What the reason is that cities once grown to a greatness increase not onward according to that proportion
Let no man think the ways and means aforesaid, or any other that may be any way devised, can work or effect it that a city may go on in increase without ceasing. And therefore it is in truth a thing worth the consideration how it comes to Pass that cities grown to a point of greatness and power pass no further, but either stand at that stay, or else return back again. Let us take for our example Rome.
Rome, at her beginning, when she was founded and built by Romulus (as Dionysius of Halicarnassus writeth) was able to make out three thousand three hundred fit men for the wars. Romulus reigned thirty-seven years, within the compass of which time the city was increased even to forty-seven thousand persons fit to bear arms. About one hundred and fifty years after the death of Romulus, in the time of Servius Tullius, there were numbered in Rome eighty thousand persons fit for arms. The number in the end, by little and little, grew to four hundred and fifty thousand.
My question therefore is, how it comes to pass that from three thousand and three hundred men of war the people grew to four hundred and fifty thousand, and from four hundred and fifty thousand they went no further. And in like matter, since it is four hundred years since Milan and Venice made as many people as they do at this day, how it doth also come to pass that the multiplication goes not onward accordingly.
Some answer the cause hereof is the plagues, the wars, the dearths and other suchlike causes. But this gives no satisfaction. For plagues have ever been, and wars have been more common and more bloody in former times than now. For in those days they came to hand strokes by and by, and to a main pitched battle in the field, where there were within three or four hours more people slain than are in these days in many years. For war is now drawn out of the field to the walls, and the mattock and the spade are now more used than the sword. The world besides was never without alteration and change of plenty and of dearth, of health and of plagues. thereof I shall not need to bring examples, because the histories are full.
Now if cities with all these accidents and chances begun at first with a few people increase to a great number of inhabitants, how comes it that proportionably they do not increase accordingly?
Some others say it is because God the Governor of all things doth so dispose. No man doth doubt of that; but forasmuch as the infinite wisdom of God, in the administration and the government of nature, worketh secondary causes, my question is with what means that Eternal Providence maketh little to multiply, and much to stand at a stay and go no further.
Now to answer this propounded question I say, the selfsame question may be also made of all mankind, forasmuch as within the compass of three thousand years it multiplied in such sort from one man and one woman as the provinces of the whole continent and the islands of the sea were full of people. thence it doth proceed that from those three thousand years to this day this multiplication hath not exceeded further.
Now that I may the better resolve this doubt I purpose to answer it, as mine answer may not only serve for the cities, but also for the universal theatre of the world.
I say then, that the augmentation of cities proceedeth partly out of the virtue generative of men, and partly out of the virtue nutritive of the cities. The virtue generative is without doubt to this day the very same, or at least such as it was before three thousand years were passed, forasmuch as men are at this day as apt for generation as they were in the times of David or of Moses. So that if there were no other impediment or let therein, the propagation of mankind would. increase without end, and the augmentation of cities would be without term. And if it do not increase in infinite I must needs say it proceedeth of the defect of nutriment and sustenance sufficient for it.
