In a pre-industrial agricultural society, slavery or something similar (serfdom etc.) tends to be widespread, as human and animal muscles are the only reliable and ubiquitous source of energy. Humanity only really started getting rid of unfree backbreaking work by adopting steam engines. 300-400 years ago, most of us forists here would be unfree people working the fields in unfavorable conditions, with maybe 5 per cent being burghers and 1 per cent nobility.
> slavery or something similar (serfdom etc.)
Serfdom is very different from slavery. Even slavery is not always as bad as Roman slavery.
Roman slaves could be legally killed, tortured and raped (even children). Serfs might not have fair access to the law but at least in theory they had recourse and society recognised mistreating them was immoral.
Serfs could (meaningfully) marry. They were tied to the land so could not be separated from their families and sold elsewhere.
"Serfdom is very different from slavery."
And Mac is very different from a PC, but they are still personal computers that pack some computing power...
My wider point was about unfree labor in pre-industrial conditions. There were many serf uprisings in Central Europe, which indicates that being a serf was sometimes very hard to bear.
We are so used to free labor nowadays that we can't really imagine a world where the vast majority of the population is physically subjugated to some lords.
My point is that Roman slavery was a lot more brutal than what was required by the lack of technology.
I beeeive (I cannot find hard data, although things like the Doomsday book should have recorded some snapshots of it) while there was a large serf population, it was not the "vast majority" as there were also lots of free peasants.
Yes, it was a hard life, but far better than their equivalents would have suffered under Roman rule.
It's not that pre-industrial society causes slavery, it's closer to the other way round. If you're pre-industrial then everyone has to do farm work, yes, but slavery is /economically inefficient/ because the slaves don't provide demand (since you don't pay them) and don't grow the economy.
This is why economics was called "the dismal science" - economists told people to stop doing slavery and the slaveowners called them nerds. They wanted to own slaves because they wanted to be mini-tyrants, not because they were good at capitalism. Adam Smith did not go around telling people to own slaves.
You are right that slavery is economically inefficient and that economists were one of the fiercest crusaders against slavery etc.
However: lack of demand is not a problem. People can create any amount of total nominal demand for basically free, as long as you have access to a printing press. (And with some minor caveats that's generally true in a gold standard setting, too.)
And even without that: your argumentation would suggest that as long as the slave-owners lavishly spend the money they save on wages, the economy would do just as well as without slavery. That's not the case; have a look at the arguments of the very economists you mention.
Nope. If the only kilowatts at your disposal are the ones that you, your slaves and your horses can digest, you cannot just upscale the production of goods (or anything else) arbitrarily. The whole economy is bottlenecked on production which is bottlenecked on energy supply. Increasing the demand when supply is the problem would only make things worse.
However once you're burning coal (or harness the wind in case of dutch) things are very different, kilowatts flow freely and all the things you say above start to be true.
From 1000-1700 there was increasing wealth in Europe not through serfdom intensifying (but see Poland) but through increased trade, fishing, agricultural improvements and culminating in the steam engine. Watermills were medieval inventions.
Smith's pin factory has no steam engine. Nor did Slaters mill which created US industrialization. Steam required institutions to grow, institutions that had created growth earlier.
Watermills are pretty limited technology, though. It is advantageous to build them on rivers in hilly terrain, which is usually far from the seaports that are used for trade. Hilly terrain is also often agriculturally subpar, therefore you need to import food for the workers from the lowland, making the operation more expensive.
Finally, medieval watermills cannot produce heat, which is absolutely necessary for production of iron and steel. Which means that you cannot increase production of iron and steel beyond pre-modern levels, a major obstacle in development of technical civilization.
Agreed, and that is aligned with the point I'm making: bottleneck was the production, not consumption. Saying that increased consumption of freed slaves would somehow pull you out of pre-industrial age (the comment I was replying to) is just bonkers.
The increased production was indeed a result of centuries of incremental improvements. You're right to point out that some of them were not about energy, but I would argue that all of the big ones were.
Slaters mill put hydropower to work and even though watermills were medieval, the machines that poured that energy into cotton weren't. Same with the windmills during the Dutch Golden Age which I mentioned above. Increased trade happened through massive wind-powered ships, not slave galleys. (Though the Smith pin factory unlike the Slaters mill is not a real factory but a criticized thought experiment, I wouldn't consider it too influential)
But yes, indeed the steam appeared at the right time, only when there was enough technology to put it to use down the line.
I would say that inventing new technologies is one of the things that isn't possible when you've enslaved the inventors and made them farmworkers.
I mean, making them do research might work. That's a command economy, aka actually existing communism. Should be able to invent the waterwheel and crop rotation.
I do think it's hard to invent antibiotics and the Haber-Bosch process, and without that you are still in a Malthusian economy where everyone's going to die if they slack off farming.
Well yes, but how is this even relevant to the conversation? No one says innovation thrives with slavery. The point made is very simple, it's about commandable energy and EROI in particular. No amount of antibiotics can change that.