them when studying that period is therefore anachronistic. Moreover, “getting the history right” matters (p. xi) if you want to do good philosophy. This multidisciplinary approach makes Nelson’s book a challenging read for those of us trained in more traditional approaches, but it is also rewarding and well worth the effort.

Nelson’s main argument can be briefly summarized as follows: Anglophone liberalism owes its existence to a Christian heresy called Pelagianism. In the 1970s, however, it took “a fateful wrong turn” (p. xii) because of John Rawls. In his Theory of Justice, Rawls effectively cut liberalism off from its theological roots, thereby rendering it incoherent for all those who followed. More specifically, the arguments that many liberals today make to justify the redistribution of wealth do not hold water. The principle of justice does not vindicate a redistribution of wealth the way Rawls proposed.

The first part of Nelson’s book explains Pelagianism, its influence on “protoliberal” thinkers, and Rawls’s “fateful wrong turn” in the 1970s. Named after Pelagius, a British heterodox theologian of the fourth century, Pelagianism was an attempt to answer the “theodicy debate.” Nelson tells us that the early modern philosophers who contributed most to the birth of liberalism were all involved with this debate. It revolved around a classic question: Is justice just because God wills it (the “voluntarist” position), or does God will it because he is just (the “rationalist” position)? Both the voluntarist and rationalist positions posed problems. By establishing a standard of justice seemingly above or independent of God, rationalism compromised his omnipotence and even risked making him superfluous. But by grounding justice in an act of mere will, voluntarism seemed to turn God into a tyrant.

“Protoliberals” took the rationalist route. They were thus confronted with a number of new problems. If God is both omnipotent and just, how can we explain all the suffering we see in the world? Why would he permit evil? How can we explain the idea of hell? Why would a just God create flawed human beings only to punish them for it? Saint Augustine gave the orthodox answer. Because of original sin, human beings are utterly deformed in their natures and incapable of avoiding sin. They are therefore themselves the cause of evil in the world, and God rightfully punishes them for it. Pelagians, however, denied that human beings are so depraved. They argued instead that human beings are endowed with free will and, by exercising it correctly, can merit salvation from a just God. The evil in the world is simply the price that human beings have to pay for the blessings of freedom. Without it, human beings would not be able to exercise their free will, please God, and be saved. Of course, both of these positions again posed problems. The orthodox Augustinian answer reaffirmed the theodicy problem by essentially turning God into a tyrant. The Pelagian response vindicated God’s justice, but by denying original sin eliminated the need for Jesus. This is likely why few, if any, Christians ever called themselves Pelagian, even when they reasoned as though they were.

“Protoliberals” like Milton, Locke, and Kant chose the Pelagian response. From God’s justice they each inferred that human beings have the freedom to choose the good and thereby to merit salvation. As Milton writes, God trusts man “to be his own chooser.” According to Locke, the path to salvation is through “the voluntary & secret choice of the mind” (p. 19). These thinkers all believed, as Kant asserted, that there had to be “freedom from coercion” for a choice to have any moral value. This also meant that an individual needed a sphere within which to exercise his or her freedom to choose. Nelson rightly reminds us that such ideas were at once theological and political: Locke writes, “Woe to the legislator who wishes to establish through force a polity directed to ethical ends” (p. 20).

It is not difficult for a modern reader to recognize these ideas as distinctively liberal. But Nelson notes that today’s liberals rarely speak in such terms; they no longer speak about merit, freedom, and God quite this way. And this, according to Nelson, is because of John Rawls. Rawls effectively pulled the rug out from under liberalism when he rejected the Pelagian notion of merit. He introduced an incoherence that continues to afflict liberalism.

Before becoming a philosopher, Rawls had planned to become an Episcopal priest. At Princeton University, he studied neo-Orthodox Christian theology and became a convinced anti-Pelagian, as his undergraduate thesis clearly shows. Borrowing language from a long list of Augustinians, Rawls called Pelagianism a “Judaizing” form of pride and, borrowing from Marx, a “bargain basis” (p. 57) view of election. Distressed that “Pelagius rendered the Cross of Christ to no effect”(p. 52), he rejected the idea that human beings could ever merit God’s favor. Rawls eventually lost his religion, but according to Nelson, he never let go of a certain anti-Pelagian disapproval of the notion of merit. He continued to think as if he believed in the doctrine of original sin. We can see this, Nelson convincingly shows, if we look at Rawls’s notion of moral arbitrariness and the role it plays in his philosophy.

A central idea and effectual starting point in his Theory of Justice is that a person’s social position and natural endowments are “arbitrary from a moral point of view.” The idea is that human beings have done nothing to deserve their assets or endowments. Not only their intelligence but also any qualities like industriousness are “morally arbitrary.” Nelson argues that this claim leads to a number of problems and inconsistencies that would plague liberalism after Rawls. For one thing, it essentially sidesteps or even denies the individual’s freedom and thereby results in a contradiction “between liberalism’s commitment to the fundamental dignity of human beings as choosers and the conviction that vast numbers of choices cannot be attributed to human agents in the morally relevant sense” (p. 50). We are led to ask why we should value freedom so much if our choices are morally irrelevant. Until Rawls, the very point of freedom had been to enable merit and thus to vindicate the justice of God.

Having in the first half of the book explained the Pelagian origins of liberalism and Rawls’s anti-Pelagian move, Nelson then proceeds to analyze and evaluate the plausibility of the arguments of those theorists who followed him, whether they are luck egalitarians, “institutionalist” egalitarians, or either left or right libertarians. Methodically, he picks apart their arguments, showing their inconsistencies. Thanks to Rawls, liberals have cast away their long commitment to the idea that individuals are responsible for their fates and have come to see their attributes as the products of mere chance or luck. And yet, strangely, their morally arbitrary endowments are also held to be unjust or unfair, necessitating a certain amount of redistribution from the wealthier to the poorer members of society. This raises many seemingly unanswerable questions, among which are the following: Why are these differences between people’s endowments unfair? According to whom are they unfair? On what basis and how should the “injustice” be repaired? And what would a more “equal” distribution look like? Nelson concludes that post-Rawlsian theorists have taken up “untenable positions” in the theodicy debate, because they have, wittingly or unwittingly, dropped the Pelagian roots of liberalism.

Nelson insists that he is not against redistribution per se. He simply means that a new justification for any redistributive measures needs to be found. The last words of his book are “it is up to us.” Having so masterfully dismantled the reigning justification for redistributive justice, we can only wish that he now uses his extraordinary intellect and vast erudition to help us devise a new one.