Edwaert Collier, Vanitas, 1663.

I nearly deleted it.  The email’s subject line was “FoulMatter”—an obvious Internet phishing scheme, I thought. A Russian heiress was embroiled in some “foul matter” and needed my Social Security number so she could deposit money into my account for safekeeping? A Nigerian prince requesting initial investment in “a guinea foul farm”?

No. That wasn’t it. The email was from my publisher, from the heart of my publisher—the editorial department. Now I really didn’t want to open it. Maybe I’d missed a deadline.  Maybe they’d changed their mind about my contract. Or found an error so grievous they were recalling my books. Or found a new and more appropriate term for my writing.

“Dear John,” the editorial assistant had written, “would you like to keep your foul matter from American Philosophy: A Love Story?”

My foul matter? As if I had a choice. American Philosophy, published last year with Farrar, Straus and Giroux, is a memoir about facing a father’s death, a divorce and a remarriage, and how American philosophy (the writings of Emerson, Thoreau, and William James) helped me survive. I am now in the weeds of writing my second book, another hybrid of memoir and intellectual history, this time about parenthood and Friedrich Nietzsche. If I’ve learned one thing it’s that you are largely stuck with yourself, most especially with your foulest parts.

Foul matter, it turns out, as I learned by reading the rest of the note, is the inevitable literary flotsam that is generated in writing a book—the notes, page proofs, drafts, and rejected covers and art. Michelangelo once described the process of sculpting as the art of removing stone until a beautiful form emerges from a block of granite. If writing is at all like this, foul matter is the stuff strewn across the studio floor. The question remained: Did I want it?

Not really. For someone in the midst of writing, the foul matter is a reminder of how much work is left to be done: most of the wordsmithery that goes into drafting a book runs the very real risk of being scrapped. This is the case for any—or at least most—books, but the foul matter for a memoir, I suspected, was especially disturbing. It wasn’t just literary detritus, it was a spare part of myself. The French philosopher and writer Simone de Beauvoir writes, “What an odd thing a diary is: the things you omit are more important than those you put in.” That might be true, but they’re usually omitted from a diary or a memoir for good reason, and the reviewing of foul matter was a willing return to something that I’d tried to leave behind.

But perhaps I was avoiding something important. Nietzsche wrote eighteen autobiographical essays before he reached middle age. In his later years, whether through intellectually bravery or sadomasochism, he returned to them repeatedly as a way of analyzing what he had become and how he had become it. The earliest stories about himself were vitriolic screeds against his idol-turned-mortal-enemy: the Romantic composer Richard Wagner. Wagner had, according to the young Nietzsche, done him and Germany and music tout court wrong. Wagner’s music lacked nuance and grace. Wagner’s music was “sick.” Wagner’s music invited idolatry and patriotic zeal rather than genuine aesthetic appreciation. In truth, Wagner had turned on Nietzsche and spread rumors about his personal life, and the young philosopher hated him for it.

As Nietzsche grew older, however, he returned to his harsh critique of the composer and, as many angry people do upon reflection, tempered it: “All things considered,” he writes in Ecce Homo, his final attempt at autobiography, “I could never have survived my youth without Wagnerian music. For I seemed condemned to the society of Germans. If a man wishes to rid himself of a feeling of unbearable oppression, he may have to take to hashish. Well, I had to take to Wagner … ” At the same time, in the late 1880s, Nietzsche was beginning to articulate an important kernel of his philosophy known as the amor fati, the love of fate. To neither evade nor bear but to ardently love what one once found most objectionable about life—this is the imperative of the amor fati.  It is to affirm and accept what one once denied or escaped. In Nietzsche’s words, “I shall be one of those who make things beautiful. Amor fati: let that be my love henceforth! I do not want to wage war against what is ugly. I do not want to accuse; I do not even want to accuse those who accuse. Looking away shall be my only negation.” Looking away is the only thing that is forbidden and undesirable.

“Sure, send the foul matter,”  I wrote, almost against my will.

Minutes later, I received the response: “I will mail it off today. Most authors throw it away, but you have a nice amount. Definitely on the larger side.” 

Great.

It arrived in three giant packing envelopes, which, after being retrieved from the front step, remained unopened on our kitchen table for a week.  My five-year-old daughter eyed one of them carefully at breakfast one morning and, once she finished her toast, once the dishes were cleared and the room was empty, opened it. When I returned, my foul matter was spread across the table where we ate. The most objectionable piece was a bound manuscript titled Finding West Wind. Four years ago, I’d proudly taken it to a bindery before placing it in the mail to my editor. She sent it back to me, thoroughly annotated—“This is somewhat juvenile,” “This sounds a bit petulant,” “This writing is not acceptable”—with the brief note that I should try writing it again. That’s how good it was.

The writer’s “foul matter.”

And then there was the draft of A Wilderness of Books: American Philosophy, A Love Story. By that point, I’d nearly given up on the idea that the book would ever exist. The pages of my manuscript were loose and dog-eared and now decorated with a child’s markers. It was even more heavily annotated: “This title is not working,” “This needs tightening,” “Losing the thread,” and the very occasional “Good.”  But this time there was no brief note at the end: I didn’t have to write the whole thing again. I could put away the hacksaw. What I needed was the scalpel and to clean up behind myself. The manuscript—this memoir—was still too self-involved.

“Of all that is written,” Nietzsche tells his reader, “I only love what has been written in a man’s own blood.” The point of writing, if I understand Nietzsche correctly, is to cut it close—to put your real no-bullshit self on paper. But it is also to suffer. At one point, in the not-so-distant past, I’d cherished these rumpled pages as the most accurate renderings of myself. In the process of writing, however, one sometimes has to sacrifice the self-knowledge that one thinks he or she already has.

Editing is not a matter of “murdering your darlings” but sacrificing them so something else can take their place. The traces of mistakes and failed attempts haunt many books, but the best authors, like Nietzsche, incorporate them into the vibrancy of a literary corpus. “I have often asked myself,” Nietzsche writes, “whether I am not more heavily obligated to the hardest years of my life than to any others.” An author is similarly obligated to the failures in the course of writing, the mistakes that allow a book to become what it is.

As I perused the penultimate draft of American Philosophy: A Love Story, I found a note that was absent in earlier versions: “stet,” from the Latin stare, “to let stand.” I’d become accustomed to reading the tight cursive of my respected editor, so I didn’t recognize the handwriting at first—my own. This was my first successful effort at pushing back, insisting that something should stand instead of being cut away. This stet indicated a phrase—just four short words—that would find its way into the finished book. What doesn’t kill you, according to Nietzsche, makes you stronger. Maybe even strong enough to work through your foul matter and learn to let it stand.

John Kaag is the author of American Philosophy: A Love Story (2016), which was published in paperback this month, and Hiking with Nietzsche, which will be published in 2018.