a physical law of nature whose operations cannot be demonstrated by
mathematical proof. Moreover, we know that the same conditions which cause
a high birth-rate may cause a low death-rate. In the case of the first
settlers in a new country the death-rate is low because the diseases of
civilisation are absent and the settlers are usually young, whereas the
birth-rate is high. If fifty young married couples settle on the virgin
soil of a new country it is probable that for many years an enormous
birth-rate, of over 100, will coexist with a low death-rate.

In reality a high birth-rate may coexist with a low death-rate, or with a
high death-rate. For example, there is a difference between natural and
artificial poverty, the first being brought about by God, or, if any reader
prefers to have it so, by Nature, and the second being made by man. Under
conditions of natural poverty small groups of people in an open country are
surrounded by land not yet cultivated: whereas artificial poverty means
a population overcrowded and underfed, living in dark tenements or in
back-to-back houses, breathing foul air in ill-ventilated rooms seldom lit
by the sun, working long hours in gas-lit workshops for a sweated wage,
buying the cheapest food in the dearest market, and drugged by bad liquor.
In either case their existence is threatened, although for very different
reasons, and the birth-rate rises; but under conditions of natural poverty
the death-rate is low, whereas in slums the death-rate is high.


Section 3. THE LAW OF DECLINE

It would appear, then, that under conditions of hardship the birth-rate
tends to rise, and that in circumstances of ease the birth-rate tends to
fall. If the existence of the inhabitants in a closed country is threatened
by scarcity, the birth-rate tends to rise. For example, "In some of the