In the public debates over religion, politics, and morality, isn’t there some rational standard that we all can agree on? Surely there must be a set of common foundations and core first principles from which we can reason together. This is by no means a new question, of course. For viciousness of rhetoric and physical treatment of other human beings, few ages rival the early modern period. In the midst of that age’s battles, Hugo Grotius, the Dutch humanist whose writings have greatly contributed to international law, sought to determine and argue for the core principles of Christianity on which all parties could agree.
The topic was not an abstract one for Grotius. He wrote from the castle in which he was imprisoned by Dutch Calvinists, who opposed his allegiance to a party that sought toleration for dissenters from strict Calvinism.
Grotius also was concerned for many of his countrymen who sailed the world and encountered foreign races and religions. He wanted to write an apologetic for the Christian faith so that they would be well fortified against seduction by error and better equipped to explain Christian truths. The result was The Truth of the Christian Religion, a poem that, upon Grotius’ escape from prison, became a full treatise with exhaustive footnotes. Later it was edited, annotated, and supplemented by Jean Le Clerc and translated into English by John Clarke. Most recently, Liberty Fund has republished Clarke’s edition, edited by Maria Rosa Antognazza, as part of their Natural Law and Enlightenment Classics series.
Grotius divided The Truth of the Christian Religion into six books. The first three offer positive arguments for the truths of Christianity and the last three, critical engagements and comparisons with paganism, Judaism, and Islam. Although Grotius never cites Aquinas, the opening chapters of Book I are a kind of condensed form of his treatise on God at the beginning of the Summa Theologiae. Grotius begins with arguments for the existence and unity of God, as well as God as the uncaused cause in which all created effects are found. He argues for this first on philosophical grounds, then from the complexity and intricacy of the human body and the universe, as well as the suitability of the latter for the former. Grotius also notes the universality of belief in God:
Another Argument for the Proof of a Deity may be drawn from the plain Consent of all Nations, who have any Remains of Reason, any Sense of Good Manners, and are not wholly degenerated into Brutishness. For, Humane Inventions, which depend upon the arbitrary Will of Men, are not always the same every where, but are often changed; whereas there is no Place where this Notion is not found; nor has the Course of Time been able to alter it . . . wherefore we must assign it a Cause as extensive as all Mankind; and That can be no other than a Declaration from God himself, or a Tradition derived down from the first Parents of Mankind. . .
For Grotius, universality is a proof of rationality. All civilized nations and races have believed in a God who serves as first cause. In an impressive display of humanist erudition, he marshals source after source from classical antiquity and world religions, showing how much they agree with aspects of the Christian understanding of God. A creating God is one of the first principles common to all, which only adds to the power of the philosophical arguments in its favor.
Grotius then argues for God’s eternality, omnipotence, omniscience, and perfect goodness. He accounts for evil by human free will and divine action that seeks to punish and reform human beings. He also notes the existence of natural law, “certain Ordinances so universal amongst Men, that they seem so much to owe their Institution to the Instinct of Nature, or the Deductions of plain reason; as to a constant Tradition, scarce interrupted in any Place, either by Wickedness or Misfortune: Of which sort were formerly Sacrifices, amongst holy Rites; and now Shame in Venereal Things, the Solemnity of Marriage, and the Abhorrence of Incest.” Like the existence of God, these principles’ universality gives further weight to the obvious truth that they claim.
Grotius finds further proof for the existence of God from the improbable vicissitudes of human affairs. Given human wickedness, for example, he finds it unlikely that any form of government could survive long without God’s care. Moreover, we have miracles attested to in their own time by credible witnesses. Finally, there is the long continuation of Judaism despite centuries of ridicule and persecution, which can only be explained by the persistent handing on of a faith truly revealed by God. One aspect of Jewish law in particular defies explanation without recourse to divine revelation:
Nor is it in the least credible, that a People of so obstinate a Disposition, could ever be persuaded any otherwise, to submit to a Law loaded with so many Rites and Ceremonies; or that wise Men, amongst the many Distinctions of Religion which Humane Reason might invent, should chuse [sic] Circumcision; which could not be performed . . . without great Pain, and . . . was laughed at by all Strangers, and had nothing to recommend it but the Authority of God.
In Book II, Grotius argues that Christianity is the one true religion. As a contemporary apologist might, he notes the credibility of the Gospels’ witnesses of the resurrection. Unlike contemporary apologists, however, he also argues for the superiority of Christian moral principles and rites in comparison with those of non-Christians. Christianity commands that we worship God with actions that in their own nature are virtuous, not in ritual purity laws and sacrifices. Its core is faith, hope, and love; it is reasonable, not superstitious. Moreover, it argues for the purest and highest forms of morality, especially with regard to marriage. This stands in stark contrast, for example to the Greek philosophers, who “seem to take great Pains . . . to put a virtuous Name upon a vicious thing.”
