Thomas Merton, Origen, and the Christian Case for Peace
See-Judge-Act. Understand our history to better Discern who we are today.
Thomas Merton, Origen, and the Christian Case for Peace
Thomas Merton’s reflections on war begin inside the Christian tradition, not outside it. He accepted that Catholic teaching had long allowed for just war in principle, but he also believed that modern warfare had made it nearly impossible to apply those principles faithfully. For Merton, the question was not whether Christians could ever think morally about the use of force; it was whether twentieth-century weapons had rendered the old moral limits meaningless.
As Merton wrote in Peace in the Post-Christian Era:
“The duty of the Christian in this crisis is to strive with all his power and intelligence, with his faith, his hope in Christ, and love for God and man, to do the one task which God has imposed upon us in the world today. That task is to work for the total abolition of war.”
That conviction helps explain why Merton looked back to the early Church, and especially to Origen of Alexandria. To understand this connection, it is important to consider Origen’s context. Writing in his great defense of Christianity, Against Celsus (c. 248 AD), Origen declared that Christians “no longer take up the sword against nation, nor do we learn war anymore” — a deliberate echo of Isaiah 2:4 — because they had become “sons of peace” through Jesus Christ. Merton saw in Origen a Christianity shaped before empire, before the Church’s entanglement with political power, and before theology had to make its peace with armies. In that older witness, peace was not a private sentiment; it was woven into the Church’s very identity.
Origen was not alone in this witness. Justin Martyr, Clement of Alexandria, Tertullian, and Cyprian of Carthage all stand within a broad early Christian tradition that consistently and strongly leaned away from violence and military service. Justin Martyr, writing around 155 AD, described Christians as people who had exchanged instruments of war for instruments of peace — swords into plowshares, in the spirit of the prophets. Clement of Alexandria said that believers are trained “not in war, but in peace.” Tertullian went further still, arguing in On the Crown (c. 211 AD) that Christ’s command to Peter in the Garden of Gethsemane — “Put away your sword” — symbolized the disarming not just of one apostle, but of Christian life as a whole. Cyprian, bishop of Carthage in the mid-third century, was equally forthright: he found it inconsistent that the world condemns private murder while calling mass killing in war a virtue.
The just war tradition arose when the Church came to inhabit a very different world. The conversion of Emperor Constantine in 312 AD and the Edict of Milan in 313 AD marked a dramatic shift, as Christianity moved from a persecuted minority faith to the empire's religion. With this new relationship to power, theologians — most profoundly Augustine of Hippo in the fifth century, and later Thomas Aquinas in the thirteenth — wrestled seriously with how war might be restrained and governed by justice, rather than left to brute force and unchecked power. That development was historically understandable, even admirable in its intent. However, Merton remained deeply skeptical that just war reasoning could survive the nuclear age intact.
“The root of war is fear.” — New Seeds of Contemplation.
If war can no longer be limited to combatants, if civilian populations cannot be protected, and if nuclear exchange risks the annihilation of entire peoples, then the moral conditions that just war doctrine requires — proportionality, discrimination between combatants and innocents, a reasonable hope of success — cannot be met. In this new era, the logical foundation collapses. Merton did not reach this conclusion with despair, but with a clear-eyed sorrow that he believed the Gospel demanded.
For older Christians who grew up during the Cold War and lived through the anxieties of the nuclear standoff, Merton’s words resonate particularly. He was not a pacifist in a naïve or politically abstract sense. He was a monk who had thought long and hard about human nature, about sin, and about what the Cross actually means for how we live in the world. He understood the temptation to trust in weapons. He understood fear. And he understood that fear, not hatred, is usually where violence begins.
“We are not at peace with others because we are not at peace with ourselves, and we are not at peace with ourselves because we are not at peace with God.” — The Ascent to Truth.
This is the heart of what Merton wanted Christians to hear: that peace is not first a political program, but a spiritual condition. To move from outer arguments to personal challenge, he insisted it begins in the soul before it reaches the world. And it costs something.
“Peace demands the most heroic labor and the most difficult sacrifice. It demands greater heroism than war. It demands greater fidelity to the truth and a much more perfect purity of conscience.” — The Nonviolent Alternative.
Merton’s warning remains urgent because it calls the Church to recover its oldest instinct. The early Church did not begin with a theology of managed violence. It began with Christ, who refused the sword, absorbed the world’s violence upon the Cross, and rose to offer a peace the world cannot give. The first Christians understood themselves as a people formed by that event, summoned into a different kind of power: one rooted in love, in witness, and in the refusal to let fear and hatred have the final word.
For those of us who are older, who have seen wars come and go, who have buried friends and prayed for enemies, Merton offers not easy answers but a serious challenge. In moving from history to personal reflection, he asks whether we have allowed the Gospel to form our conscience on these matters as deeply as it has formed us on others. He asks, gently and persistently, whether we truly believe that Christ is our peace — and whether we are willing to live as though that is true.
“The Christian is and must be, by his very adoption as a son of God in Christ, a peacemaker.” — Seeds of Destruction.
That is not a political slogan. It is a baptismal claim. Drawing together his argument, Merton spent his life asking what it would look like to take it seriously.