Book excerpt: Great photographs change the way we see the world; The Ongoing Moment changes the way we look at both. With characteristic perversity – and trademark originality - The Ongoing Moment is Dyer's unique and idiosyncratic history of photography. Seeking to identify their signature styles Dyer looks at the ways that canonical figures such as Alfred Stieglitz, Paul Strand, Walker Evans, Kertesz, Dorothea Lange, Diane Arbus and William Eggleston have photographed the same scenes and objects (benches, hats, hands, roads). In doing so Dyer constructs a narrative in which those photographers – many of whom never met in their lives – constantly come into contact with each other. It is the most ambitious example to date of a form of writing that Dyer has made his own: the non-fiction work of art.