The heroine of Ian McEwan’s new novel, The Children Act, is Fiona Maye, a middle-aged London judge who rules on cases involving the welfare of children. Resolving moral dilemmas is her daily work, and she does it with clarity and aplomb. Seemingly every week, she confronts cases like this: A London hospital seeks legal permission to separate Siamese twins whose devout Catholic parents have blocked the operation. If left unseparated, both twins will die. If separated, one will die, but the other will live. Is it right for a judge to authorize the procedure, disregarding the parents’ view that a surgical intervention usurps God’s power to give and take away life?

In another case, Jewish parents clash over whether their daughter should be raised within the strict traditions of an Orthodox sect. The mother wants her child to receive a more secular education that might allow her to work outside the home one day, but the father argues that the women in the community are happy with conventional roles. Is it the place of a judge to decide what sort of upbringing the daughter will have?

Maye’s answer is a qualified yes in both cases, although she recognizes that the correct legal ruling does not always coincide perfectly with the best moral choice. McEwan is keen to emphasize the difficulty of the decisions, and though he makes Fiona sufficiently decisive to do her job, he also relishes her hesitations and doubts about each possible course of action.

These first two cases appear mainly as preamble, summarized without much elaboration. The novel’s primary focus is a third difficult case that shares themes and tensions with the first two. A 17-year-old boy with leukemia is refusing life-saving blood transfusions because, for a Jehovah’s Witness, accepting the blood of another creature violates a fundamental prohibition of his faith. His parents and co-religionists support his willingness to die, but the boy’s doctors want a court order to authorize treatment.

While Maye confidently presides over the public trial, her private life has fallen into disarray. Her husband is an academic who, frustrated by a sexual desert of seven weeks, opts to ignore 35 years of marriage and try an affair with a graduate student. The threat to the marriage is mortal, as Maye’s arch musings on the associations of the student’s name make clear: “Melanie. Not so remote from the name of a fatal form of skin cancer.”

McEwan is not very subtle in savoring the neat inversion of his protagonist’s situation. Fiona reflects on her predicament, “A professional life spent above the affray, advising then judging, loftily commenting in private on the viciousness and absurdity of divorcing couples, and now she was down there with the rest, swimming with the desolate tide.” It’s hardly a revelation that the personal lives of judges are not exempt from the same lust and folly that propel people into courtrooms, but it does provide a potentially compelling structure for a novel exploring the difference between moral dilemmas as abstractions and lived realities.

McEwan seems to have grown enamored with the formal technique of embedding small facsimiles of stories within a larger narrative. In his previous novel, Sweet Tooth, the primary tale was repeatedly interrupted by extended accounts of short stories written by one of the characters, an aspiring young author named Tom Haley. The summaries of various legal cases in The Children Act serve a similar function; the themes in these micro-dramas tempt you to find parallels with the broader enclosing narrative, establishing a play of light between different scales of narrative. They also remind you that any story can be schematized, reduced to a skeletal set of relevant facts and applicable legal principles.

The work of a novelist presumably involves invoking the inner worlds of characters in a way that complicates the austere formulations of moral reasoning. McEwan does gesture toward an irreducible specificity in his protagonist; she hums Bach on her walk to work, buys a frozen dinner after a long day, is fond of her many nieces and nephews. But the legalistic exposition that he uses ultimately reduces her to a figure in an abstract dilemma like those on which she deliberates. Should she leave her husband and endure loneliness or tolerate his dalliance and keep a companion for old age?

The question lacks human urgency because McEwan doesn’t quite succeed at doing more than tallying pros and cons, listing reactions and actions. He seems to behold his characters more than inhabit them, and this creates a sterile distance, a sense of reading a summary of others’ misfortune. Her case just feels like one of many, not fundamentally different than the ones she considers. The story is schematic and contrived rather than palpable and lived.

There’s certainly some evocative writing, particularly on the subject of imminent old age. Fiona looks in her husband’s eyes and sees “a gentle hint of future vacancy.” She appraises him clinically: “Not the full withering, not just yet, but its early promise was shining through, just as one might catch in a certain light a glimpse of the adult in a 10-year-old’s face.” The image has a suggestive symmetry, the older face latent in the younger just as the youthful face anticipates an older incarnation. But he sacrifices specificity of voice for this and other imagery; Fiona’s thoughts and reflections often don’t feel very particular or believable.

The prose also becomes lazy and clichéd at points. Men are described as vanishing into “the smithy of a hot new marriage to forge new offspring,” and the 17-year-old with leukemia is described as a “sweet boy” with a “passion for life.” McEwan novels often have formally dazzling conclusions that recast the meaning of the preceding story. Here, however, the novel ends with unearned sentimentality and cheap contrivance. The only tears likely to be shed are those of the characters in the book.