From Mein Kampf:
That is the point when I saw two dangers approaching. Previously, I did not truly understand their names or their importance to the German people’s existence. Their names were Marxism and Jewry.
At the age of seventeen, I had become somewhat acquainted with the word Marxism and I thought Socialism and Social Democracy were identical ideas. Again, the hand of Fate opened my eyes to this unprecedented fraud on the people.
A knowledge of the Jews is the necessary key to grasping the real intentions of Social Democracy. If a person knows these people, the mask of delusion hiding their aims and the meaning of the party falls from his eyes, and the ape-like face of Marxism grins at him.