The first thing he does is to cut up the field of historical study into a specifiable number of distinct sections, each called a society. Each society is wholly self-contained. It is for Toynbee a very important question whether Western Christendom is a continuation of Hellenic society or a different society related to it by way of affiliation. The right answer, according to him, is the second.
These are distinctions about how we categorize what we are studying, not intrinsic properties of populations over time.
