Rachel Arndt’s brilliant debut collection, Beyond Measure, explores the idea of “the quantified self," the movement which purports to grant “self-knowledge through numbers.” Overwriting any sentimentalized notion of a unique and irreducible “I,” the self as the sum of private thoughts, Arndt’s “I” is instead an assemblage of data: sleep stats, Airbnb ratings and Tinder likes, pounds weighed and sweat leaked, to-do lists and domestic routines that function like algorithms. This “I” is the circuitry of feedback loops, the precise circling currents of inputs and outputs, the “I” as digital accumulation. In the opening essay, as she attempts to cure her narcolepsy, Arndt writes: “In the sleep lab I let myself become an object . . .