What about the various disagreements among Christians? Do they not invalidate claims that Christianity is true? No, says Grotius, no more than disagreements between mathematicians disprove mathematics. Since human beings suffer from weakness and prejudice, their judgments will always differ in some way. But in all branches of knowledge, including theology, there are core truths commonly acknowledged. Given the extensive nature of the disagreement, we can be all the more certain of those principles actually agreed upon. Furthermore, Christianity itself is universally acknowledged. It has spread all over the world, through Asia and Europe, Africa and America.
To Grotius’ six books, Jean Le Clerc appended a preface and two more books. These draw political and ecumenical implications out of Grotius’ more apologetic arguments. For Le Clerc, the chief social, political, and theological problem of the day is doctrine. Different sects from different places claim different tenets of faith. They then fight over them, and coerce their fellow men with threats and violence.
Le Clerc’s solution is sola scriptura, a return to the clear teachings of Scripture as the only rule of faith and the only set of beliefs that must be held by all Christians. All should read and study the Bible, coming to their own conclusions with a readiness to revise them as necessary. Every man should judge for himself the truths he finds therein and affiliate himself with a body of Christians that allows him to believe the dictates of his conscience. So confident is he in his method, that Le Clerc predicts a striking result if it were followed: “Were all Christians to go upon this Principle, we should soon see an End of all the fierce Controversies and unhappy Divisions which now rend and confound the Church of Christ: Were every Man allowed to take the Scripture for his only Guide in Matters of Faith, and . . . permitted quietly to enjoy his own Opinion, the Foundation of all Divisions would be taken away at once. . . .” Until then, Christians “ought not to disturb that Peace and Unity which ought to be amongst all Christians, for the sake of any Matters of Faith, any differences of Opinion; because it is contrary to the known Law of Charity. . . .”
Four hundred years later, Grotius’ and Le Clerc’s words are striking. In a way, their arguments have succeeded. Christians no longer kill or imprison each other over doctrinal disagreements. The law of charity and the principle of human dignity offer powerful religious arguments for religious freedom and freedom of conscience. We live in an age where we can all do exactly what Le Clerc advocates: open the Bible, read what lies within, and attach ourselves to whatever sect—if any—most coheres with what we find. That is no small feat and no mean victory.
And yet, of course, their arguments are failing. Sola scriptura and freedom of conscience have not brought the societal and religious unity that Le Clerc predicts. In part, this is because sola scriptura is impossible for human beings. One cannot approach a text without some kind of philosophical or theological presupposition. We do not see the world through neutral lenses, and once we begin to reason, doctrines become inevitable. Moreover, sola scriptura is almost impossible in light of the facts of history. The texts of the Bible have been handed down by religious communities, communities bound together by common doctrinal beliefs. Indeed, the texts that compose the Bible were chosen by those communities because of their authors and because they corresponded to the common doctrinal beliefs held by those communities. Without doctrine and authorities to promulgate it, there would be no scripture to which we could assent.
Furthermore, as the historian Brad Gregory has argued recently in The Unintended Reformation, the turn to the authority of the individual’s subjective interpretation led to exactly the problems that Grotius and Le Clerc claimed it would solve. For if there is no authority higher than a person’s conscience that can adjudicate competing religious truth claims, conflict inevitably results. That conflict is crucial for understanding the nature of the age in which we find ourselves: an age of relativized morality and doctrine, consumerism, state control of religion, secularized knowledge, and the naked public square.
In Grotius’ time, universality was a claim for rationality and Christianity was clearly the most reasonable religion. But Grotius’ criteria of reasonableness come, in part, from his Christianity. Belief in God may still dominate the globe, but in the most “civilized” corners of our world it appears to be withering. Even Grotius’ minimal list of the principles of natural law are now contested.
The Truth of the Christian Religion, then, is more than a marker in the history of Christian thought and its interaction with political and legal philosophy. It serves as a mirror in which to see our own society in light of the past. Indeed, it reminds us that portions of our society really are the anomaly when it comes to belief in a creator and basic principles of natural law. It tells us how we got to our own polarized age, and helps us see what the way back might be.
Religious liberty and freedom of conscience are part of that way back. So is the revitalization of the cultural contributions of Christianity, such as those prejudices that help our reason find honor killings and the exposure of unwanted infants to be irrational and wicked. And, of course, there is what Nicholas Sarkozy and Benedict XVI have called a laïcité positive, a positive secularism that acknowledges the transcendent aspects of the human person. This kind of secularism does not rule out the possibility of human dignity, human nature, natural law, and an Uncaused Cause. It allows us to debate how much these principles can change based on different cultural contexts, and how much they remain the same. An acknowledgement of that sameness and these core principles could resolve our clash of orthodoxies. If we admit them into the conversation, they could once again serve as the foundation on which we order our life together.