Communism

Indentured servitude was a huge step up from slavery though. It was (at least in Europe) a direct result of feudalism: just like the Duke swears allegiance to the king, gives him levies and taxes in exchange for protection, the serf was in a kind of feudal relationship. He received protection and a land to work (or a job in general) in exchange for a tithe and days of free labor. He wasn't treated as a commodity, bought and sold at a market, he was more like an apprentice, a subordinate or something of that kind.

E: i apparently confused classical servitude with indentured servitude💀 point still stands, slaves were slaves and there was no way for slaves to be freed if not by will of their masters.

E: also, goes without saying, if you were born a slave you would (most likely) have died a slave and so on for your children. It wasn't like that for indentured serfs, the contracts were signed for a specific amount of time, and they could "purchase their liberty" through their labor. Still an unjust system, but comparing it to slavery is just watering down the term tbh.