A feather will weigh down a scale when there is nothing in the opposite one.

The immediate cause of the increase of population is the excess of the births above deaths; and the rate of increase, or the period of doubling, depends upon the proportion which the excess of the births above the deaths bears to the population.

The redundant population, necessarily occasioned by the prevalence of early marriages, must be repressed by occasional famines, and by the custom of exposing children, which, in times of distress, is probably more frequent than is ever acknowledged to Europeans.

It accords with the most liberal spirit of philosophy to suppose that not a stone can fall, or a plant rise, without the immediate agency of divine power.

It does not, however, seem impossible that by an attention to breed, a certain degree of improvement, similar to that among animals, might take place among men. Whether intellect could be communicated may be a matter of doubt: but size, strength, beauty, complexion, and perhaps even longevity are in a degree transmissible... As the human race could not be improved in this way, without condemning all the bad specimens to celibacy, it is not probable, that an attention to breed should ever become general.

The doctrine of population has been conspicuously absent, not because I doubt in the least its truth and vast importance, but because it forms no part of the direct problem of economics.

On the whole it may be observed, that the specific use of a body of unproductive consumers, is to give encouragement to wealth by maintaining such a balance between produce and consumption as will give the greatest exchangeable value to the results of the national industry.