Five years ago, in Reality Hunger: A Manifesto, the writer David Shields articulated an anticonfessional notion of self-disclosure as a means of pursuing conceptual insight: “What I believe about memoir is that you just happen to be using the nuts and bolts of your own life to illustrate your vision.” His recent book—I Think You’re Totally Wrong: A Quarrel, co-authored with a former student, Caleb Powell—experiments with the machinery these “nuts and bolts” might build. It’s an edited transcript of an intimate argument spanning a long weekend that the pair spent together in a cabin in the woods in Washington State. As they wrestle over the Yeatsian choice of “perfection of the life, or of the work,” their conversation is full of self-disclosure that feels less like confession and more like trial evidence. The dialogue is strategically literary: their plan is “to come out of this with a book.” In Ongoingness, her third foray into memoir, Sarah Manguso offers another kind of structural challenge to the traditional confessional style. She describes an 800,000-word diary she kept for 25 years, but never quotes from it. Which is to say that she narrates the process of narrating her own life, rather than tapping the more predictably confessional vein of the diary itself. Both books offer a vision of personal experience as something intellectually constructed rather than nakedly exposed; in their pages, revelation is a mode of self-scrutiny rather than a plea for absolution or attention.

Manguso’s 800,000 words could probably fill a dozen books—but she never wrote her diary to be read, she says, and eventually decided that “the only way to represent the diary in this book would be either to include the entire thing untouched … or to include none of it.” Instead, with a kind of anti-prolix purity, she evokes the diary in lean abstractions and polished reflections that elide or condense the experiences that shaped them. Her prose feels twice distilled; it’s whiskey rather than beer, writing about writing about life. Many of her short blocks of text swell into aphoristic closing beats trailed by the gently understated exclamation point of white space.

“I didn’t want to lose anything,” she writes of her need, as a younger woman, to document everything she lived and felt. “Imagining life without the diary, even one week without it, spurred a panic that I might as well be dead.” Despair at the impossibility of her task—“I knew I couldn’t replicate my whole life in language”—gave way to a new sort of self-transcription once she had a son: “In the diary I recorded only facts. Minutes of nursing, ounces of milk, hours of sleep.” Maternity asked her to surrender the project of recording her life comprehensively: “He needed me more than I needed to write about him.”

At the emotional core of Manguso’s book is an exploration of how motherhood changes her relationship to writing, memory, and time itself. “I used to exist against the continuity of time,” she writes. “Then I became the baby’s continuity, a background of ongoing time for him to live against.” And her book is a formal enactment of this process, presenting a self that cedes particularity and centrality in order to become a backdrop for larger questions: How do we find meaning in our experiences and hold them in memory? How do we reckon with the fact that we’ll all eventually die and be forgotten? For Manguso, becoming a mother means she no longer feels her hours are always full of significant observations waiting to be extracted—“Nursing an infant creates so much lost, empty time”—or preserved in writing: “Then I came to understand that the forgotten moments are the price of continued participation in life.”