The government under which, without external means, without naturalisations, without colonies, the citizens become populous and multiply the most, is infallibly the best government.
Gist of Idea
The measure of a successful state is increase in its population
Jean-Jacques Rousseau (The Social Contract (tr Cress) , III.09)
I'm not sure if this was true in the eighteenth century. Birth control has entirely changed the picture, since affluent people seem less inclined to breed. Presumably poverty increased famine and infant mortality.
Rousseau,Jean-Jacques: 'The Basic Political Writings', ed/tr. Cress,Donald A. [Hackett 1987], p.191