I am rereading Moses Finlay’s The Ancient Economy for our book called The Time of Troubles (outline soon). Despite the flaws of Finlay’s study, it is still a great read. For example:

Or when Thucydides (7.27.5) tells us that more than 20,000 slaves escaped from Attica in the final decade of the Peloponnesian War, just what do we in fact know? Did Thucydides have a network of agents stationed along the border between Attica and Boeotia for ten years counting the fugitives as they sneaked across? This is not a frivolous question, given the solemnity with which his statement is repeated in modern books and then used as the basis for calculations and conclusions. The context indicates that Thucydides thought the loss a severe blow to Athens. A modern historian would surely have gone on to indicate what proportion of the total slave population 2o,ooo represented. Thucydides did not, because he did not know the total, nor did anyone else in Athens. It follows that the 2o,ooo is no more than a guess; we can only hope that it was an educated guess (24).