Aristotle next looks at certain mundane but important considerations for the success of political organizations: the extent of territory and the size of population, access to the sea, and the influence of climate.
The Ideal Population Size of a State
As you might imagine, on the question of the ideal population for a state, Aristotle is in his goldilocksian element: A state must neither be so small that it does not have enough people to perform its basic functions, nor so large that it is unmanageable, but there is a middle-range of populations that are ideal.
Some of the reasons Aristotle gives for why a good polis cannot continue to scale up past a certain population limit are these:
- Experience has shown that it is difficult to run a populous state by good laws. This is in part because disorder increases as a state grows large, and good laws and good order go hand-in-hand.
- A state is kind of like other complex things — animals, plants, instruments. They have a normal range of sizes and do not function well when they are too far outside of that range.
- It is difficult to fill some positions when the population grows too large: who could be commander-in-chief over such a huge militia? who would have the voice to be town crier to a town of enormous size?
One is tempted to accuse Aristotle of a lack of imagination and to wonder if we have overcome some of this. After all, we no longer need a town crier whose voice can carry over the crowd of citizens in order to debate or announce policy, for example. And national militaries seem to have figured out how to have unified military commands in spite of their size (though this has inflated the depth of the officer corps enormously, such that, for example, a dozen U.S. Generals were deployed among the 5,000-person force initially sent to fight the Islamic State). Maybe the other limitations Aristotle assumed have been or can be similarly overcome.
(Interestingly, one analogy he gives for why a state cannot scale without limit is that although you can make boats of many sizes, a one-meter-long boat isn’t really a functioning boat, and neither would be one 380 meters long. A list of the longest ships found on Wikipedia shows that they tend to max out at around 400 meters. So: Pretty close, Aristotle!)
Aristotle’s main criterion for deciding whether your polis has gotten too big is whether or not “the citizens should know each other and know what kind of people they are.” Unless we can know one another sufficiently well, we won’t know whom to trust (and in particular who can be trusted to hold official positions) and the leaders won’t be able to understand the people they lead well enough to do so well. Also, it will be more difficult to distinguish between citizens and foreigners or resident aliens: since nobody looks familiar, everybody looks more or less the same, and cohesion melts back into the inchoate.
A Greek polis in Aristotle’s time typically had maybe ten thousand people living under it. Big ones would have ten or fifteen times that. Athens, the biggest of the bunch, had maybe thirty thousand citizens among a population maybe ten times that large. So that gives you some idea of the range of populations Aristotle has in mind. When he says that large cities have been shown to be governed haphazardly and poorly, he’s talking about this sort of upper range.
The Ideal Territory of a City and State
A good place to put a state is one where there are raw materials at hand and good productive land, where a foreign military force will have a difficult time invading or surrounding but from which your own military (or messengers to and from allies) won’t be hindered, and where there is good access to the sea. It should be easy to get the lay of the land. Something of a slope is ideal, facing east into the wind.
Aristotle is equivocal about trade and immigration. On the one hand, he thinks having sea ports is good for a polis, both for military purposes and for trade. But he doesn’t seem to think much of cities that orient themselves around being a marketplace or free port. He is also concerned that a large navy might be a source of democratic agitation, as it apparently had been in Athens, where ordinary uncouth trireme rowers managed to make citizens out of themselves in exchange for their service.
He next speculates about the effect of climate on peoples and states. The people of Europe “are full of spirit, but somewhat lacking in skill and intellect,” while the people of Asia seem the other way around. Greece, lying in the middle, has been blessed with the best of both worlds. But no sooner has he said this but he notices that Greece has a lot of variety: some people more like the Europeans, some more like the Asians. So maybe climate isn’t the answer. In any case: spirit, skill, and intellect are all useful things to have in your population and contribute to a better-functioning state.
Finally, Aristotle counsels against the advice of those who would encourage citizens to be hostile or foreboding to foreign visitors. “[F]ierceness is not a mark of natural greatness of mind except towards wrongdoers.”
City Layout and Facilities
The qualities that make a city easy to navigate and efficient to travel in also tend to make it easier to invade and conquer, so there’s a trade-off to consider. It may be best to lay out the street plan of individual neighborhoods regularly, but have them meet irregularly at the boundaries, so as to get something of the best of both worlds.
As for the perennial topic of walls, while there is something dishonorable about hiding behind them, they do have use in military defense, and cities that have disclaimed them entirely have paid the price for it. This is especially the case now that artillery has improved. Watchtowers, as they will be distributed regularly along the walls, are good locations to put your communal dining facilities.
Water should be abundant and close-by. Cisterns to collect rainwater are an alternative for secure water supply if springs are far away or hard to defend.
A central, easily-defended area for religious and government facilities is a good idea. A recreational park, distinct from the marketplace and free from commercial activity, is worth including as well as a marketplace proper, which is best located close to where shipping takes place. Government bureaus concerned with contracts and other business matters should be nearby the market.
But Aristotle is just sort of rushing through these considerations. He doesn’t mean to be writing a manual of city planning, just to give an overview of some of the things worthy of consideration.