Aristotle, Politics

[1327a] [1] and in addition, on the other hand, the same thing holds good of the territory that we said about the size of the population—it must be well able to be taken in at one view, and that means being a country easy for military defence. As to the site of the city, if it is to be ideally placed, it is proper for it to be well situated with regard both to the sea and to the country. One defining principle is that mentioned above¹—the city must be in communication with all parts of the territory for the purpose of sending out military assistance; and the remaining principle is that it must be easily accessible for the conveyance to it of the agricultural produce, and also of timber-wood and any other such material that the country happens to possess.

As to communication with the sea it is in fact much debated whether it is advantageous to well-ordered states or harmful. It is maintained that the visits of persons brought up under other institutions are detrimental to law and order, and so also is a swollen population, which grows out of sending out abroad and receiving in a number of traders, but is unfavorable to good government. Now it is not difficult to see that, if these consequences are avoided, it is advantageous in respect of both security and the supply of necessary commodities [20] that the city and the country should have access to the sea. With a view to enduring wars more easily people that are to be secure must be capable of defensive operations on both elements, land and sea, and with a view to striking at assailants, even if it be not possible on both elements, yet to do so on one or the other will be more in the power of people that have access to both. And the importation of commodities that they do not happen to have in their own country and the export of their surplus products are things indispensable; for the state ought to engage in commerce for its own interest, but not for the interest of the foreigner. People that throw open their market to the world do so for the sake of revenue, but a state that is not to take part in that sort of profit-making need not possess a great commercial port. But since even now we see many countries and cities possessing sea-ports and harbors conveniently situated with regard to the city, so as not to form part of the same town² and yet not to be too far off, but commanded by walls and other defence-works of the kind, it is manifest that if any advantage does result through the communication of city with port the state will possess this advantage, and if there is any harmful result it is easy to guard against it by means of laws stating and regulating what persons are not and what persons are to have intercourse with one another. On the question of naval forces, there is no doubt that to possess them up to a certain strength is most desirable