The expansion of Europe and the industrial revolution brought about revolutionary changes in the life of humanity, changes that had no counterpart in the previous history of the human race. The European peasant of 1700 or even of 1800 could have adjusted himself readily to the life of the agricultural communities in the valleys of the Nile or Euphrates in the year 5000 B.C. He would have been completely bewildered and frightened by the life of the farmers of Alberta or Kansas in 1950. A similar metamorphosis has taken place in the lives of other classes of society during the last two centuries. It is true that many of the commercial practices of the present day can be traced back to the earliest periods of recorded history, but while the clerks of King Hammurabi could have quickly adapted themselves to the handling of the commercial and financial problems of Henry VIII, they would have required a good deal of post-graduate training before they could have made the additional and very much briefer transition into the life of the twentieth century.

Radical as have been the changes in the forms and content of civilization since the Italian and English and Spanish and French explorers of the sixteenth century followed the sun westward across the Atlantic, there is no evidence that the process of change is terminating or even slowing down. Indeed, the contrary is true. As the changes of the nineteenth century exceeded those of several millenia, today the changes of a decade are likely to surpass those of the preceding hundred years.