ABSTRACT
We can decide which advantages we wish our present worldwide society to ensure and
which ends we wish it to promote. An understanding of the workings of international
societies in the past helps us to translate our wishes realistically into practice, by showing
us what modifications of our present international society are practicable, what
advantages they might bring and at what price. A realistic understanding is very difficult
to obtain if we remain imprisoned in the conventional legitimacies and half-conscious
assumptions of our own time. We need a broader base of comparison. As the natural
sciences and medicine look for many examples of a phenomenon in order to understand it
well enough to modify it, so history can enable us to distinguish the area of necessity
from the area of choice.