Gavin Langmuir distinguishes between anti-Judaism and antisemitism. For him, anti-Judaism is hostility toward Jews (where by "Jews" we mean anyone perceived as Jewish in a given context) as practitioners of an alien religion of which one disapproves. Anti-Judaism as such needn't be irrational, and it is essentially no different from, e.g., the antagonism between pagans and Christians in the Roman Empire, the wars between Catholics and Protestants, or any number of other examples of intergroup hostility throughout history. By antisemitism Langmuir means a hostility toward Jews based on "irrational fantasies," that is, beliefs about Jews that have no basis in fact. Historic instances of antisemitism thus defined would include the Medieval blood libels and charges of host desecration and well-poisoning, as well as the more modern conspiracy theories. This conceptual distinction leads Langmuir to conclude that antisemitism in Western Christendom appeared in the 12th century, with the first known accusation of ritual murder in the case of William of Norwich, and with Peter the Venerable's published conclusion that Jews uniquely lack the capacity for rational thought which distinguishes human beings from animals. Langmuir uses his definitions to argue the relative historic uniqueness of antisemitism. This is reasonable as far as it goes: Langmuir's definition of antisemitism is unquestionably useful for thinking about the differences in the hostilities toward Jews throughout time and space. But as with any definition, it ought not be treated as an absolute. Its main shortcoming is that it fails to capture a common kind of hostility, which does not necessarily contain "irrational fantasies" at the level of empirical reality, but which implicitly creates one rule for the Jews and another for "everyone else" (by which we mean other religious or ethnic/national groups, depending on the context). Langmuir as a historian is concerned with positive empirical claims, or "truth," to the neglect of normative claims, or "justice." This is quite understandable because the Principle of Equality as a basis for political organization is a recent invention, while Langmuir deals primarily with periods where treating different groups differently was the accepted norm. But if we are concerned with the phenomenon of antisemitism in our Age of Democracy it would perhaps be more useful and instructive to take the point of view of "justice" in thinking about how to define what we wish to study.
This book is for those who already have some knowledge of the history of antisemitism, or the history of European Jewry. For those who know little beyond the commonplaces about "racist Nazis" the best single volume introduction is Malcolm Hay's "Europe and the Jews."
