If Virgil is in some ways a follower of Plato, Plato would certainly not have agreed with him on the need for world empire. Like most of the Greeks Plato thought that a limited population was necessary for a good political community. The Greek view seems to have been formed by the experience of the war with Persia. In book VII of Herodotus’ Histories Demaratus famously tells Xerxes that the Greeks will win for,
though free, yet they are not free in all things, for over them is set Law as a master, whom they fear much more even than thy people fear thee. It is certain at least that they do whatsoever that master commands; and he commands ever the same thing, that is to say, he bids them not flee out of battle from any multitude of men, but stay in their post and win the victory or lose their life.
This will later be taken to mean that the Greeks won because they are ruled by reason, whereas the Persians are ruled by passion or appetite. Xerxes thrashing the sea is the enduring symbol of the folly of unruly passion. Despotism corresponds to the rule of the passions just as polity to the rule of reason. Just as appetite has no measure and goes to excess, so the despot seeks to rule over ever greater masses of people; but reason, seeking the golden mean, places limits on the size of the polity.
Aristotle holds that the mean in this case is “the largest number which suffices for the purposes of life, and can be taken in at a single view,” for,
a state when composed of too few is not, as a state ought to be, self-sufficing; when of too many, though self-sufficing in all mere necessaries, as a nation may be, it is not a state, being almost incapable of constitutional government. For who can be the general of such a vast multitude, or who the herald, unless he have the voice of a Stentor? (Politics VII, 1326a)
The rule of law depends on political virtue, but political virtue depends on political participation, and this depends on limited population. For only a limited number can deliberate together. Noting that Plato limits the number of guardians in the Republic to 1000 but increases the number to 5000 in the Laws, Aristotle treats this number as a kind of joke:
The discourses of Socrates are never commonplace; they always exhibit grace and originality and thought; but perfection in everything can hardly be expected. We must not overlook the fact that the number of 5000 citizens, just now mentioned, will require a territory as large as Babylon, or some other huge site, if so many persons are to be supported in idleness, together with their women and attendants, who will be a multitude many times as great. In framing an ideal we may assume what we wish, but should avoid impossibilities. (Politics II, 1265a 10-15)
The impossibility comes from a limit on the power of human reason:
experience shows that a very populous city can rarely, if ever, be well governed; since all cities which have a reputation for good government have a limit of population. We may argue on grounds of reason, and the same result will follow. For law is order, and good law is good order; but a very great multitude cannot be orderly: to introduce order into the unlimited is the work of a divine power- of such a power as holds together the universe. (Politics VII, 1326a)
That is, human reason, unlike the divine reason which rules the universe, is unable to order more than a few thousand men. But this position involves a paradox. Is not human nous a kind of divine power? Is reason not universal? If reason is one and everywhere the same and always commands the same thing then why must reasonable beings be divided? In Metaphysics XII Aristotle argues that the power that governs the universe is one, for “the world refuses to be governed badly: ‘The rule of many is not good; one ruler let there be.'” (1076a) Does the world of men not refuse to be governed badly? Is it to remain forever a waring multitude of rival cities? Eve Adler points out (pp. 202-203) that this is exactly the point that Plutarch makes in the Moralia, in which he argues that Alexander the Great was a greater political philosopher than Aristotle or Plato, for he saw the political implications of the reasonable nature of man. That’s all very well, but Plato and Aristotle might respond that Plutarch himself describes how Alexander ends his life like an oriental despot…
(to be continued)