Imagine a world in which there are 3 men, who each spend two thirds of their time working simply to stay alive, and who spend the remainder idle. They might be farmers, or hunters, or fishermen. They could be depicted as follows:
Now let’s suppose that man 1 enslaves man 2 (don’t ask how!), and gets him to do some of his work. Man 2 is already working for two thirds of his time staying alive. It’s only in his idle time that he can work for man 1. So after man 2 becomes man 1’s slave, the situation becomes:
Now let’s suppose that man 1 enslaves man 3 as well as man 2. The same logic as before applies, and the new state can be depicted like this:
Now man 1 lives a perfectly idle life. He is free to do whatever he likes. In Athens, this meant, among other things, that he could spend his days in the Grove of Academe, listening to Socrates or Plato talking about virtue or justice. But man 2 and man 3 are kept busy all day. They never get a moment of relaxation. They are completely constrained.
I think that the above process describes the logic of slavery in the ancient world. If you wanted to be a free man (like man 1), you had to enslave other men. There was no other way to attain freedom. And if you weren’t prepared to enslave other men, then most likely other men would enslave you.
In the example above, one man needs 2 slaves to attain freedom. But that assumes that the underlying idleness (the fraction of their time anyone is idle) is 33.3%. But what if underlying idleness is lower, or higher? How many slaves are needed then?
If I represents underlying or mean idleness, then the number of slaves N anyone needs to achieve complete freedom is given by:
N = ( 1 – I ) / I
So if I is 50%, N = 1. And if I is 25%, N = 3. And if I = 10%, N = 9. And if I is 1%, N = 99. The lower the mean idleness of human existence, the higher the number of slaves needed.
And this suggests that when average or mean idleness is very low, slavery becomes impossible. Prospective slave-owners can only capture slaves in their idle time, and when mean idleness is very low they are simply too busy to find the idle time in which to go capturing slaves. And when they do manage to catch any, these slaves are unable to do very much work for them anyway.
But once slaves have been captured, and the slave-owner has more idle time, he can catch slaves more easily. The first slave is the hardest to get, but after that it gets easier. And this suggests that in antiquity the appearance of slavery was very sudden, and communities of equals (equally idle) were replaced almost overnight by communities divided into free masters and toiling slaves.
So, what was the proportion of slaves to free men in antiquity? Here’s the philosopher David Hume:
ATHENÆUS says, that, by the enumeration of DEMETRIUS PHALEREUS, there were in ATHENS 21,000 citizens, 10,000 strangers, and 400,000 slaves.
That’s 13 slaves per free man, suggesting that the mean idleness of Athens circa 310 BC was 7%.
However, Hume simply doesn’t believe these figures, and says that the number of slaves must be ten times too many, because otherwise they would have revolted. And then he says that the 21,000 citizens and strangers would have had wives and children, and so their numbers must be multiplied by 4, so that there are now 124,000 citizens, and 40,000 slaves. One slave for every three citizens, and an implicit Athenian mean idleness of 75%.
Personally, I’m more inclined to believe Athenaeus than Hume. Why should Athenaeus multiply the numbers of slaves by 10? And since the status of women and children in Athens was far inferior to that of men, why should they have been provided with hard-to-obtain slaves as well? And would those ‘strangers’ have had wives and families and slaves? Surely most of the strangers would have been traders, briefly visiting Athens to conduct business. They would have left their wives and children at home, far from Athens.
Fourthly, No insurrection of the slaves, or suspicion of insurrection, is ever mentioned by historians; except one commotion of the miners.
Fifthly, The treatment of slaves by the ATHENIANS is said by XENOPHON, and DEMOSTHENES, and PLAUTUS, to have been extremely gentle and indulgent: Which could never have been the case, had the disproportion been twenty to one. The disproportion is not so great in any of our colonies; yet are we obliged to exercise a rigorous military government over the negroes.
If there were no slave revolts in Athens, it was probably precisely because slaves were treated ‘extremely gently and indulgently’. Which suggests that they weren’t kept busy working all the time, and weren’t very much busier than the toiling wives and children of the free citizens of Athens, and that the mean idleness of Athens was probably nearer 10% or 15% rather than 7%. Slaves are likely to revolt if their conditions are unendurable (as in the mines), and their is some prospect of freedom elsewhere. But clearly in Athens the slave existence was not intolerable, and should they have managed to escape, they would have found themselves working almost as hard, wherever they went.
Seventhly, During the DECELIAN war, as the GREEK historians call it, 20,000 slaves deserted, and brought the ATHENIANS to great distress, as we learn from THUCYDIDES. This could not have happened, had they been only the twentieth part. The best slaves would not desert.
In time of war, life gets harder (i.e. less idle). During the Decelian war, the pampered slaves of Athens were almost certainly required to work harder. And this may have become intolerable for many of them. And as slaves deserted, their burden of work would have fallen not on the remaining slaves in Athens (already fully occupied) but on the remaining free men and their wives and children. Of course it would have caused great distress.
I suggested in my last essay that the institution of slavery only came to an end once technological innovation (steam trains and factories and ships) rendered it obsolete, just like cars and buses and trams rendered horses redundant in the early 20th century. If the mean idleness of Britain is now, say, 75%, a free man only needs one third of a slave. He needs a part-time slave.
And perhaps part-time employment, 7 hours a day, is just our current version of slavery.