the church and the rise of modern languages and literatures have
been centrifugal forces, they have been outweighed by the advent of new
influences tending to bind all peoples together. The place of a single
church is taken by a common point of view, the scientific; the place of
Latin as a medium of learning has been taken by English, French, and
German, each one more widely known to those to whom it is not native
now than ever was Latin in the earlier centuries. The fruits of
discovery are common to all nations, who now live under similar
conditions, reading the same books and (under different names) the same
newspapers, doing the same {452} business and enjoying the same
luxuries in the same manner. Even in matters of government we are
visibly approaching the perhaps distant but apparently certain goal of
a single world-state.

[Sidenote: Changes in population]

In estimating the economic and cultural conditions of the sixteenth
century it is therefore desirable to treat Western Europe as a whole.
One of the marked differences between all countries then and now is in
population. No simple law has been discovered as to the causes of the
fluctuations in the numbers of the people within a given territory.
This varies with the wealth of the territory, but not in direct ratio
to it; for it can be shown that the wealth of Europe in the last four
hundred years has increased vastly more than its population. Nor can
it be discovered to vary directly in proportion to the combined amount
and distribution of wealth, for in sixteenth-century England while the
number of the people was increasing wealth was being concentrated in
fewer hands almost as fast as it was being created. It is obvious that
sanitation and transportation have a good deal to do with the
population of certain areas. The largest cities of our own times could
not have existed in the Middle Ages, for they could not have been
provisioned, nor have been kept endurably healthy without elaborate
aqueducts and drains.

Other more obscure factors enter in to complicate the problems of
population. Some nations, like Spain in the sixteenth and Ireland in
the nineteenth century, have lost immensely through emigration. The
cause of this was doubtless not that the nation in question was growing
absolutely poorer, but that the increase of wealth or in accessibility
to richer lands made it relatively poorer. It is obvious again that
great visitations like pestile