In the breakneck world of book reviewing, Ian McEwan's latest novel, Saturday, which was released in March, is already a hoary chestnut from publishing's yesteryear. Because of this sad fact, everyone else has already done a proper review. Instead, let us examine this paragraph-on page 128 in the hardcover edition- from which we may extrapolate a few important truths about this troublesome and troubling novel.

Saturday is a departure from McEwan's milieu in several ways, not least of which is the book's present-tense nature-in terms of both grammar and content. It's a novel about post-9/11 consciousness, and hence, an impossible thing, a reduction of the irreducible. The writing shines when the author dives into the mental stream of Saturday's protagonist and discovers-as in this passage below-that science and poetry, competing methods for understanding the world, are as interdependent as fundamentalism and secularity.

1 - You needn't be a brain surgeon to understand the significance of McEwan's dismissal of the desire to "think biblically." All through the book, protagonist Henry Perowne (who is a brain surgeon, as it happens) rails against the unreason of religion-as well as the unreason of art, particularly poems and novels. To him, there's no difference between the biblical thinking that casts all animals as "edible automata" and the thinking that impels both Islamic terrorism and the "powerful Imperium" that has declared war on it. It's all the opposite of reason. Still, his daughter is coming home, he has a fish stew to prepare, and the only thing blocking his way is a phalanx of Iraq war protestors.

2 - The "growing complication" of this "expanding circle" is the understanding that even if you don't feel you deserve what you have, you're likely to be called upon to defend it, because the world is full of people who believe you deserve even less. The book's great irony is that moral sympathy is supposed to be widening, when in fact the fractiousness of the world demands more intense self-interest than ever.

3 - From people to foxes to mice to fish. In the rhetorical logic of McEwan's reverse incrementum, the life forms get lower and lower, but the doctor's anxiety at having to concern himself with the well being of each intensifies. He knows there's no difference between killing the lobster and merely ordering it, but the comfort of not having to do the killing is a buffer that seems to be eroding.

4 - But Perowne's fierce pragmatism, and sometimes comical fealty to biology, conflicts with his deep emotional attachment to his family and, more importantly, his niggling shame at the opulence of their posh home in the middle of London and all the rewards that attend his accomplishments. It doesn't stop him from owning a Mercedes, but it does keep him from enjoying it. Of course, when he talks about being selective with one's mercies, he's also talking about being selective with one's guilt. After all, you can't miss the word "domination" in there with the more gentle "success."

5 - This passage distills the novel's central theme: the inner conflict that arises in a privileged man who can't shake his awareness that the imbalance of privilege, in all its forms, is the root of every problem facing the world today. The idea that you have to choose what you're going to care about seems obvious, but in its best moments, Saturday makes it clear that the selection of your selective mercies, whether you're worrying about the pain felt by the fish you're about to eat, or the unbalanced man who threatens your family, is an immensely complex challenge-even when the threat in question is close at hand. "What you don't see" is simply another way of saying "what you can't bear to look at." And the peace won't last long.