Athens is said by Plato to be a very great city; and it was surely the greatest of all the Greek​[74] cities, except Syracuse, which was nearly about the same size in Thucydides’ time, and afterwards increased beyond it; for Cicero​[75] mentions it as the greatest of all the Greek cities in his time, not comprehending, I suppose, either Antioch or Alexandria under that denomination. Athenæus says that, by the enumeration of Demetrius Phalereus, there were in Athens 21,000 citizens, 10,000 strangers, and 400,000 slaves. This number is very much insisted on by those whose opinion I call in question, and is esteemed a fundamental fact to their purpose; but, in my opinion, there is no point of criticism more certain than that Athenæus and Ctesicles, whom he cites, are here mistaken, and that the number of slaves is augmented by a whole cypher, and ought not to be regarded as more than 40,000. Firstly, when the number of citizens is said to be 21,000 by Athenæus,​[76] men of full age are only understood. For (1) Herodotus says that Aristagoras, ambassador from the Ionians, found it harder to deceive one Spartan than 30,000 Athenians, meaning in a loose way the whole state, supposed to be met in one popular assembly, excluding the women and children. (2) Thucydides says that, making allowance for all the absentees in the fleet, army, garrisons, and for people employed in their private affairs, the Athenian Assembly never rose to five thousand. (3) The forces enumerated by the same historian,​[77] being all citizens, and amounting to 13,000 heavy-armed infantry, prove the same method of calculation, as also the whole tenor of the Greek historians, who always understand men of full age when they assign the number of citizens in any republic. Now, these being but the fourth of the inhabitants, the free Athenians were by this account 84,000, the strangers 40,000, and the slaves, calculating by the smaller number, and allowing that they married and propagated at the same rate with freemen, were 160,000, and the whole inhabitants 284,000—a large enough number surely. The other number, 1,720,000, makes Athens larger than London and Paris united. Secondly, there were but 10,000 houses in Athens. Thirdly, though the extent of the walls, as given us by Thucydides, be great (viz., eighteen miles, beside the sea-coast), yet Xenophon says there was much waste ground within the walls. They seemed indeed to have joined four distinct and separate cities.​[78] Fourthly, no insurrection of the slaves, nor suspicion of insurrection, are ever mentioned by historians, except one commotion of the miners.