n interesting study could be made of the fertilizing effect of error in the intellectual world. What a revolution has been caused in historical studies by the enormous errors of those misguided but prolific Germans, Karl Marx, Max Weber, Werner Sombart! The importance of these men is that they obliged scholars to ask new questions: the fact that their own answers were erroneous is a secondary matter. Immediate falsities were soon exposed; ultimately a whole new science was born and more scrupulous thinkers gave exacter answers. Indirectly the new science and the exacter answers owe their existence to the first challenge. The errors of Werner Sombart were certainly heroic. Himself an economist, not a historian, erudite indeed but careless of evidence, he was suddenly inspired by Max Weber's thesis about the relation of the Protestant ethic to capitalism to offer an alternative answer. Why, in the 16th century, had the center of economic power shifted from Southern to Northern Europe, from the Mediterranean to Antwerp, London, and Amsterdam? The discovery of America and the East Indies is no answer-is Hamburg really nearer to the Far East than Venice? Some other explanation is required. Weber had supplied one ideological explanation: Protestantism had created the capitalism of the North. In search of another, Sombart hovered briefly over a desperately insufficient understanding of history, and then, seeing it, or thinking he saw it, pounced. In 1492 the Jews had been expelled from Spain, in 1495 from Portugal, and later from some Italian cities. Whither had they gone? Some few had gone to Northern Europe. What need of further argument? The thesis is proved: "Modern capitalism is nothing more nor less than an expression of the Jewish spirit"; it only needs to be illustrated. Sombart's book The Jews and Modern Capitalism, which appeared in Leipzig in 1911, is the illustration of it, rich, suggestive, intellectually irresponsible, and in its political consequences ultimately disastrous. Himself a Gentile, an admirer of the Jews, he became involuntarily a Founding Father of anti-Semitism.