It may be that Hans Bethe, whom Bernstein describes as polite and cooperative, is simply not as self-revelatory as some other great innovators. Or it may be that Bernstein had a slightly different agenda in mind in this brief biography (originally published in The New Yorker). Whatever the reason, the reader comes away from the book with a sense of unfulfillment. Bethe emerges as the brilliant scientist we expect him to be; we learn of his major accomplishments through the years at Los Alamos as head of the theoretical group under Oppenheimer, and now, as Cornell professor emeritus and an outspoken authority on energy. But the book then becomes a platform for his (and Bernstein's) advocacy of nuclear power and for considered opinions on the potential of coal, gas, oil, and alternative energy sources to meet the country's future needs. One anecdote serves as a useful bridge: Bethe describes life in Germany during the post-WW I years of brutal inflation and severe food and coal shortages. Twice a week he would bicycle to the university to collect his father's salary which was immediately spent on food and other essentials in anticipation of another round of devaluation. Thus Bethe's sensitivity to society's needs and specifically to the energy crisis. He argues persuasively for the use of nuclear power (emphasizing the need for more efficient reactor designs) and points out the need to recycle fuel, build in better controls, and train more sophisticated operators. He believes that coal will be of major importance in the future, and will bring a renaissance of the railroads. And while he would encourage research on wind and solar power, he sees no way that they can realistically supply more than a fraction of the energy demand. All this makes for an intelligent if somewhat dry text, reinforcing Bernstein's portrait of Bethe as a thorough analyst who painstakingly weighs all the data and then produces sensitive dicta. But the lesson would have benefited from a little leavening.