The great and unlooked for discoveries that have taken place of late years have all concurred to lead many men into the opinion that we were touching on a period big with the most important changes.

Nature herself in times of great poverty or bad climatic conditions, as well as poor harvest, intervenes to restrict the increase of population of certain countries or races; this, to be sure, by a method as wise as it is ruthless.

The first business of philosophy is to account for things as they are; and till our theories will do this, they ought not to be the ground of any practical conclusion.

In prosperous times the mercantile classes often realize fortunes, which go far towards securing them against the future; but unfortunately the working classes, though they share in the general prosperity, do not share in it so largely as in the general adversity.

The most baleful mischiefs may be expected from the unmanly conduct of not daring to face truth because it is unpleasing.

The superior power of population cannot be checked without producing misery or vice.

The perpetual struggle for room and food.