most worth conciliating. Nor have we yet succeeded in giving to the
average citizen so elevated a conception of the purpose for which the
State exists that he can think of national policy as something different
from national selfishness. It is easier to criticise the enthusiasts who
urged medieval nations to undertake "some work of noble note," remote
from daily routine, than it is to discover and to preach a nobler
enterprise on behalf of a less visionary ideal. It helps us to
understand, though it does not compel us to accept, the medieval theory,
when we find modern poets and preachers glorifying war as a school of
patriotism or of national character.

Wars of conquest were less frequent in the Middle Ages than we might
expect, and were usually waged on a small scale. Their comparative
infrequency, in an age of militarism, must be explained by reference
both to current morality and to economic conditions. For an attack upon
a Christian power it was necessary that some just cause should be
alleged. Public opinion, educated by the Church to regard Western
Christendom as a single commonwealth, demanded that some respect should
be shown to the ordinary moral code, even in international relations.
Furthermore the medieval state, loosely knit together and bristling with
isolated fortresses, showed in defeat the tenacious vitality of the
lower organisms, and could not be entirely reduced without an
expenditure, on the invader's part, which the methods of medieval
state-finance were powerless to meet. Edward I failed to conquer the
petty kingdom of Scotland; and the French provinces which were ceded to
Edward III escaped from his grasp in a few years. The profitable wars
were border wars, waged against the disunited tribes of Eastern Europe,
or the decadent Moslem states of the Mediterranean. And such wars were
of common occurrence, sometimes undertaken by the nationalities most
favourably situated for the purpose, sometimes by self-expatriated