With regard to the duration of human life, there does not appear to have existed from the earliest ages of the world to the present moment the smallest permanent symptom or indication of increasing prolongation.

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.

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

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 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.

The germs of existence contained in this spot of earth, with ample food, and ample room to expand in, would fill millions of worlds in the course of a few thousand years.

If it be taught that all who are born have a right to support on the land, whatever be their number, and that there is no occasion to exercise any prudence in the affair of marriage so as to check this number, the temptations, according to all the known principles of human nature, will inevitably be yielded to, and more and more will gradually become dependent on parish assistance.