In general it may be said that demand is quite as necessary to the increase of capital as the increase of capital is to demand.

The most effectual encouragement to population is, the activity of industry, and the consequent multiplication of the national products.

It has appeared that from the inevitable laws of our nature, some human beings must suffer from want. These are the unhappy persons who, in the great lottery of life, have drawn a blank.

It has been said, and perhaps with truth, that the conclusions of Political Economy partake more of the certainty of the stricter sciences than those of most of the other branches of human knowledge.

The exertions that men find it necessary to make, in order to support themselves or families, frequently awaken faculties that might otherwise have lain for ever dormant, and it has been commonly remarked that new and extraordinary situations generally create minds adequate to grapple with the difficulties in which they are involved.

[P]opulation, when unchecked, goes on doubling itself every twenty-five years, or increases in a geometrical ratio. ... [T]he means of subsistence, under circumstances the most favorable to human industry, could not possibly be made to increase faster than in an arithmetical ratio.

Subsistence increases only in an arithmetical ratio.