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...