Challenging economic determinism, Dr. Pribram holds that "the prevailing mode of thought is the matrix of all institutions" as well as the source of social conflict. The four main patterns in the Western World--the universalistic, the nominalistic, the intuitional and the dialectical--are seen to have their social expression in, respectively, the Catholic Middle Ages, Western Europe and especially the Anglo-Saxon countries, Germany and Central Europe, and Bolshevik Russia.