Every August this column, as a courtesy to readers and a service to Literature, draws a veil over the world of politics and recommends a novel with which to while away the waning hours of summer. This year's selection is Scott Turow's ''Presumed Innocent.''

Turow will not soon be forgiven for his unspeakable faux pas of writing a novel that is a stunning commercial as well as artistic success. It is published by Farrar, Straus & Giroux, which is known as a ''literary house.'' This has agitated some critics who seem eager to disparage the public by questioning the quality of any work that finds a mass market. It is, they suggest, tacky for a ''literary house'' to publish a book that is only a ''courtroom thriller.''

Actually, Turow's novel is not merely a thriller, although thrilling it certainly is (and steamy and grisly). It is not merely about a murder trial any more than ''Macbeth'' is merely about Scottish politics. Turow gives a shattering depiction of what it feels like to be in the skin of someone falsely accused of a terrible crime. It is the story about the moral vertigo that strikes when one's sense of safety, social standing and moral worth are suddenly and unjustly overturned by institutions of justice.

Criminal prosecution is a minuet of tamed brutality, stylized and decorous but irreducibly brutal nonetheless. Turow's protagonist is a prosecutor who when younger ''could feel the fear, the hot frustration, the haunted separateness'' of those he prosecuted. Now nearly 40, he has become ''a bureaucrat of good and evil,'' aware that ''the business of accusing, judging, punishing has gone on always; it is one of the great wheels turning beneath everything we do.'' Suddenly he is indicted, and the ground opens beneath his feet.

Transformed by an act of a grand jury from a pillar of the community to a pariah, he is seized by fatalism, a sense that life is not reason or order, merely experience. He feels an adhesive dread, a sudden acquaintance with the wilder elements and darker side of mankind.

Imagine being arraigned -- being called a murderer in public -- while hundreds of fascinated eyes are fastened on your facial reaction. Imagine, as Turow does, the cyclonic impact of panic, like groping in the dark for a light switch you are not sure you will ever find.

Pity for others requires, Aristotle said, believing that what afflicted them could afflict you. Turow makes you believe. You will pity his protagonist caught in the toils of the law, and the law will seem terrifying.

Therein lies the novel's emotional wallop and moral message. It teaches, by that terror, how much our sense of life's livableness depends on faith in the criminal-justice system -- faith that justice has been systematized by social arrangements.

Our emotional equilibrium depends more than we normally know on the sense that there is a moral economy in the world, that good is rewarded and evil is punished. We want life to unravel for the criminal, as it did for Macbeth -- but not for the innocent, least of all at the hands of the law. Otherwise, life is a tale told by an idiot.

In other ages, people believed that intervening gods, or God, allocated justice, in this or another world. The waning of that faith has coincided with the rise of law, and lawyers, to a great and stately jurisdiction. They are custodians of the arrangements that keep chaos at bay. Through fissures in that inevitably imperfect system, we glimpse the moral void that deranged Macbeth after he murdered.

Turow alarmingly conveys how many and wide are the fissures through which proof, truth and justice can leak away. No matter how refined the procedures for unraveling the tangle of human motives, a trial is less akin to the tidiness of mathematics than to the tentative gropings of pre-modern medicine.

Turow, a former prosecutor, looks unblinkingly at the harshness that sustains civility. (He writes four paragraphs on prison life that will turn your hair white.) Turow knows the arcana of police procedure and the intricacies of litigation. Judge Learned Hand once said that few things so filled him with fear as the thought of being the defendant in a trial by jury. You will understand why when you read Turow's meticulous creation of a murder trial.

If you do not read it, you will be left out of conversations. There already are half-a-million copies in print. (Paperback rights just sold for $3 million, a record for a first novel.) But do not start the novel on a night when you need your sleep. A sophisticated editor at another ''literary'' publishing house reports that ''Presumed Innocent'' caused him to suspend (for his own benefit) his rule against reading at the dinner table. You have been warned.