"I remembered at this time the brilliant critical analysis of the German Social Democracy which Rosa Luxemburg had written in gaol in 1914, after her arrest for anti-militarist activity. The pamphlet had been signed by the pseudonym "Junius" and it was a confirmation of prophecies I had heard her make at a German Congress in Hanover many years before when she had engaged in a brilliant polemical duel with the German Revisionist, Edward Bernstein. Even then she had foreseen the development of that pernicious opportunism which was to result in the tragedies of the post-war years."