II. Groups in Contact 32 III. Intolerance 45 IV. American History, a Development of Groups 56 V. The World War and Its Aftermath 67 VI. The Ku Klux Klan and Other Group Reactions 74 VII. Anti-Semitism 85 VIII. The Retort to Anti-Semitism 96 IX. The Future of the American Mind 111 INTRODUCTION A STATEMENT OF THE PROBLEM The existence of an anti-Semitic movement in the United States of America since the World War is a paradox that attracts attention at once. The most ancient and most pervasive form of intolerance is now at home in a nation founded by revolution and dedicated to the principles of freedom and tolerance. How can such a movement exist in such a nation? The apparent contradiction leads us at once into the many contradictions of the psychology of large groups of human beings, which both parallels and contradicts the simpler psychology of their constituent individuals. This is a leading question, to answer which we must go as deeply as we can into the mind of the group, into the relation of groups to the smaller groups of which they are composed and of those smaller groups to each other, into the genesis and implications of tolerance and intolerance. This theoretical study completed, we shall then have to verify the principles there worked out by application to the difficult and crucial problem of the present study. If a theory of group and sub-group can explain the existence and the development of anti-Semitism in America, it will have solved a problem of exceptional complexity and significance, one central to the whole field. This will involve a study of the mind of the American people, in brief outline, with its various movements of intolerance in their bearing on the present one. It will also necessitate a slight study of the various anti-Semitic examples, historic and contemporary, from which the American movement derives in part. It will conclude with a consideration of the future of the American people as a united group, taking into view the tendencies of the sub-groups within the bounds of their common nation, or over-group.