to a statement which Malthus, at any rate, might regard as
undeniable; namely, that in a country already fully occupied, the
possibility of increasing produce is restricted within much narrower
limits. In a 'new country,' as in the American colonies, the increase
of food might proceed as rapidly as the increase of population.
Improved methods of cultivation, or the virtual addition of vast
tracts of fertile territory by improved means of communication, may of
course add indefinitely to the resources of a population. But Malthus
was contemplating a state of things in which the actual conditions
limited the people to an extraction of greater supplies from a
strictly limited area. Whether Malthus assumed too easily that this
represented the normal case may be questionable. At any rate, it was
not only possible but actual in the England of the time. His problem
was very much to the purpose. His aim was to trace the way in which
the population of a limited region is prevented from increasing
geometrically. If the descendants of Englishmen increase at a certain
rate in America, why do they not increase equally in England? That, it
must be admitted, is a fair scientific problem. Finding that two races
of similar origin, and presumably like qualities, increase at
different rates, we have to investigate the causes of the difference.

Malthus answered the problem in the simplest and most consistent way
in his first edition. What are the checks? The ultimate check would
clearly be starvation. A population might multiply till it had not
food. But before this limit is actually reached, it will suffer in
various ways from scarcity. Briefly, the checks may be distinguished
into the positive, that is, actual distress, and the preventive, or
'foresight.' We shall actually suffer unless we are restrained by the
anticipation of suffering. As a fact, however, he thinks that men are
but little influenced by the prudence which foresees sufferings. They
go on multiplying till the consequences are realised. You may be
confined in a room, to use one of his illustrations,[220] though the
walls do not touch you; but human beings are seldom satisfied till
they have actually knocked their heads against the wall. He sums up
his argument in the first edition in three propositions.[221]
Population is limited by the means of subsistence; that is obvious;
population invariably increases when the means of subsistence are
increased; that is shown by exper