Here, in a novel deeply concerned with Time, there is virtually no past
tense. Present-tense narration is now taken for granted by many fiction
readers because everything they read, from internet news to texting, is
in the present tense, but at this great length it can be hard going.
Past-tense narration easily implies previous times and extends into the
misty reaches of the subjunctive, the conditional, the future; but the
pretence of a continuous eyewitness account admits little relativity of
times, little connection between events. The present tense is a
narrowbeam flashlight in the dark, limiting the view to the next step -
now, now, now. No past, no future. The world of the infant, of the
animal, perhaps of the immortal.
-- Ursula K Le Guin
Review of The Bone Clocks by David Mitchell.
The Guardian (Sep. 2, 2014)
http://www.theguardian.com/books/2014/sep/02/the-bone-clocks-david-mitchell-review-novel