Naming and describing "the centrifugal forces which make it difficult if not impossible to unify Europe," Nathan Isaacs, Professor of Business Law, yesterday gave the first of two lectures in History 1 on post-war problems in Europe. Professor Isaacs was introduced by Roger B. Merriman '96, Gurney Professor of History, as "a profound student and authority on international affairs."

According to Professor Isaacs, the failure of the old bases of unity is largely to blame for the present European situation. The Catholic Church was supplanted as a unifying force in the Middle Ages by the birth of international law. This was supplemented in the nineteenth century by the theory of balance of power and by the congress system. "But these influences have been entirely swept away in the twentieth century," he said.

Nationalistic propaganda, which has become much more effective in recent years than it has in the past, has also done much to keep unity from Europe. Parete, said Professor Isaacs, explained how men's actions in recent times have resulted too frequently from impulses and not from logical reasoning.

Ideologics and personalities, defects of treaties and plans made at the end of the last war, failure of democratic constitutions, and the present depression all are "centrifugal forces" which have prevented European unity, Professor Isaacs said. On Friday he will discus the centripetal forces which have tended toward unity.