In part, I think, Bonhoeffer refrained from writing such a justification because he feared that it might be taken as grounds for resistance in situations less dire than his own: If hard cases make bad law, extreme political situations make bad precedents for everyday ones. And in part, of course, he could not write it because time was not given him by his Nazi executioners. But we may gain an understanding of just how desperate Bonhoeffer saw his situation to be if we examine certain key themes in his writings: his tantalizing and under-developed notion of responsibility, his concept of deputyship, and, especially, his historical analysis of the growth of modern adoration for sovereignty-of the entwining in the Enlightenment of sovereignty over the nation and the sovereignty of the self. We may even gain from such an examination a general understanding of what, for Bonhoeffer, we must render unto Caesar and what we must not.
Bonhoeffer saw himself as a faithful follower of Luther in his refusal of what Germans were asked to render to their terrible Caesar. Any reduction of Luther's doctrine of the "Two Kingdoms" to a notion that there are two spheres, "the one divine, holy, supernatural, and Christian, and the other worldly, profane, natural, and un-Christian," Bonhoeffer held to be a vulgarization. The modern reading of the Two Kingdoms-a reading shaped (Bonhoeffer would say deformed) by the Enlightenment-unwittingly finalized the separation of Christian concerns from the secular and profane. "On the Protestant side," he writes, "Luther's doctrine of the Two Kingdoms was misinterpreted as implying the emancipation and sanctification of the world and of the natural. Government, reason, economics, and culture arrogate to themselves a right of autonomy, but do not in any way understand this autonomy as bringing them into opposition to Christianity." The Lutheran misunderstanding of Luther contributed over time to the Enlightenment cult of reason and the emergence of the self-mastering self.
With that triumph came an idolatrous faith in progress that could only result in nationalism-the "Western godlessness" that became in modern times its own religion. In the "apostasy of the Western world from Jesus Christ," a massive defection from our collective recognition of finitude, we abandoned the knowledge that we are creatures as well as creators. This for Bonhoeffer is the backdrop to twentieth-century totalitarianism, a terrible story of what happens when we presume we stand alone as Sovereign Selves within Sovereign States, a terrible story of what happens when individual hubris meets nationalism.
Bonhoeffer was no simplistic basher of modernity. He understood the impossibility of undoing the Enlightenment and recovering the premodern world. But he believed that we could tame and chasten modern profanations-including the notion that human beings are sovereign masters, unencumbered in their sway. The key seems to be a recognition of the ironic reversal that follows the enthronement of reason. The Enlightenment proclamation of man as the rational master and unlimited sovereign of his own fate contrasts oddly with Nazi invocations of "the irrational, of blood and instinct, of the beast of prey in man," but the Nazi invocations succeeded, in part, primarily because appeals to reason, human rights, culture, and humanity-appeals that "until very recently had served as battle slogans against the Church"-could not succeed in Nazi Germany. For such appeals depended for their success upon a culture upheld by the very Church that had been weakened and compromised. The uninhibited "Will to Power" that constitutes totalitarianism is born from sovereign and unlimited reason, but reason itself gets battered and bloodied when sovereignty goes too far-when it refuses to acknowledge a limit.