I came into history from a primary concern with mathematics and science. This has been a tremendous help to me as a person and as a historian, although it must be admitted it has served to make my historical interpretations less conventional than may be acceptable of many of my colleagues in the field.

It is this power structure which the Radical Right in the United States has been attacking for years in the belief that they are attacking the Communists.

It is also in theory, conceivable that some universal empire some day might cover the whole globe, leaving no external "barbarians" to serve as invaders.

To know is not too demanding: it merely requires memory and time. But to understand is quite a different matter: it requires intellectual ability and training, a self conscious awareness of what one is doing, experience in techniques of analysis and synthesis, and above all, perspective.

A civilization is complicated, in the first place, because it is dynamic; that is, it is constantly changing in the passage of time, until it has perished.

The basis of social relationships is reciprocity: if you cooperate with others, others will cooperate with you.

Hitler's economic revolution in Germany had reduced financial considerations to a point where they played no role in economic or political decisions