Although Einstein was the greatest genius of the twentieth century, many of his ground-breaking discoveries were blighted by mistakes, ranging from serious misconceptions in physics to blatant errors in mathematics. For instance, Einstein's first theoretical proof of the famous formula E = mc2 was incomplete and only approximately valid; he struggled with this problem for many years, but he never found a complete proof (better mathematicians did). In this provocative forensic biography, Hans C. Ohanian dissects this and other mistakes and places them in the context of Einstein's turbulent life and times. Einstein was often navigating in a fog of irrational and mystical inspirations, but his profound intuition about physics permitted him to reach his goal despiteand sometimes because ofthe mistakes he made along the way. Einstein's uncanny ability to use his mistakes subconsciously as stepping stones toward his revolutionary theories was one hallmark of his genius.