You may know Joseph Wright's painting, Arkwright's Cotton Mills by Night. Into a dark, almost rudimentary moonlit landscape the artist has inserted, lower left centre, an incongruous squat five-storey building, its windows all illuminated. The point of the painting, Jonathan Crary tells us in 24/7, isn't just about industrialisation: it's about the erosion of all distinction between day and night. The workers in the mills were organised into two 12‑hour shifts. The mills never stopped.

The same thing is happening now, he argues, but with a twist. Today we are willing connivers in our own sleeplessness, as we find ourselves continually diverted and invited to consume at any time of day or night. Meanwhile, military scientists are researching the brain of the white-crowned sparrow, to find out how, during migration, it manages to stay awake for seven days on the trot without sleeping. The idea is to make it possible for soldiers to do the same. As Crary points out, "as history has shown, war-related innovations are inevitably assimilated into a broader social sphere, and the sleepless soldier would be the forerunner of the sleepless worker or consumer".

This short, bracing polemic is very timely and important, leading one to marvel anew at the ways in which neoliberalism manages to be an affront to everything that is decent in humanity. Not enough attention is paid to something that occupies a third of our lives – or, nowadays, more like a quarter (long ago, we used to get 10 hours of sleep a night; in modern America, the average is approaching six). You may recall the fuss made when spikes were erected in a building's exterior alcove to prevent homeless people from sleeping there; but designs of benches specifically intended to prevent anyone lying on them have been around for some time now (since, coincidentally or not, the rise of neoliberalism).

Crary is a professor of modern art and theory, so you are going to have to brace yourself for a certain amount of rhetoric: the round-the-clock world's "peremptory reductiveness celebrates a hallucination of presence, of an unalterable permanence composed of incessant, frictionless operations" etc. The usual suspects – Deleuze and Guattari, Walter Benjamin, Foucault – crop up regularly.

And I struggle to see what Blade Runner, and the Philip K Dick novel that inspired it, or Chris Marker's La Jetée, or Psycho, have to do with his thesis. There's a moment in La Jetée when we are told that "the camp police spied even on dreams", and Crary reminds us of this, but it's all a bit tenuous. You might wonder what he's doing, in chapter 3 (of only four), inveighing against television so much, but he ends with a masterly description of the feeling you get when you switch the TV off: "It is an instant of disorientation when one's immediate surroundings … seem both vague and oppressive in their time-worn materiality, their heaviness, their vulnerability to dilapidation, but also their inflexible resistance to being clicked away in an instant." While once this feeling would only have arisen in a single room, it can now occur anywhere, as our screens are, in effect, prostheses. (It is, on a personal note, nice to have an explanation for the depression and faint disgust I feel whenever I see a television in the kitchen of a family home.)

But any faults this book has are convincingly outweighed by the things it says that are good and true. It cuts through a lot of the starry-eyed nonsense people talk about the empowering nature of new technologies and keeps in mind the whole time that, as far as late capitalism is concerned, we are nothing more than ultimately disposable units for keeping economies running. (And disposable earlier rather than later if we are, like huge numbers of people across the world, incapable of any significant economic productivity.) Read this, and ponder its implications. I would even venture to suggest you sleep on it.

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