Western society, indeed the whole community of mankind, is built up of these smaller units, the family and the nation, with their various intermediate groupings, but the historical process has by no means conformed at all exactly to this logical order. Society has not been made in orderly fashion by forming families and then combining families to make hundreds, and hundreds to make counties, and counties nations, and so on to the whole. A German god might have done this, but the way of nature and history was less perfect. The minor forms of human association have been taking shape, being altered and on the whole improved, throughout the process. At one point, of high importance for our argument, a larger form of association was achieved before the necessary constituent elements were articulated. This was the Greco-Roman world encircling the Mediterranean and completed in the Roman Empire of the second century A.D. It was the nucleus from which the Western world of modern civilization has been developed; yet it was there, settled in its main outlines, before the national units which it required for internal harmony and cohesion had taken any definite shape. It is to the difficulties of their growth and mutual adjustment that we owe most of the conflicts of modern history. We shall in this book go back first to a still earlier stage, a stage of pre-history, to a time when no one, not gifted with superhuman insight and prescience, could have foreseen the course which human civilization would pursue. All over the world, for tens of thousands of years, a culture persisted, associated with stone implements, and marked by a similarity which is often extremely striking, in races and tribes widely severed by distance and climatic conditions. The raw material of the human product in science, art, and invention was alike in texture although often exuberant in detail and imagination. But it had not yet the unity of an organic whole, knit by a common purpose and conscious of itself. To gain the cohesion of large numbers of men by whom wealth could be created and sufficient leisure and independence secured for an intellectual life, not dictated by the necessities of existence, a special concurrence of favourable physical conditions was required. The rich and secluded river-basins of many parts of the world provided this, and in consequence we find similar large communities arising at the end of the Stone Age in such places as China, Peru, Mexico, and above all in Mesopotamia and Egypt. The last named derived their special importance for the sequel from their proximity to the Mediterranean, which was to act as the great meeting-place and training-school for adventurous spirits and inquiring minds. From the busy intercourse of these land-locked waters arose the civilization called Minoan, or Aegean, centring in Crete, itself to be surpassed by the trading activity of the Phoenicians and the art and science of the Greeks.