I got this paragraph from his book, What does the underline sentence mean? What is he talking about? "At the Realschule I knew one Jewish boy. In the Jew I saw only a man who was of a different religion, and therefore, on grounds of human tolerance, I was against the idea that he should be attacked. Once, when passing through the inner City, I encountered a phenomenon in a long caftan and black side-locks. My first thought was: Is this a Jew? Is this a German? I bought some anti-Semitic pamphlets. But most of the statements made were superficial and the proofs extraordinarily unscientific. But any indecision was removed by the activities a great movement, called Zionism. Its aim was to assert the national character of Judaism, and the movement was strongly represented in Vienna."