Not overtly siding with Patočka's diagnosis of modern malaise, Derrida is very attentive to the sort of dialectic genealogy in Patočka's essay. He particularly focuses on the ways in which the development of this sense of responsibility is also a maintenance and iterative encryption of a secret, through its orgiastic/daemonic, Platonic, and Christian stages. "Because of this incorporation that envelops demonic or orgiastic mystery, philosophy remains a sort of thaumaturgy even as it accedes to responsibility" (15).
The second chapter has Derrida turning more often directly to Heidegger as an immediate influence on Patočka, as well as to Levinas as a critic in the same tradition. In its third chapter, The Gift of Death spends a great deal of attention on Kierkegaard's Fear and Trembling and sacrificial responsibilty in the context of Patočka's essay. Derrida comes closer, I think, than Kierkegaard does to the real mystery of "the sacrifice of Abraham," as a failed transmission of the initiation of Isaac. But he uses Kierkegaard's language to bootstrap into the fourth and final chapter.
Derrida drives toward his conclusion with a set of reflections on the nature and significance of invisibility--the same invisibility of the Greek lord of the dead (aides-Haides), the unspeakable issuer of commands to Abraham, and the "Father" of Jesus "who sees in secret." Attentive Thelemites may glean some important perspective here on the doctrine of the Knowledge and Conversation of the Holy Guardian Angel in the place of "the heart." And there is also, here and earlier, worthwhile integration of the concepts of sacrifice, secrecy, and the sacred.
At various points in the book, Derrida seems temporarily to accept some sort of theological claims, but he is careful to allow not to demand such acceptance from the reader (e.g., 69). And at the very end he invokes Nietzsche's Genealogy of Morals (which was always behind Patočka's genealogy of responsibility) as a background for observations about "the reversal and infinitization" that exalts the other ("God," if you must) into mystery (115). There is, after all, no law beyond Do what thou wilt. The Christian God sacrifices himself "from love (can you believe it?)" taunts Nietzsche. And Derrida drops the mocking tone to ask whether one truly can, leaving me to wonder what such a possibility of dis/belief can portend if love is the law.
"What does it mean to share a secret?" Derrida asks more than once. Only those who know how to die could tell, and they won't say.