ibbon tells us, to nine pounds
sterling on every freeman? What was it, then, which occasioned the
depopulation and weakness? This is what it behoves us to know--this it
is which ancient history has left unknown.

It is here that the vast step in the philosophy of history made from
ancient to modern times is apparent. From a few detached hints and
insulated facts, left by the ancient annalists, apparently ignorant of
their value, and careless of their preservation, modern industry,
guided by the light of philosophy, has reared up the true solution of
the difficulty, and revealed the real causes, hidden from the ordinary
gaze, which, even in the midst of its greatest prosperity, gradually,
but certainly, undermined the strength of the empire. Michelet, in his
_Gaule sous les Romains_, a most able and interesting work--Thierry,
in his _Domination Romaine en Gaule_, and his _Histoire des Rois
Merovingians_--Sismondi, in the three first volumes of his _Histoire
des Francais_--and Guizot, in his _Civilisation Europeenne_, and the
first volumes of his _Essais sur l'Histoire de France_--have applied
their great powers to this most interesting subject. It may safely be
affirmed, that they have got to the bottom of the subject, and lifted
up the veil from one of the darkest, and yet most momentous, changes
in the history of mankind. Guizot gives the following account of the
principal causes which silently undermined the strength of the empire,
flowing from the peculiar organization of ancient society:--

"When Rome extended, what did it do? Follow its history, and you
will find that it was everlastingly engaged in conquering or
founding cities. It was with cities that it fought--with cities
that it contracted--into cities that it sent colonies. The
history of the conquest of the world by Rome, is nothing but the
history of the conquest and foundation of a great number of
cities. In the East, the expansion of the Roman power assumed,
from the very outset, a somewhat dissimilar character; the
population was differently distributed from the West, and much
less concentrated in cities; but in the European world, the
foundation or conquest of towns was the uniform result of Roman
conquest. In Gaul and Spain, in Italy, it was constantly towns
which opposed the barrier to Roman domination, and towns which
were founded or garrisoned by the legions, or strengthened by