In a state therefore of great equality and virtue, where pure and simple manners prevailed, the increase of the human species would evidently be much greater than any increase that has been hitherto known.

I think it will be found that experience, the true source and foundation of all knowledge, invariably confirms its truth.

The power of population is indefinitely greater than the power in the earth to produce subsistence for man.

Population, when unchecked, goes on doubling itself every 25 years or increases in a geometrical ratio.