Subtle Is the Lord

Anyone studying Einstein (even cursorily) will quickly encounter Abraham Pais's classic. Published in 1982, it has stood like a monument, influencing every study of Einstein since. Pais knew Einstein well and sprinkles his book with invaluable personal anecdotes and first-hand information. Because it focuses on Einstein's science, it can be a little intimidating, but it is organized well and readers can bounce around the book easily, focusing on what they find most appealing. 

There are almost as many biographies of Einstein as there are of Lincoln! But Pais, who knew Einstein well, has produced the best, most reliable account of the great man’s life and work. If Einstein had died at the end of 1905 he would have been considered, without question, the greatest physicist of his time; but a decade later his work on general relativity placed him alongside Newton as one of the greatest of all time.