His contemporaries used to say that Lasker used a "psychological" approach to the game, and he sometimes deliberately played inferior moves to confuse opponents. That was, of course, not true. What Lasker did was use a flexible approach that his contemporaries did not appreciate because he was ahead of his time.
In addition to chess, few players today realize that he also made contributions to the development of contract bridge player which he also wrote about. See Chess and Bridge article by Edward Winter HERE. Lasker was also a research mathematician who was known for his contributions to algebra; he was also a philosopher.
Lasker studied mathematics and philosophy at the universities in Berlin, Göttingen and Heidelberg and in 1895 he published two mathematical articles in Nature. He did his doctoral studies at Erlangen during 1900–02 and in 1901 he presented his doctoral thesis titled On Series at Convergence Boundaries; he was awarded his doctorate in mathematics in 1902. Lasker held short-term positions as a mathematics lecturer at Tulane University in New Orleans (1893) and Victoria University in Manchester (1901; Victoria University was one of the "parents" of the current University of Manchester). However, he was unable to secure a longer-term position.
In 1906 Lasker published a booklet titled Struggle in which he attempted to create a general theory of all competitive activities, including chess, business and war. He produced two other books on philosophy, Comprehending the World and The Philosophy of the Unattainable.
In July 1911 at the age of 42 he married Marthe Cohn (née Bamberger), a rich widow who wrote popular stories under the pseudonym "L. Marco". Mrs. Lasker died in Chicago on 18 October, 1942. Also, refer to Laskermania at Chessdotcom for an excellent article by Batgirl.
During World War I, Lasker invested all of his savings in German war bonds and as result of the German defeat, he lost all his money. During the war he wrote a book which claimed that civilization would be in danger if Germany lost the war. In 1933 when Hitler started his campaign against Jews, Lasker and his wife were forced to flee Germany and after a short in stay in England, in 1935 they were invited to live in the USSR by Nikolai Krylenko, the Commissar of Justice and in his other capacity as Sports Minister, was an enthusiastic supporter of chess.
In the USSR, Lasker renounced his German citizenship and received Soviet citizenship and took residence in Moscow where he was given a post at Moscow's Institute for Mathematics and served as trainer of the USSR national team. Stalin's Great Purge started at about the same time the Laskers arrived in the USSR and so in August 1937 they left the Soviet Union and moved to the United States (first Chicago, next New York) in October 1937. The following year Lasker's patron, Krylenko, was purged.
Lasker tried to support himself by giving chess and bridge lectures and exhibitions because he was too old for serious competition. In 1940 he published his last book, The Community of the Future, in which he proposed solutions for serious political problems, including anti-Semitism and unemployment. Lasker died of a kidney infection in New York on January 11, 1941, at the age of 72, as a charity patient at the Mount Sinai Hospital. He was buried in the Beth Olom Cemetery, Queens, New York. Find a Grave The Brooklyn Daily Eagle had a column by Herman Helms devoted to Lasker's passing in the January 16, 1941 edition.
In 1926 Lasker wrote Lehrbuch des Schachspiels, which he re-wrote in English in 1927 as Lasker's Manual of Chess, one of the greatest instructional books ever. The sections on tactics, positional play, and the model games are superb. Lasker disagreed with most opening analysis of his day and largely agreed with the ideas of Steinitz, especially when it came to positional considerations. Lasker believed that every position was unique and that sometimes it called for a move that was in contradiction of accepted principles.
I have in my library a book that I have paid scant attention to, Lasker's Greatest Chess Games (1889-1914) by Fred Reinfeld and Reuben Fine. However, after playing through some of his games recently, I have discovered Lasker, really, for the first time and realized he played some amazing chess.