Published last year, Jonathan Crary’s 24/7: Late Capitalism and the Ends of Sleep begins with the effect of digital culture on our sense of time. A world that is always “on”—the irony of “sleep” mode is that it avoids turning off a device—entices or requires humans to be the same. Gradually, we comply: we get less and less rest every night, we rise to check phones or tablets in the wee hours, we pretend work is leisure as we run the hamster wheel of social-media clicks. For Crary, a professor of art history, the life of digital timelessness manifests the most basic and inexorable drive of capitalism, which would shrink whatever is not producing or consuming. Sleep occupies that vanishing margin. Sleep does not want to be productive. “Sleep,” Crary writes, “poses the idea of a human need and interval of time that cannot be colonized and harnessed to a massive engine of profitability.”Crary’s book therefore looks back seriously to a premodern vision of the quotidian, based on repetitive cycles of rest and rising—those spirals that Scheherazade wove into art. But this is not reactionary. Crary wants to reset our clocks, not turn them back. His most valuable insight is that the sheer fact of sleep can be a deliberate choice—a political choice. It could be a mode of resistance.