What distinguishes [Endo from the modern Japanese masters is his] deceptively simple blend of unimpeded narrative and matter-of-fact style with fidelity to Japanese behavior and psychology.

It would be easy to attribute Mr. Endo's accessibility to the fact that he is a Roman Catholic and therefore himself an "exotic" in Japan. He has been called "the Japanese Graham Greene."… [But] the label is unhelpful. What interests Mr. Endo—to the point of obsession—are the concerns of both the sacred and the secular realms: moral choice, moral responsibility….

"When I Whistle" is a seductively readable—and painful—account of these issues. Mr. Endo skillfully interviews two sets of characters from two periods of Japanese history: the militarism of the 1930's and the war years, and the brash opportunism of the early 1970's, when the country was impatient with past pieties….

What both unites and distinguishes these two otherwise disparate stories is the tenuous—in the "new" Japan, almost vanishing—filial bond between [the protagonist Ozu, a humdrum clerk, and his son, a surgeon], the great body of unacknowledged assumptions and loyalties that divides them….

One of the striking features of the novel, as of the author's previous works, is his attention to particular detail…. "When I Whistle" is full of authentic touches, the fruit of his experience, without any display of specialized learning. This informed realism effectively underpins the conflict between the old order and the new: Ozu is ignorant but right, Eiichi is sophisticated but wrong.

Mr. Endo writes about this conflict in Japanese terms because he is Japanese. But the story can just as easily be understood universally, for the author has decisively broken away from many of the features that have both made and marred the Japanese tradition. He generally avoids pregnant imagery for example, when it occasionally appears … it seems an intrusion, for all its apposite grace. The impression persists throughout "When I Whistle" that Mr. Endo—though he denies that "the truest poetry is the most feigning"—tells the truth as he sees it.