A debt is an obligation between approximate equals that can be precisely quantified. It only arises in the context of exchange, as opposed to other modes of economic interaction. One of the problems with debt is that as it extends or deepens it appears to make nearly absolute claims on our relationships converting things which wouldn’t otherwise be even possible to purchase into commodities: for example people.
Graeber examines the history of slavery and how it has invariably been connected to indebtedness, but he notes an interesting trend in many cultures, those he calls “human economies” (in other words pre-modern), which is that there are almost always a variety of intense culture taboos, provisions for eradicating debt before it reaches the point of enslavement. Enslavement occurs only when the stakes are ratcheted up with violence. In human economies turning something which is not a commodity (a person) into a commodity (a slave) can only be done when debt and violence are both present. Even if I’m in debt to you there is no way I will sell myself into slavery to pay the debt unless the consequences for not doing so are extreme violence against me or my family.
What this reveals, in Graeber’s estimation, is how violent our supposedly civilized industrialized culture is even though the violence is greatly sublimated. Most of us sell ourselves as commodities (wage laborers) every day. Think about how remarkable that is. Through most of human history the only way a person could be turned into a commodity was through massive debt and overt violence. Now we commodify ourselves routinely and even assume this is the way it has to be. There is no other option.
Another mark goes in the column labeled “patriarchy is the most evil thing of all evil things” when Graeber highlights how invariably the first people to be commodified and enslaved are women. In fact, it has always been the fuzzy ground women rest on in most cultures, partly a possession of their fathers and husbands, that has made it so easy to slip from paying debts with livestock, goods, or currency to paying debts with human beings. Trafficking in women for sex and labor might be the very essence of capitalism: that a human being can be purchased to satisfy my needs.