Since Einstein of all scientists has been revered as gentle, kind, warm, friendly, etc., the adjective in the title seems a bit egregious. Presumably it is meant to indicate that here is a non-technical opus. That it is. Helen Dukas, Einstein's secretary from 1928 until his death in 1955, and Banesh Hoffman, her collaborator on an Einstein biography, have assembled a selection of Einstein letters which span most of the life, and they add a brief running commentary. Many were written to strangers, school-children, fans, college students. As such they confirm the image of the man as a defender of truth, committed to freedom, peace, and justice. They are examples of clear, straightforward expression with occasional flashes of wit, anger, or a stylish aphorism or two--""Nationalism is an infantile sickness. . . it is the measles of the human race."" Many of the letters touch upon Einstein's philosophy of life, on the meaning of religion, being a Jew, or the deplorable state of Germany (called Barbaria). A few are more personal--a letter to Queen Elizabeth of Belgium upon the death of her husband, or letters to friends still in Germany. The correspondence also reveals a penchant for doggerel--not of the kind we need to remember him by. Eventually Princeton will publish it complete. This centenary offering is something of a safe appetizer--sweet and not too filling, with nothing to disturb the well-digested image of the man.