In the case, the singular case, of Franz Kafka, the law of diminishing returns might be applied in an adapted form: the more diminished the text, the richer the return. He was a master of the fragment, and an aphorist every bit as great as Nietzsche or Rochefoucauld. Consider these few examples. “A cage went in search of a bird.” “I feel like a Chinaman going home; but then, I am a Chinaman going home.” “There is a destination but no way there; what we refer to as way is hesitation.” “In your struggle with the world, hold the world’s coat.” And then there is that famous, and famously sly, response he gave to his friend Max Brod who had asked if there was any hope to be had in the world: “Plenty of hope – for God – no end of hope – only not for us.”

In this splendid new selection from Kafka’s fiction – though Kafka’s fiction calls for some other, unique designation – Mark Harman, professor emeritus of German and English at Elizabethtown College in the US, begins with two fragments, Wish to Become an Indian and The Trees, which might be epigraphs written specially by Kafka himself.

These are followed by a more extensive story, The Judgment, composed in a single night in September 1912 and one of the very few of his own works that Kafka found acceptable. Then come two of the longest tales. These are The Transformation, the title Harman prefers, and rightly so, for what is usually known as The Metamorphosis, in which poor Gregor Samsa awakes one morning to find he has been turned overnight into a beetle; and that truly terrifying vision of things to come, In the Penal Colony.

This last story is not as well known as the other two, but it is every bit as powerful, and more appalling in its calm and measured telling. It features an infernal machine that executes miscreants by slowly graving the words of their sentence – surely the mot juste – into their bodies by way of a moving metal stylus. The tone in which the “procedure” is described is the most striking aspect – Harman in his notes tells us that Kurt Tucholsky, one of the first critics to appreciate Kafka’s genius, “had a visceral reaction: ‘I gulped down a faint taste of blood…’” It is a taste that lingers.

After these three tales, the compass narrows steadily and the final two pieces in the collection, Little Fable and A Commentary, are not much more substantial than the two fragments with which it opened.

In Kafka’s work, of course, substance is wholly out of proportion to mere extension. One of his most luminous, witty and terrible aphorisms, written into his diary in March 1922, consists of fewer than a dozen words: “Somewhere help is waiting and the beaters are driving me there.”

It is an image Kafka returned to. In a letter to his long-suffering lover Felice Bauer, he wrote that when he was a child his mother in her behaviour towards him “unconsciously played the part of a beater during a hunt”. He saw himself as always harried, always on the run, ducking and dodging the ineluctable death penalty. Writing later in 1922, this time to Max Brod, he bows to the inevitable, having been diagnosed with tuberculosis: “What I have play-acted is really going to happen. I have not bought myself off by my writing. I died my whole life long and now I will really die.”

In utterances such as this – indeed, in every one of his published utterances – we see the truth of the declaration he made to Bauer: “I have no literary interests; I am made of literature; I am nothing else and cannot be anything else.” Even in the extremes of anguish he could not write without a stylish flourish or a touch of melancholy humour. Towards the end, he and another lover, Dora Diamant, devised a madcap scheme to emigrate to Palestine where they would both work in a restaurant in Tel Aviv, she as cook and he as a waiter. He related the fantasy to yet one more of his lovers, Milena Jesenská: “If I’m never going to leave my bed, why shouldn’t I go at least as far as Palestine?”

Harman’s long and absorbing introduction is one of the most concise, perceptive and measured accounts of Kafka and his work to have appeared since Reiner Stach’s magnificent three-volume biography, published in Shelley Frisch’s English translation between 2005 and 2016. This year is the centenary of Kafka’s death, and Selected Stories is one of a number of books published to mark the event. The translations are surely definitive – Harman’s grasp of the German language is as comprehensive as was the Czech-born Kafka’s – but the prime value of the book is in the annotation. Every nuance of language is flagged, every cross-reference is followed up, every subtle shade of humour is highlighted. This is academic work as it should be done, in faithful service to the text and to its readers.

• Kafka: Selected Stories, translated and edited by Mark Harman, is published by Harvard University Press (£24.95). To support the Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply