Ferdinand Lassalle, an admirer and onetime friend of Karl Marx, was one of the most colorful and romantic figures in nineteenth-century history, an energetic and self-assertive political activist whose ardent radical convictions inspired him to powerful oratory and to ambitious and reckless deeds. He was an idealist with a strong sense of justice and inordinately high hopes for the victory of democracy and socialism in his own time; but he was also a master of effective propaganda and a political realist who concentrated on immediate tasks. He first earned public notoriety for his personal campaign on behalf of a woman whom he defended as a representative victim of male prejudice and of an unjust society. He kept himself in the limelight in a series of political trials in which he propagated his ideas by turning his defense into an accusation of his accusers. Meteorlike he emerged from an...