Bertrand Arthur William Russell , 3rd Earl Russell , OM , FRS , ( 18 May 1872 â `` 2 February 1970 ) , was one of the world 's best-known intellectuals . He was a philosopher , logician , and mathematician . Bertrand Arthur William Russell , 3rd Earl Russell , OM , FRS ( 18 May 1872 â `` 2 February 1970 ) , was a British philosopher , logician , mathematician , historian , and social critic .