, be pretty well satisfied as to his
qualifications for setting up theories of his own. We will, therefore,
present them with a few instances of the skill and fairness which he
shows when he undertakes to pull down the theories of other men. The
doctrine of Mr Malthus, that population, if not checked by want,
by vice, by excessive mortality, or by the prudent self-denial of
individuals, would increase in a geometric progression, is, in Mr
Sadler's opinion, at once false and atrocious.

"It may at once be denied," says he, "that human increase proceeds
geometrically; and for this simple but decisive reason, that the
existence of a geometrical ratio of increase in the works of nature
is neither true nor possible. It would fling into utter confusion all
order, time, magnitude, and space."

This is as curious a specimen of reasoning as any that has been offered
to the world since the days when theories were founded on the principle
that nature abhors a vacuum. We proceed a few pages further, however;
and we then find that geometric progression is unnatural only in those
cases in which Mr Malthus conceives that it exists; and that, in all
cases in which Mr Malthus denies the existence of a geometric ratio,
nature changes sides, and adopts that ratio as the rule of increase.

Mr Malthus holds that subsistence will increase only in an arithmetical
ratio. "As far as nature has to do with the question," says Mr Sadler,
"men might, for instance, plant twice the number of peas, and breed
from a double number of the same animals, with equal prospect of their
multiplication." Now, if Mr Sadler thinks that, as far as nature is
concerned, four sheep will double as fast as two, and eight as fast as
four, how can he deny that the geometrical ratio of increase does
exist in the works of nature? Or has he a definition of his own for
geometrical progression, as well as for inverse proportion?

Mr Malthus, and those who agree with him, have generally referred to
the United States, as a country in which the human race increases in a
geometrical ratio, and have fixed on thirty-five years as the term in
which the population of that country doubles itself. Mr Sadler contends
that it is physically impossible for a people to double in twenty-five
years; nay, that thirty-five years is far too short a period,--that
the Americans do not double by procreation in less than forty-seven
years,--and that the rapid increase of their numbers is produced