Whether the law of marriage be instituted or not, the dictate of nature and virtue seems to be an early attachment to one woman.

The finest minds seem to be formed rather by efforts at original thinking, by endeavours to form new combinations, and to discover new truths, than by passively receiving the impressions of other men's ideas.

The natural inequality of the two powers of population and of production in the earth, and that great law of our nature which must constantly keep their efforts equal, form the great difficulty that to me appears insurmountable in the way to the perfectibility of society.

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.

No limits whatever are placed to the productions of the earth; they may increase forever.

Population trends have always provoked doom-fraught oracles, because their popular interpreters suppose that every new series will be infinitely sustained; yet, beyond the short term, expectations based on them are never fulfilled.

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.