THOSE who, like the present reviewer, are personally unacquainted with Einstein, will read this book with a shock of surprise. While Dr. Frank‘s sympathies are all with Einstein, the portrait presented to us is not altogether a pleasant one. We see a man developing early into the traditional type of nineteenth-century ‘professor'. He regards himself as free to develop any eccentricity of behaviour, whether those about him like it or not, and to talk shop in season or out of season, a characteristic illustrated (p. 144) by the description of a courtesy visit to a non-mathematical colleague in Berlin, in which, after subjecting his hosts to a forty-minutes discourse on relativity, Einstein left abruptly. This lack of appreciation of the fact that ideas and interests which did not happen to interest him might still be as valuable as those that did may well explain Einstein‘s difficulties in the Berlin Academy, or his failings as a teacher. Always, apparently, ready to lecture on his researches of the moment or to deliver popular discourses, Einstein was not prepared to teach his students systematically what they had need to learn. An attitude of this kind is not incompatible with a deep concern for abstract causes such as pacificism or Zionism, and his lack of human contacts had one good result : it turned Einstein in the early 1920‘s from becoming a political leader of the Zionist movement. But there is another side to the picture : an impulsive kindliness made him only too ready to help refugee scholars after 1933, or to aid by correspondence a student in Prague (p. 331), or to instruct in arithmetic, at her own suggestion, a little girl of ten who lived near him in Princeton (p. 356).