emoved from any state of affairs we can really think
of or plan for, that it cannot enter into our reckoning, ideal or
practical? Every ideal takes certain facts of human life for granted
whilst it tries to improve others. All ideal states, Plato's as well as
others, assume certain facts about human nature and human society. These
facts may and do vary. The Greek city state assumed that a state must be
small, if it was to have the intensive life they demanded. The Roman
Empire was a denial of the anarchy to which the Greek ideal had led, but
it lost in intensity what it gained in extent. All political ideals
assume a certain sociological background on which the state is based and
from which spring the problems which the state is intended to solve. As
this sociological background varies from time to time, _the_ State, the
purpose which men set before themselves in political organization, will
vary also. The Greek city state and the mediaeval state were not
different approximations to the same ideal. They were the expressions of
different ideals. They rested on different assumptions, e.g. as to the
place of authority in society. With the disappearance at the Reformation
of one of the great assumptions on which the mediaeval state had been
based, a new theory of the state was inevitable. The national state of
the seventeenth century was something new in history, and Hobbes differs
from Aristotle, not because Hobbes is perverse and Aristotle right,
though Hobbes often is perverse, but because the political problems
which Hobbes and Aristotle had to face were not the same.

Two great historical facts at the end of the eighteenth century, the
French Revolution and the Industrial Revolution, profoundly modified the
basis of political organization. The modern state in consequence differs
in many important respects from any that have preceded it. It does not
rest on the common acceptance of authority, either religious, as did the
mediaeval state, or personal, as did the seventeenth-century state.
Unlike the Greek city state, it is large. Its administration is
concerned with millions who cannot be in personal relations to one
another, or share the same intensive life.

With the nineteenth century, then, a new chapter in the development of
political theory begins as the peculiar problems of the modern state
develop. Professor Dicey, in his _Law and Opinion in England_, has
divided the century into two periods of political thought-