Ronald W. Clark's definitive biography of Einstein, the Promethean figure of our age, goes behind the phenomenal intellect to reveal the human side of the legendary absent-minded professor who confidently claimed that space and time were not what they seemed.

Here is the classic portrait of the scientist and the man: the boy growing up in the Swiss Alps, the young man caught in an unhappy first marriage, the passionate pacifist who agonized over making The Bomb, the indifferent Zionist asked to head the Israeli state, the physicist who believed in God.