Works that change how literature is written are few and far between. Georg Büchner’s novel “Lenz,” published posthumously in 1839, is one of them. Though Büchner died, unknown, of typhus at 24 in 1837, the Modernist emphasis on interiority he established runs straight through to Dostoevsky, Kafka, Hemingway, Camus, Beckett, W.G. Sebald and Elfriede Jelinek. Without Büchner, fiction as we know it would be unthinkable.

Works that change how literature is written should also change the way we read. To this end, Richard Sieburth’s forceful and exacting translation of “Lenz” not only is presented in a beautifully produced bilingual edition, but it also provides the historical material from which Büchner concocted his intense fictional portrait of three weeks of madness suffered by J.M.R. Lenz (1751-92), a playwright and member of Goethe’s circle.

The result is a fresh and unique reading of this classic, one quite akin to what Sieburth describes as Büchner’s own “brilliant (post-) modernist experiment in intertextuality.”

The inspiration for this novel was an account written by Johann Friedrich Oberlin titled “Mr. L…,” which Sieburth includes here. Büchner, in fact, swiped whole passages from it, lifting one-eighth of his story verbatim without any mention of Oberlin. The result does not so much reveal the abuse of Oberlin, the Alsatian minister who tried to care for Lenz, but rather Büchner’s own genius.

For it is what Büchner leaves out—namely, the immediate context that gives rise to Lenz’s madness—that causes the author to supply an interior reality never before seen in a fictional character.

Consider, for instance, Oberlin’s account of Lenz delivering a sermon before Oberlin realizes he is mad: “I went to the altar, said the absolution, and Mr. L. delivered a pretty sermon from the pulpit, although perhaps with too much trepidation.”

Here, on the other hand, is Büchner’s rendering of the same moment: “The pressure within him, the music, the pain, shook him to the core. The universe was an open wound; it caused him deep nameless pain. Another existence now, the quiver of heavenly lips bending down over him and sucking on his; he returned to his lonely room.” Trepidation indeed: The answer to whose “heavenly lips” those are or just what shape that other “existence” takes in Lenz’s wounded mind is never given, only suffered. The power of Büchner’s text stems from the fact that it is told in the third person, but most often from Lenz’s own perspective.

In addition to Sieburth’s inclusion of Oberlin’s original account, the translator contributes an extended passage from Goethe’s autobiography, “Poetry and Truth,” in which the great poet blandly says, “Of all the full- or half-time idlers intent on digging into their inmost depths, Lenz excelled in cultivating and perpetuating this state of conflict, and thus he suffered in general from the tendency of the age to which the depiction of Werther was meant to put a stop &.” When compared with such condescension, the pathos of Lenz’s private suffering is deepened in Büchner’s text.

“One has to love mankind in order to penetrate into the unique existence of each being,” states Lenz, though Büchner makes clear that this is not a task for the weak of heart. Meanwhile, it is Sieburth who has given us “Lenz” in an edition that is a model for how translation can help reveal the complex anatomy of a great work of art.

Peter Filkins is the translator, most recently, of a new edition of Ingeborg Bachmann’s collected poems, “Darkness Spoken.”